Ultrasound enhanced thrombolysis for stroke.
Alexandrov Andrei V
International journal of stroke : official journal of the International Stroke Society
In the pivotal clinical trials of intravenous tissue plasminogen activator (TPA) therapy, a low rate of early arterial recanalization was suspected because only a few stroke patients may have had early dramatic clinical improvement. Tissue plasminogen activator activity can be enhanced with ultrasound, including 2 MHz transcranial Doppler (TCD). Transcranial Doppler identifies residual blood flow signals around thrombi, and, by delivering mechanical pressure waves, exposes more thrombus surface to circulating TPA. For the first time in clinical medicine, the international multicenter CLOTBUST trial showed that ultrasound enhances the thrombolytic activity of a drug in humans, thereby confirming multidisciplinary experimental research conducted worldwide for the past 30 years. In the CLOTBUST trial, the dramatic clinical recovery from stroke coupled with complete recanalization within 2 h after TPA bolus occurred in 25% of patients treated with TPA+TCD compared with 8% who received TPA alone (P=0.02). Complete clearance of a thrombus and dramatic recovery of brain functions during treatment are feasible goals for ultrasound-enhanced thrombolysis that can lead to sustained recovery. An early boost in brain perfusion seen in the target CLOTBUST group resulted in a trend of 13% more patients achieving favorable outcome at 3 months. To further enhance the ability of TPA to break up thrombi, current ongoing clinical trials include phase II studies of 2 MHz TCD with ultrasound contrast agents or (microbubbles): TCD+TPA+Levovist; TCD+TPA+MRX nano-platform (C(3)F(8)). Intra-arterial TPA delivery can be enhanced with 1 x 7-2 x 1 MHz pulsed wave ultrasound (EKOS catheter, IMS trial). Dose escalation studies of microbubbles, ultrasound exposure, and the development of an operator-independent ultrasound device are underway.
Asymptomatic embolisation for prediction of stroke in the Asymptomatic Carotid Emboli Study (ACES): a prospective observational study.
Markus Hugh S,King Alice,Shipley Martin,Topakian Raffi,Cullinane Marisa,Reihill Sheila,Bornstein Natan M,Schaafsma Arjen
The Lancet. Neurology
BACKGROUND:Whether surgery is beneficial for patients with asymptomatic carotid stenosis is controversial. Better methods of identifying patients who are likely to develop stroke would improve the risk-benefit ratio for carotid endarterectomy. We aimed to investigate whether detection of asymptomatic embolic signals by use of transcranial doppler (TCD) could predict stroke risk in patients with asymptomatic carotid stenosis. METHODS:The Asymptomatic Carotid Emboli Study (ACES) was a prospective observational study in patients with asymptomatic carotid stenosis of at least 70% from 26 centres worldwide. To detect the presence of embolic signals, patients had two 1 h TCD recordings from the ipsilateral middle cerebral artery at baseline and one 1 h recording at 6, 12, and 18 months. Patients were followed up for 2 years. The primary endpoint was ipsilateral stroke and transient ischaemic attack. All recordings were analysed centrally by investigators masked to patient identity. FINDINGS:482 patients were recruited, of whom 467 had evaluable recordings. Embolic signals were present in 77 of 467 patients at baseline. The hazard ratio for the risk of ipsilateral stroke and transient ischaemic attack from baseline to 2 years in patients with embolic signals compared with those without was 2.54 (95% CI 1.20-5.36; p=0.015). For ipsilateral stroke alone, the hazard ratio was 5.57 (1.61-19.32; p=0.007). The absolute annual risk of ipsilateral stroke or transient ischaemic attack between baseline and 2 years was 7.13% in patients with embolic signals and 3.04% in those without, and for ipsilateral stroke was 3.62% in patients with embolic signals and 0.70% in those without. The hazard ratio for the risk of ipsilateral stroke and transient ischaemic attack for patients who had embolic signals on the recording preceding the next 6-month follow-up compared with those who did not was 2.63 (95% CI 1.01-6.88; p=0.049), and for ipsilateral stroke alone the hazard ratio was 6.37 (1.59-25.57; p=0.009). Controlling for antiplatelet therapy, degree of stenosis, and other risk factors did not alter the results. INTERPRETATION:Detection of asymptomatic embolisation on TCD can be used to identify patients with asymptomatic carotid stenosis who are at a higher risk of stroke and transient ischaemic attack, and also those with a low absolute stroke risk. Assessment of the presence of embolic signals on TCD might be useful in the selection of patients with asymptomatic carotid stenosis who are likely to benefit from endarterectomy. FUNDING:British Heart Foundation.
What influenced the lesion patterns and hemodynamic characteristics in patients with internal carotid artery stenosis? A retrospective study.
Liu Jinjie,Wang Hong,Zhang Meiyan,Sui Xiaowen,Li Furong,Liu Zanhua,Liu Sibo,Zhao Hongling
Neurologia i neurochirurgia polska
OBJECTIVES:This study aimed to explore the dynamic changes of lesion patterns and hemodynamic characteristics in patients with internal carotid artery stenosis (ICAS). PATIENTS AND METHODS:Patients who had suffered an acute ischemic stroke in the distribution of ipsilateral ICAS were included. Computed tomography (CT) and transcranial doppler ultrasound (TCD) were conducted to evaluate the degree of ICAS and the hemodynamic characteristics of the intracranial and extracranial arteries. RESULT:A total of 424 patients were included in the study. With the aggravation of ICAS, blood velocity in ipsilateral ICA was increased, while blood flow in the ipsilateral middle cerebral artery (MCA) was decreased. In the same degree of ICAS, patients with opened communicating arteries showed relatively higher blood perfusion in MCA compared with those without communicating arteries. In the average stage of ICAS, small lesions (D=0-1.5cm), middle lesions (1.5cm<D≤3.0cm) and large lesions (D>3.0cm) commonly existed. The number of small and large lesions significantly increased when the blood flow of ipsilateral MCA decreased. In the same degree of stenosis, the number of small lesions and large lesions, and the total area of all lesions, evidently increased with the decrease of ipsilateral MCA blood velocity. CONCLUSION:Hypoperfusion is an independent risk factor for ischemic lesions in patients with ICAS. Whether or not the communicating arteries are open influences the blood flow of the intracranial arteries. TCD was a convenient and rapid tool to assess intracranial perfusion and vascular compensatory status.
Predictors of cerebral reperfusion injury after carotid stenting: the role of transcranial color-coded Doppler ultrasonography.
Kablak-Ziembicka Anna,Przewlocki Tadeusz,Pieniazek Piotr,Musialek Piotr,Tekieli Lukasz,Rosławiecka Agnieszka,Motyl Rafal,Zmudka Krzysztof,Tracz Wieslawa,Podolec Piotr
Journal of endovascular therapy : an official journal of the International Society of Endovascular Specialists
PURPOSE:To evaluate the possible role of transcranial color-coded Doppler ultrasonography (TCD) in predicting cerebral reperfusion injury (CRI) in patients undergoing carotid artery stenting (CAS) for internal carotid artery (ICA) stenosis. METHODS:TCD was obtained in 210 patients (149 men; mean age 64.2+/-8.4 years, range 44-83) who underwent CAS for ICA stenosis averaging 86.7%+/-8.4%. Contralateral ICA occlusion or near occlusion (stenosis >90%) was present in 67 (31.9%) patients. TCD was performed before and 24 hours after CAS with assessment of peak systolic velocities (PSVs) in the ipsilateral middle cerebral artery (iMCA) and contralateral middle cerebral artery (cMCA). PSV ratios (PSVR) in the iMCA and cMCA were calculated from the PSVs before and after CAS. RESULTS:CRI syndrome occurred in 3 (1.4%) patients (2 intracranial bleedings, 1 subarachnoid hemorrhage). The mean iMCA and cMCA PSVRs were 2.66+/-0.19 and 4.16+/-2.77, respectively, in CRI patients, while the PSVRs in CAS patients without neurological sequelae were 1.56+/-0.46 and 1.21+/-0.39, respectively (both p<0.001). The combination of iPSVR>2.4 and cPSVR>2.4 occurred in 4 patients with bilateral ICA disease; 3 (75%) of them developed CRI (100% sensitivity and 99% specificity for CRI prediction). The following independent CRI predictors were identified: combined iPSVR>2.4 and cPSVR>2.4 (RR 2.06, CI 1.89 to 2.24; p<0.001), high cMCA PSV after CAS (RR 1.23, CI 1.13 to 1.34; p<0.001), and contralateral ICA occlusion (RR 1.13, CI 1.03 to 1.23; p = 0.007). CONCLUSION:TCD is an important tool in CRI risk evaluation. The combination of iPSVR>2.4 and cPSVR>2.4 is an independent CRI risk factor, along with contralateral ICA occlusion and high cMCA PSVs after CAS.
Low rates of acute recanalization with intravenous recombinant tissue plasminogen activator in ischemic stroke: real-world experience and a call for action.
Bhatia Rohit,Hill Michael D,Shobha Nandavar,Menon Bijoy,Bal Simerpreet,Kochar Puneet,Watson Tim,Goyal Mayank,Demchuk Andrew M
BACKGROUND AND PURPOSE:Acute rates of recanalization after intravenous (IV) recombinant tissue plasminogen activator (rt-PA) in proximal vessel occlusion have been estimated sparingly, typically using transcranial Doppler (TCD). We aimed to study acute recanalization rates of IV rt-PA in CT angiogram-proven proximal (internal carotid artery [ICA], M1 middle cerebral artery [MCA], M2-MCA, and basilar artery) occlusions and their effects on outcome. MATERIALS AND METHODS:The CT angiogram database of the Calgary stroke program was reviewed for the period 2002 to 2009. All patients with proximal vessel occlusions receiving IV rt-PA who were assessed for recanalization by TCD or angiogram (for acute endovascular treatment) were included for analysis. Rates of acute recanalization as observed on TCD/first run of angiogram and postendovascular therapy recanalization rates were noted. Modified Rankin Scale score ≤2 at 3 months was used as a good outcome. RESULTS:Among 1341 patients in the CT angiogram database, 388 patients with proximal occlusion were identified. Of these, 216 patients had received IV rt-PA; 127 patients underwent further imaging to assess recanalization. Among the patients undergoing TCD (n=46) and cerebral angiogram (n=103), only 27 (21.25%) patients had acute recanalization. By occlusion subtype, the rates of recanalization were: distal ICA (with or without ICA neck occlusion or stenotic disease) 1 of 24 (4.4%); M1-MCA (with or without ICA neck occlusion or stenotic disease) 21 of 65 (32.3%); M2-MCA 4 of 13 (30.8%); and basilar artery 1 of 25 (4%). Onset to rt-PA time was comparable in patients with and without recanalization. Recanalization (P<0.0001; risk ratio, 2.7; 95% confidence interval, 1.5-4.6) was the strongest predictor of outcome (adjusted for age and National Institutes of Health Stroke Scale score). CONCLUSIONS:A low rate of acute recanalization was observed with IV rt-PA in proximal vessel occlusions identified by baseline CT angiogram. Recanalization was the strongest predictor of good outcome.
[Intraoperative neuromonitoring for prevention of neurological complications in aortic surgery].
Langer S,Koeppel T A,Greiner A,Kalder J,Keschenau P R,Mess W H,Jacobs M J
Zentralblatt fur Chirurgie
AIM:Stroke and paraplegia are devastating complications of thoracic and thoracoabdominal aortic surgery. The aim of this study was to analyse the value of transcranial Doppler ultrasound (TCD), electroencephalogram (EEG) and motor-evoked potentials (MEP) in preventing neurological complications. Moreover, the principles, technology and surgical protocols are described. PATIENTS AND METHODS:In 2009, 22 patients (4 females, 18 males) underwent thoracic or thoracoabdominal open aortic repair. We performed 2 arches with descending aortic replacement, 5 arches with TAAA repair, 2 type II, 9 type III, 3 type IV and one type V TAAA aortic repair. In 6 patients, the neuromonitoring included TCD, EEG and MEPs. In 15 patients only MEP monitoring was necessary. In one patient who was operated on in an emergency setting, neuromonitoring was not performed. The surgical approach was a left thoracotomy in 3 and a left thoracolaparotomy in 19 patients. The surgical protocol included cerebrospinal fluid drainage (n=22), moderate (n=19) or deep hypothermia (n=2), and extracorporeal circulation (n=21) with retrograde aortic perfusion and selective cerebral and/or viscerorenal perfusion. RESULTS:In 21 patients, the neuromonitoring could be established successfully. Using TCD and EEG, a relevant cerebral ischaemia during supraaortic clamping was excluded. With a mean distal arterial pressure of 60 mmHg, the MEPs remained adequate in 15 patients (68.2%). Increasing of the blood pressure restored the MEPs in one patient. In 5 patients (22.7%), a reimplantation of segmental arteries (n=4) or of the left subclavian artery (n=1) re-established spinal cord perfusion, as indicated by restored MEPs. We had no absent MEPs at the end of the procedures. Delayed paraparesis developed in 2 patients with a haemodynamic instability during the postoperative course. Paraplegia was not observed. CONCLUSION:TCD, EEG and MEPs are reliable techniques to unmask cerebral or spinal cord ischaemia during aortic surgery. Immediate operative strategies based on neuromonitoring information prevent neurological complications in aortic surgery.
Transcranial Doppler sonography pulsatility index (PI) reflects intracranial pressure (ICP).
Bellner Johan,Romner Bertil,Reinstrup Peter,Kristiansson Karl-Axel,Ryding Erik,Brandt Lennart
BACKGROUND:In patients with intracranial pathology, especially when comatose, it is desirable to have knowledge of the intracranial pressure (ICP). To investigate the relationship between ICP and transcranial Doppler (TCD) derived pulsatility index (PI) in neurosurgical patients, a prospective study was performed on patients admitted to our neurointensive care unit. METHODS:Daily TCD mean flow velocity (mFV) measurements were made. TCD measurements were routinely performed bilaterally on the middle cerebral artery (MCA). PI (peak systolic-end diastolic velocities/mean flow velocity) was calculated. RESULTS:Eighty-one patients with various intracranial disorders who had an intraventricular catheter for registration of the ICP were investigated: 46 (57%) patients had subarachnoid hemorrhage, 21 (26%) patients had closed head injury, and 14 (18%) patients had other neurosurgical disorders. A total of 658 TCD measurements were made. ICP registrations were made parallel with all TCD measurements. A significant correlation (p < 0.0001) was found between the ICP and the PI with a correlation coefficient of 0.938: ICP = 10.93 x PI - 1.28. In the ICP interval between 5 to 40 mm Hg the correlation between ICP and PI enabled an estimation of ICP from the PI values with an SD of 2.5. The correlation between the cerebral perfusion pressure (CPP) and PI was significant (p < 0.0001) with a correlation coefficient of -0.493. When separating the measurements in severely elevated (>120 cm/s) and subnormal (<50 cm/s) TCD mFV values, the correlation coefficient between ICP and PI was 0.828 (p < 0.002) and 0.942 (p < 0.638), respectively. CONCLUSIONS:Independent of the type of intracranial pathology, a strong correlation between PI and ICP was demonstrated. Therefore, PI may be of guiding value in the invasive ICP placement decision in the neurointensive care patient.
Evaluation of cerebrovascular reserve in patients undergoing carotid artery stenting and its usefulness in predicting significant hemodynamic changes during temporary carotid occlusion.
Spacek M,Stechovsky C,Horvath M,Hajek P,Zimolova P,Veselka J
We investigated the usefulness of cerebrovascular reserve (CVR) testing to predict severe hemodynamic changes during proximally protected carotid artery stenting. Of 90 patients referred, 63 eligible underwent complete evaluation of the extent of carotid artery disease and transcranial Doppler ultrasound (TCD) assessment of CVR by means of a breath-holding test and ophthalmic artery flow pattern evaluation. Periprocedural TCD monitoring of the ipsilateral middle cerebral artery flow was performed in 24 patients undergoing proximally protected procedure (requiring induction of flow arrest within internal carotid artery). Abnormal CVR was significantly less common in patients with unilateral compared to bilateral carotid artery disease (26.3 % vs. 76.9 %, p=0.02), while ophthalmic artery flow reversal was rare in patients with unilateral carotid artery disease (2.5 % vs. 42.9 %, p<0.01). During the induction of carotid flow arrest, the average mean flow velocity drop following external carotid artery occlusion was low (3.5 %, p=0.67) compared to the induction of complete flow arrest (32.8 %, p<0.01). Six patients had a total mean flow velocity drop >50 %, including 2 patients with normal pre-procedural CVR. Our results suggest that TCD evaluation of CVR is not a reliable predictor of hemodynamic changes induced during proximally protected carotid artery stenting in patients with unilateral carotid artery disease.
Pre and postoperative evaluation of transcranial Doppler pulsatility index of the middle cerebral artery in patients with severe carotid artery stenosis.
Bracale Umberto Marcello,Spalla Flavia,Caioni Federica,Solari Domenico,Narese Donatella,Pecoraro Felice,Del Guercio Luca
Annali italiani di chirurgia
UNLABELLED:In the management of severe carotid artery stenosis particular importance must be given to the evaluation of the risk of perioperative cerebral ischemic events. Our study analysed the possible relationship between the pre-operative middle cerebral artery Gosling Index, calculated after transcranial Doppler (TCD), and intra-operative stump pressure (SP), in order to identify patients with higher risk of ischemic accidents. Moreover, we studied pre- and post- operative Gosling Index values in association with possible events during follow-up. In a one-year time lapse 47 patients underwent either carotid endoarterectomy (CEA) or carotid artery stenting (CAS) with proximal embolic protection system. All patients were subject to pre- and post-operative TCD with calculation of the Gosling Index and intra-operative SP. We observed that higher pre-operative Gosling Index values are associated with lower intra-operative SP values, elements that represent a higher risk for cerebro-vascular ischemic accidents; this result is particularly evident when observing the diabetic sub-population. An increase in ischemic events did not present statistically significant differences when observing the populations treated with CEA or CAS. TCD and SP are valid and simple exams that can help identify precociously patients with a higher risk of cerebro-vascular accidents related to surgical or endovascular treatment. KEY WORDS:Carotid artery stenosis, Carotid endarterectomy, Endovascular treatment.
Transcranial Doppler Ultrasound: Physical Principles and Principal Applications in Neurocritical Care Unit.
D'Andrea Antonello,Conte Marianna,Scarafile Raffaella,Riegler Lucia,Cocchia Rosangela,Pezzullo Enrica,Cavallaro Massimo,Carbone Andreina,Natale Francesco,Russo Maria Giovanna,Gregorio Giovanni,Calabrò Raffaele
Journal of cardiovascular echography
Transcranial Doppler (TCD) ultrasonography is a noninvasive ultrasound study, which has been extensively applied on both outpatient and inpatient settings. It involves the use of a low-frequency (≤2 MHz) transducer, placed on the scalp, to insonate the basal cerebral arteries through relatively thin bone windows and to measure the cerebral blood flow velocity and its alteration in many different conditions. In neurointensive care setting, TCD is useful for both adults and children for day-to-day bedside assessment of critical conditions including vasospasm in subarachnoid hemorrhage, traumatic brain injury, acute ischemic stroke, and brain stem death. It also allows to investigate the cerebrovascular autoregulation in setting of carotid disease and syncope. In this review, we will describe physical principles underlying TCD, flow indices most frequently used in clinical practice and critical care applications in Neurocritical Unit care.
[Value of cerebrovascular hemodynamics analysis on diagnosis of cerebral microcirculation disorder].
Sun L,Zhang X L,Zhang H J
Zhonghua yi xue za zhi
OBJECTIVE:To determine the clinical value of cerebrovascular hemodynamics analysis (CVA) on cerebral microcirculation. METHODS:One hundred consecutive patients from neurological department of Peking University People's Hospital from April to October, 2015, with symptoms of dizziness, lightheadedness, headache etc., who were diagnosed with ischemic cerebrovascular disease with normal transcranial doppler (TCD) and abnormal CVA, were recruited in this study.Other medical conditions were excluded through clinic and imaging examinations among these patients.Patients were categorized into mild, moderate and severe subgroups based on the degrees of decreased blood flow velocity and/or volume, and received treatment accordingly.CVA parameters including the minimum flow velocity (Vmin), the minimum flow volume (Qmin), peripheral resistance (R), critical pressure (CCP) and dynamic resistance (CVR) etc.before and after treatment were compared statistically (t test). RESULTS:Out of the 100 patients with abnormal CVA, 52 patients had bilateral changes and 48 patients had unilateral changes.The minimum flow velocity and the minimum flow volume anomalies were found in 100 and 92 cases, respectively.A total of 47, 32 and 21 patients had mild, moderate and severe abnormal changes, respectively.Out of the 63 patients who had follow-up CVA after treatment (drop-out 37 cases), there were 63 abnormal Vmin cases, 60 abnormal Qmin cases, 17 abnormal R cases, 18 abnormal CCP cases, 41 abnormal characteristic impedance (Zc) cases, 41 abnormal elastic wave velocity (Wv) cases, 23 abnormal vascular compliance (C) cases, all before treatment.After treatment, symptoms and Vmin synchronization improved in 61 cases (96.8%), Qmin improved in 58 cases (96.6%), R improved in 13 cases (76.5%), CCP improved in 10 cases (55.6%), Zc improved in 27 cases (65.8%), Wv improved in 25 cases (61.0%), C improved in 6 cases (26.1%). All improvements were statistically significant (P<0.05), with Vmin, Qmin, R and CCP showing most significant changes (P<0.000 1). The CVR treatment showed no significant before and after treatment (P>0.05). CONCLUSIONS:CVA is an important method in assessing cerebral microcirculation perfusion, providing information on intracranial microvascular bed that cannot be detected by TCD.It is not only helpful for diagnosis, but also evaluable for monitoring clinical treatment of cerebral microcirculation disorder.CVA is also helpful in determining the location of cerebral circulation impairment by correlation with carotid ultrasound and TCD.
The curative effect comparison of two kinds of therapeutic regimens on decreasing the relative intensity of microembolic signal in CLAIR trial.
Deng Q Q,Tang J,Chen C,Markus H,Huang Y N,Zhao H,Ratanakorn D,Wong K S L,Fu J H
Journal of the neurological sciences
BACKGROUND:Microembolic signals (MESs) are direct markers of unstable large artery atherosclerotic plaques. In a previous study, we found that the number of MESs is associated with stroke recurrence and that clopidogrel plus aspirin more effectively reduce the number of MESs than does aspirin alone. Stroke recurrence is associated with not only the number of MESs but also the size of the MES, which can theoretically be estimated by monitoring the MES intensity via transcranial doppler (TCD). Thus, we compared the effects of clopidogrel and aspirin with aspirin alone on MES intensity using TCD. METHODS:We recruited 100 patients who experienced acute ischemic stroke or transient ischemic attack (TIA) within 7days of symptom onset. All patients also had large artery stenosis in the cerebral or carotid arteries and the presence of MES as revealed by TCD. The patients were randomized to receive either aspirin or clopidogrel and aspirin for 7days. MES monitoring was performed on days 2 and 7. RESULTS:Intent-to-treat (ITT) analysis (46 patients in the dual therapy group, 52 patients in the monotherapy group) and per-protocol (PP) analysis (25 patients in the dual therapy group, 31 patients in the monotherapy group) were performed on 98 patients. The primary finding was that the MES intensity was dramatically reduced in the dual therapy group. ITT analysis of the dual therapy group revealed that the MES intensity was 8.04 (0-16) dB before treatment, 0.00 (0-17) dB on day 2, and 0.00 (0-12) dB on day 7 (P=0.000). In the monotherapy group, the MES intensity was 9.00 (0-20) dB before treatment, 8.25 (0-17) dB on day 2, and 7.0 (0-18) dB on day 7 (P=0.577). PP analysis revealed similar results. No severe hemorrhagic complications were detected. The two patients in this study who experienced stroke recurrence were in the monotherapy group. CONCLUSIONS:Clopidogrel and aspirin more effectively decrease the MES intensity than aspirin alone in patients with large artery stenotic minor stroke or TIA.
Role of transcranial Doppler in cerebrovascular disease.
Kulkarni Amit A,Sharma Vijay K
Transcranial Doppler (TCD) is the only noninvasive modality for the assessment of real-time cerebral blood flow. It complements various anatomic imaging modalities by providing physiological-flow related information. It is relatively cheap, easily available, and can be performed at the bedside. It has been suggested as an essential component of a comprehensive stroke centre. In addition to its importance in acute cerebrovascular ischemia, its role is expanding in the evaluation of cerebral hemodynamics in various disorders of the brain. The "established" clinical indications for the use of TCD include cerebral ischemia, sickle cell disease, detection of right-to-left shunts, subarachnoid hemorrhage, periprocedural or surgical monitoring, and brain death. We present the role of TCD in acute cerebrovascular ischemia, sonothrombolysis, and intracranial stenosis.
Transcranial Doppler and cerebral augmentation in acute ischemic stroke.
Saqqur Maher,Ibrahim Mohamed,Butcher Ken,Khan Khurshid,Emery Derek,Manawadu Dulka,Derksen Carol,Schwindt Brenda,Shuaib Ashfaq
Journal of neuroimaging : official journal of the American Society of Neuroimaging
BACKGROUND:Collateral flow augmentation using partial aortic occlusion may improve cerebral perfusion in acute stroke. We assessed the effect of partial aortic occlusion on arterial flow velocities of acute stroke patients. METHODS:Patients with neurological deficits following thrombolysis were treated with partial aortic occlusion. Transcranial Doppler ultrasound (TCD) was used to measure arterial flow velocities at baseline, before and during balloon inflation. The augmented mean flow velocity (MFV), peak systolic velocity (PSV), and end diastolic velocity flow percentages (aMFV%, aPSV%, aEDV%) were calculated and compared based on outcome. RESULTS:Of 11 patients, 3 did not have a temporal window and thus were excluded from our analysis. Six of the remaining 8 patients had middle cerebral artery (MCA) occlusions; the final 2 had terminal internal carotid artery (TICA) occlusions. Three of these 8 patients had good outcome at 90 days (mRS < 3). Before intra-aortic balloon inflation (IABI), the mean affected artery MFV was 23 ± 11 cm/s; during the procedure it was 26 ± 12 cm/s (P = .2). Mean affected artery PSV at baseline and during balloon inflation were 37 ± 16 and 46 ± 23, respectively (P = .1). Mean augmented affected artery MFV% in patients with good long-term outcome was 65.4 ± 46, while the result in those with poor outcome was -3.7 ± 21 (P = .03). Three patients developed anterior cross-filling, and of these 2 had good long-term outcome. CONCLUSION:TCD monitoring of patients treated with IABI may help in predicting outcome in this novel device.
Staged carotid artery angioplasty and stenting for patients with high-grade carotid stenosis with high risk of developing hyperperfusion injury: a retrospective analysis of 44 cases.
Mo Dapeng,Luo Gang,Wang Bo,Ma Ning,Gao Feng,Sun Xuan,Xu Xiaotong,Miao Zhongrong
Stroke and vascular neurology
BACKGROUND:Hyperperfusion syndrome (HPS) is a rare but potentially a life-threatening complication after carotid artery angioplasty and stenting (CAS). Staged CAS has been an alternative to prevent HPS. MATERIALS AND METHODS:44 of 908 patients with high-grade internal carotid artery stenosis or near occlusion were at risk of HPS because of poor collateral flow and impaired cerebral blood flow (CBF). They were treated with first (stage 1), followed by a full CAS (stage 2) 1 month later. Their 30-day outcomes were tabulated and analysed. RESULTS:During follow-up, 1 of the 44 (2.2%) patients developed HPS immediately, 3 (7%) had postprocedural HPS (ie, transcranial Doppler (TCD) >120%) without clinical symptoms and 3 (7%) required stenting at stage 1 for carotid dissections. After stage 1, there were significant improvement between the preprocedural and postprocedural CBF (0.98±0.06 vs 0.85±0.05, p<0.05), mean transit time (MTT; 1.05±0.05 vs 1.15±0.05, p<0.05), time to peak (TTP; 1.04±0.06 vs 1.20±0.06, p<0.05) on CT perfusion (CTP), and CBF (66.41±7.41 vs 44.44±6.43, p<0.05) on TCD. After stage 2, improvement was seen in CBF (1.01±0.07 vs 0.98±0.06, p<0.05), MTT (1.01±0.05 vs 1.05±0.05, p<0.05), TTP (0.99±0.06 vs 1.04±0.06, p<0.05) on CTP and CBF (66.41±7.41 vs 93.78±18.81, p<0.05) on TCD. 2 had postoperative increase of middle cerebral artery mean flow velocity of 120% after stage 2 without clinical symptoms. CONCLUSION:Staged carotid artery stenting probably decreased the chance of developing HPS in this group of selected patients. Although requiring a 2-step intervention, staged CAS may be a safe and effective alternative.
Cerebral monitoring during carotid endarterectomy by transcranial Doppler ultrasonography.
Annals of surgical treatment and research
PURPOSE:To evaluate the efficacy and safety of cerebral monitoring by transcranial Doppler ultrasonography (TCD) for the detection of cerebral ischemia during carotid endarterectomy (CEA). METHODS:From August 2004 to December 2013, 159 CEAs were performed in a tertiary hospital. All procedures were performed under general anesthesia. Intraoperative TCD was routinely used to detect cerebral ischemia. Of the 159 patients, 102 patients were included in this study, excluding 27 patients who had a poor transtemporal isonation window and 30 patients who used additional cerebral monitoring systems such as electroencephalography or somatosensory evoked potentials. When mean flow velocity in the ipsilateral middle cerebral artery decreased by >50% versus baseline during carotid clamping carotid shunting was selectively performed. The carotid shunt rate and incidence of perioperative (<30 days) stroke or death were investigated by reviewing medical records. RESULTS:Carotid shunting was performed in 31 of the 102 patients (30%). Perioperative stroke occurred in 2 patients (2%); a minor ischemic stroke caused by embolism in one and an intracerebral hemorrhage in the other. Perioperative death developed in the latter patient. CONCLUSION:TCD is a safe cerebral monitoring tool to detect cerebral ischemia during CEA. It can reduce use of carotid shunt.
The accuracy of transcranial Doppler in excluding intracranial hypertension following acute brain injury: a multicenter prospective pilot study.
Rasulo Frank A,Bertuetti Rita,Robba Chiara,Lusenti Francesco,Cantoni Alfredo,Bernini Marta,Girardini Alan,Calza Stefano,Piva Simone,Fagoni Nazzareno,Latronico Nicola
Critical care (London, England)
BACKGROUND:Untimely diagnosis of intracranial hypertension may lead to delays in therapy and worsening of outcome. Transcranial Doppler (TCD) detects variations in cerebral blood flow velocity which may correlate with intracranial pressure (ICP). We investigated if intracranial hypertension can be accurately excluded through use of TCD. METHOD:This was a multicenter prospective pilot study in patients with acute brain injury requiring invasive ICP (ICPi) monitoring. ICP estimated with TCD (ICPtcd) was compared with ICPi in three separate time frames: immediately before ICPi placement, immediately after ICPi placement, and 3 hours following ICPi positioning. Sensitivity and specificity, and concordance correlation coefficient between ICPi and ICPtcd were calculated. Receiver operating curve (ROC) and the area under the curve (AUC) analyses were estimated after measurement averaging over time. RESULTS:A total of 38 patients were enrolled, and of these 12 (31.6%) had at least one episode of intracranial hypertension. One hundred fourteen paired measurements of ICPi and ICPtcd were gathered for analysis. With dichotomized ICPi (≤20 mmHg vs >20 mmHg), the sensitivity of ICPtcd was 100%; all measurements with high ICPi (>20 mmHg) also had a high ICPtcd values. Bland-Altman plot showed an overestimation of 6.2 mmHg (95% CI 5.08-7.30 mmHg) for ICPtcd compared to ICPi. AUC was 96.0% (95% CI 89.8-100%) and the estimated best threshold was at ICPi of 24.8 mmHg corresponding to a sensitivity 100% and a specificity of 91.2%. CONCLUSIONS:This study provides preliminary evidence that ICPtcd may accurately exclude intracranial hypertension in patients with acute brain injury. Future studies with adequate power are needed to confirm this result.
Diagnostic impact of early transcranial Doppler ultrasonography on the TOAST classification subtype in acute cerebral ischemia.
Wijman C A,McBee N A,Keyl P M,Varelas P N,Williams M A,Ulatowski J A,Hanley D F,Wityk R J,Razumovsky A Y
Cerebrovascular diseases (Basel, Switzerland)
OBJECTIVE:The impact of early transcranial Doppler ultrasonography (TCD) upon stroke subtype diagnosis is unknown and may affect therapeutic strategies. In this study, the diagnostic usefulness of TCD in stroke subtype diagnosis according to the criteria of the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) study was investigated in patients with acute cerebral ischemia. METHODS:TCD examination within 24 h of symptom onset was performed in 50 consecutive patients with acute cerebral ischemia. Of these 54% were female. Sixty percent of patients were black, 36% white, and 4% Asian. Initial TOAST stroke subtype diagnosis (ITSSD) was based upon clinical presentation and initial brain imaging studies. Modified TOAST stroke subtype diagnosis was determined subsequently after additional review of the TCD examination. Final TOAST stroke subtype diagnosis was determined at hospital discharge, incorporating all diagnostic studies. Using final TOAST stroke subtype diagnosis as the 'gold standard' ITSSD and modified TOAST stroke subtype diagnosis were compared in order to determine additional benefit from the information obtained by TCD. Data were collected retrospectively by a single investigator. RESULTS:ITSSD classified 23 of 50 (46%) patients correctly. After TCD, 30 of 50 (60%) patients were classified correctly, for an absolute benefit of 14% and a relative benefit of 30% (p = 0.018). Most benefit from TCD was observed in the TOAST stroke subtype category large-artery atherosclerosis, in particular in patients with intracranial vascular disease. In this category, ITSSD had a sensitivity of 27% which increased to 64% after TCD (p = 0.002). CONCLUSION:TCD within 24 h of symptom onset improves the accuracy of early stroke subtype diagnosis in patients with acute cerebral ischemia due to large-artery atherosclerosis. This may have clinical implications for early therapeutic interventions.
Transcranial Doppler identification of changing autoregulatory thresholds after autoregulatory impairment.
Lewis S B,Wong M L,Bannan P E,Piper I R,Reilly P L
OBJECTIVE:Transcranial Doppler (TCD) flow velocity (FV) assessment may provide a useful index of autoregulatory impairment after severe head injury. It may define a therapeutic end point against which cerebral perfusion pressure (CPP) can be titrated. This study examines the relationship between cerebral blood flow (CBF) and TCD FV indices in a laboratory model before and after autoregulatory impairment. METHODS:CPP, CBF, and middle cerebral artery TCD FV were measured continuously in nine anesthetized and ventilated sheep. CPP was decreased by hemorrhagic hypotension. The process was repeated after impairment of autoregulation by cisternal infusion, which maintained CPP at 0 mm Hg for 15 minutes. Points of significant change (i.e., breakpoints) from baseline values for each of the measured flow parameters were identified by using a ratio of variance technique. RESULTS:Before any significant change in CBF or systolic TCD, diastolic TCD FV decreased (mean breakpoint, 69 mm Hg; range, 56-78 mm Hg) as CPP was reduced. This divergence of diastolic and systolic TCD FV, which occurred before autoregulatory failure, was associated with an increasing TCD pulsatility index (mean breakpoint, 63 mm Hg; range, 53-70 mm Hg). At diastolic TCD FV congruent with 10 cm/s, systolic TCD FV (mean breakpoint, 48 mm Hg; range, 46-53 mm Hg) and CBF (mean breakpoint, 49 mm Hg; range, 47-51 mm Hg) decreased rapidly, indicating autoregulatory failure. After autoregulatory impairment, the breakpoints for all four indices shifted to higher CPP values (mean, 16 mm Hg). CONCLUSION:TCD FV assessment identified two CPP thresholds of autoregulatory loss. Before autoregulatory failure, an earlier phase of autoregulatory disturbance may be detected by divergent systolic and diastolic TCD FVs. It is important to note that this phase may be detected before CBF decreases. These TCD FV breakpoints depend on the state of autoregulatory impairment and may provide potential targets for CPP-directed therapy.
Continuous Autoregulatory Indices Derived from Multi-Modal Monitoring: Each One Is Not Like the Other.
Zeiler Frederick A,Donnelly Joseph,Menon David K,Smielewski Peter,Zweifel Christian,Brady Ken,Czosnyka Marek
Journal of neurotrauma
We assess the relationships between various continuous measures of autoregulatory capacity in a cohort of adults with traumatic brain injury (TBI). We assessed relationships between autoregulatory indices derived from intracranial pressure (ICP: PRx, PAx, RAC), transcranial Doppler (TCD: Mx, Sx, Dx), brain tissue-oxygenation (ORx), and spatially resolved near infrared spectroscopy (NIRS resolved: TOx, THx). Relationships between indices were assessed using Pearson correlation coefficient, Friedman test, principal component analysis (PCA), agglomerative hierarchal clustering (AHC) and k-means cluster analysis (KMCA). All analytic techniques were repeated for a range of temporal resolutions of data, including minute-by-minute averages, moving means of 30 samples, and grand mean for each patient. Thirty-seven patients were studied. The PRx displayed strong association with PAx/RAC across all the analytical techniques: Pearson correlation (r = 0.682/r = 0.677, p < 0.0001), PCA, AHC, and KMCA in the grand mean data sheet. Most TCD-based indices (Mx, Dx) were correlated and co-clustered on PCA, AHC, and KMCA. The Sx was found to be more closely associated with ICP-derived indices on Pearson correlation, PCA, AHC, and KMCA. The NIRS indices displayed variable correlation with each other and with indices derived from ICP and TCD signals. Of interest, TOx and THx co-cluster with ICP-based indices on PCA and AHC. The ORx failed to display any meaningful correlations with other indices in neither of the analytical method used. Thirty-minute moving average and minute-by-minute data set displayed similar results across all the methods. The RAC, Mx, and Sx were the strongest predictors of outcome at six months. Continuously updating autoregulatory indices are not all correlated with one another. Caution must be advised when utilizing less commonly described autoregulation indices (i.e., ORx) for the clinical assessment of autoregulatory capacity, because they appear to not be related to commonly measured/establish indices, such as PRx. Further prospective validation is required.
Ultraearly assessed reperfusion status after middle cerebral artery recanalization predicting clinical outcome.
Gölitz P,Muehlen I,Gerner S T,Knossalla F,Doerfler A
Acta neurologica Scandinavica
OBJECTIVES:Mechanical thrombectomy has high evidence in stroke therapy; however, successful recanalization guarantees not a favorable clinical outcome. We aimed to quantitatively assess the reperfusion status ultraearly after successful middle cerebral artery (MCA) recanalization to identify flow parameters that potentially allow predicting clinical outcome. MATERIALS AND METHODS:Sixty-seven stroke patients with acute MCA occlusion, undergoing recanalization, were enrolled. Using parametric color coding, a post-processing algorithm, pre-, and post-interventional digital subtraction angiography series were evaluated concerning the following parameters: pre- and post-procedural cortical relative time to peak (rTTP) of MCA territory, reperfusion time, and index. Functional long-term outcome was assessed by the 90-day modified Rankin Scale score (mRS; favorable: 0-2). RESULTS:Cortical rTTP was significantly shorter before (3.33 ± 1.36 seconds; P = .03) and after intervention (2.05 ± 0.70 seconds; P = .003) in patients with favorable clinical outcome. Additionally, age (P = .005) and initial National Institutes of Health Stroke Scale score (P = .02) were significantly different between the patients, whereas reperfusion index and time as well as initially estimated infarct size were not. In multivariate analysis, only post-procedural rTTP (P = .005) was independently associated with favorable clinical outcome. 2.29 seconds for post-procedural rTTP might be a threshold to predict favorable clinical outcome. CONCLUSIONS:Ultraearly quantitative assessment of reperfusion status after successful MCA recanalization reveals post-procedural cortical rTTP as possible independent prognostic value in predicting favorable clinical outcome, even determining a threshold value might be possible. In consequence, focusing stroke therapy on microcirculatory patency could be valuable to improve outcome.
Thrombolysis in brain ischemia (TIBI) transcranial Doppler flow grades predict clinical severity, early recovery, and mortality in patients treated with intravenous tissue plasminogen activator.
Demchuk A M,Burgin W S,Christou I,Felberg R A,Barber P A,Hill M D,Alexandrov A V
BACKGROUND AND PURPOSE:TIMI angiographic classification measures coronary residual flow and recanalization. We developed a Thrombolysis in Brain Ischemia (TIBI) classification by using transcranial Doppler (TCD) to noninvasively monitor intracranial vessel residual flow signals. We examined whether the emergent TCD TIBI classification correlated with stroke severity and outcome in patients treated with intravenously administered tPA (IV-tPA). METHODS:TCD examination occurred acutely and on day 2. TIBI flows were determined at distal MCA and basilar artery depths, depending on occlusion site. TIBI waveforms were graded as follows: 0, absent; 1, minimal; 2, blunted; 3, dampened; 4, stenotic; and 5, normal. National Institutes of Health Stroke Scale (NIHSS) scores were obtained at baseline and 24 hours after administration of tPA. RESULTS:One hundred nine IV tPA patients were studied. Mean+/-SD age was 68+/-16 years; median NIHSS score before administration of tPA (pre-tPA) was 17.5. The tPA bolus was administered 143+/-58 minutes and the TCD examination 141+/-57 minutes after symptom onset. Pre-tPA NIHSS scores were higher in patients with TIBI grade 0 than TIBI grade 4 or 5 flow. TIBI flow improvement to grade 4 or 5 occurred in 35% of patients (19/54) with an initial grade of 0 or 1 and in 52% (12/23) with initial grade 2 or 3. The 24-hour NIHSS scores were higher in follow-up in patients with TIBI grade 0 or 1 than those with TIBI grade 4 or 5 flow. TIBI flow recovery correlated with NIHSS score improvement. Lack of flow recovery predicted worsening or no improvement. In-hospital mortality was 71% (5/7) for patients with posterior circulation occlusions; it was 22% (11/51) for patients with pre-tPA TIBI 0 or 1 compared with 5% (1/19) for those with pre-tPA TIBI 2 or 3 anterior circulation occlusions. CONCLUSIONS:Emergent TCD TIBI classification correlates with initial stroke severity, clinical recovery, and mortality in IV-tPA-treated stroke patients. A flow-grade improvement correlated with clinical improvement.
Speed of intracranial clot lysis with intravenous tissue plasminogen activator therapy: sonographic classification and short-term improvement.
Alexandrov A V,Burgin W S,Demchuk A M,El-Mitwalli A,Grotta J C
BACKGROUND:Arterial recanalization precedes clinical improvement or may lead to hemorrhage or reperfusion injury. Speed of clot lysis was not previously measured in human stroke. METHODS AND RESULTS:Transcranial Doppler (TCD) and the National Institutes of Health Stroke Scale (NIHSS) were used to monitor consecutive patients receiving intravenous tissue plasminogen activator (tPA), before tPA bolus and at 24 hours. Patients with complete or partial recanalization of the middle cerebral or basilar artery on TCD were studied. Recanalization was classified a priori as sudden (abrupt appearance of a normal or stenotic low-resistance signal), stepwise (flow improvement over 1 to 29 minutes), or slow (>/=30 minutes). Recanalization was documented in 43 tPA-treated patients (age 68+/-17 years; NIHSS score 16.8+/-6, median 15 points). tPA bolus was given at a mean of 135+/-61 minutes after symptom onset. Recanalization began at a median of 17 minutes and was completed at 35 minutes after tPA bolus, with mean duration of recanalization of 23+/-16 minutes. Recanalization was sudden in 5, stepwise in 23, and slow in 15 patients. Faster recanalization predicted better short-term improvement (P=0.03). At 24 hours, 80%, 30%, and 13% of patients in these respective recanalization groups had NIHSS scores of 0 to 3. Symptomatic hemorrhage occurred in only 1 patient, who had stepwise recanalization 5.5 hours after stroke onset. Slow or partial recanalization with dampened flow signal was found in 53% of patients with total NIHSS scores >10 points at 24 hours (P=0.01). Complete recanalization (n=25) occurred faster (median 10 minutes) than partial recanalization (n=18; median 30 minutes; P=0.0001). CONCLUSIONS:Rapid arterial recanalization is associated with better short-term improvement, mostly likely because of faster and more complete clot breakup with low resistance of the distal circulatory bed. Slow (>/=30 minutes) flow improvement and dampened flow signal are less favorable prognostic signs. These findings may be evaluated to assist with selection of patients for additional pharmacological or interventional treatment.
Does the administration of sonothrombolysis along with tissue plasminogen activator improve outcomes in acute ischemic stroke? A systematic review and meta-analysis.
Zafar Marium,Memon Roha Saeed,Mussa Muhammad,Merchant Rameez,Khurshid Aiman,Khosa Faisal
Journal of thrombosis and thrombolysis
This meta-analysis was conducted to assess the safety and efficacy of sonothrombolysis along with intravenous recombinant tissue plasminogen activator, alteplase (IV rtPA), in the management of acute ischemic stroke. Electronic databases were searched under different meSH terms without the restriction of time and language. 1415 studies were analyzed and seven studies that matched the inclusion criteria were selected. Multiple safety and efficacy outcomes were extracted. Our pooled analysis demonstrated that there is no significant difference between sonothrombolysis group and control group in preventing mortality (RR 1.10 [0.81, 1.50]; p = 0.55; I = 0%) and intracranial hemorrhage (RR 1.11 [0.76, 1.63]; p = 0.59; i = 0%), however, among the efficacy outcomes; complete recanalization after 60-120 min was achieved more effectively in the sonothrombolysis group (RR 2.11 [1.48, 3.03]; p ≤ 0.0001; I = 0%). The rest of the efficacy outcomes like neurological improvement at 24 h (RR 1.20 [0.92, 1.57]; p = 0.18; I = 40%) and excellent functional outcome after 3 months (RR 1.19 [0.93, 1.52]; p = 0.17; I = 35%) showed no significant differences between the two groups. In subgroup analysis, we found that sonothrombolysis led to a better neurological improvement in patients who were less than 65 years of age (RR 1.20 [0.92, 1.57]; p = 0.05; I = 40%). Moreover, there were no significant differences in the following of the subgroups assessed: (a) microsphere or microbubble use, (b) Ultrasound frequency (2 MHz or < 2 MHz), (c) transcranial Doppler (TCD) duration (1 h or 2 h), (d) age (≤ 65 or > 65).
Relationship between pulsatility index and clinical course of acute ischemic stroke after thrombolytic treatment.
Uzuner Nevzat,Özdemir Özcan,Tekgöl Uzuner Gülnur
BioMed research international
Background. The relationship between the arterial recanalization after intravenous recombinant tissue plasminogen activator (rtPA) and outcomes is still uncertain. The aim of our study was to evaluate whether there is an association between the pulsatility indexes (PI) of the middle cerebral artery (MCA) measured by transcranial Doppler (TCD) after iv rtPA treatment and short- and long-term outcomes in ischemic stroke patients. Methods. Forty-eight patients with acute ischemia in the MCA territory who achieved complete recanalization after the administration of intravenous thrombolytic treatment were included in the study. The TCD was applied to patients after the iv rtPA treatment. Clinical and functional outcomes were assessed by National Institutes of Health Stroke Scale (NIHSS) scores and modified Rankin Scores (mRS), respectively. Results. Significant positive correlations were found between the PI value and NIHSS score at 24 hours, NIHSS score at 3 months, and mRS at 3 months (P < 0.005 for all). The cut-off value for PI in predicting a favorable prognosis and a good prognosis might be less than or equal to 1.1 and less than or equal to 1.4, respectively. Conclusions. PI may play a role in predicting the functional and clinical outcome after thrombolytic therapy in acute ischemic stroke patients.
Early and continuous neurologic improvements after intravenous thrombolysis are strong predictors of favorable long-term outcomes in acute ischemic stroke.
Yeo Leonard L L,Paliwal Prakash,Teoh Hock L,Seet Raymond C,Chan Bernard P L,Wakerley Benjamin,Liang Shen,Rathakrishnan Rahul,Chong Vincent F,Ting Eric Y S,Sharma Vijay K
Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association
BACKGROUND:Intravenously administered tissue plasminogen activator (IV tPA) remains the only approved therapeutic agent for arterial recanalization in acute ischemic stroke (AIS). Considerable proportion of AIS patients demonstrate changes in their neurologic status within the first 24 hours of intravenous thrombolysis with IV tPA. However, there are little available data on the course of clinical recovery in subacute 2- to 24-hour window and its impact. We evaluated whether neurologic improvement at 2 and 24 hours after IV tPA bolus can predict functional outcomes in AIS patients at 3 months. METHODS:Data for consecutive AIS patients treated with IV tPA within 4.5 hours of symptom onset during 2007-2011 were prospectively entered in our thrombolyzed registry. National Institutes of Health Stroke Scale (NIHSS) scores were recorded before IV tPA bolus, at 2 and 24 hours. Early neurologic improvement (ENI) at 2 hours was defined as a reduction in NIHSS score by 10 or more points from baseline or an absolute score of 4 or less points at 2 hours. Continuous neurologic improvement (CNI) was defined as a reduction of NIHSS score by 8 or more points between 2 and 24 hours or an absolute score of 4 or less points at 24 hours. Favorable functional outcomes at 3 months were determined by modified Rankin Scale (mRS) score of 0-1. RESULTS:Of 2460 AIS patients admitted during the study period, 263 (10.7%) received IV tPA within the time window; median age was 64 years (range 19-92), with 63.9% being men, a median NIHSS score of 17 points (range 5-35), and a median onset-to-treatment time of 145 minutes (range 57-270). Overall, 130 (49.4%) thrombolyzed patients achieved an mRS score of 0-1 at 3 months. The female gender, age, and baseline NIHSS score were found to be significantly associated with CNI on univariate analysis. On multivariate analysis, NIHSS score at onset and female gender (odds ratio [OR]: 2.218, 95% confidence interval [CI]: 1.140-4.285; P=.024) were found to be independent predictors of CNI. Factors associated with favorable outcomes at 3 months on univariate analysis were younger age, female gender, hypertension, NIHSS score at onset, recanalization on transcranial Doppler (TCD) monitoring or repeat computed tomography (CT) angiography, ENI at 2 hours, and CNI. On multivariate analysis, NIHSS score at onset (OR per 1-point increase: .835, 95% CI: .751-.929, P<.001), 2-hour TCD recanalization (OR: 3.048, 95% CI: 1.537-6.046; P=.001), 24-hour CT angiographic recanalization (OR: 4.329, 95% CI: 2.382-9.974; P=.001), ENI at 2 hours (OR: 2.536, 95% CI: 1.321-5.102; P=.004), and CNI (OR: 7.253, 95% CI: 3.682-15.115; P<.001) were independent predictors of favorable outcomes at 3 months. CONCLUSIONS:Women are twice as likely to have CNI from the 2- to 24-hour period after IV tPA. ENI and CNI within the first 24 hours are strong predictors of favorable functional outcomes in thrombolyzed AIS patients.
Tandem internal carotid artery/middle cerebral artery occlusion: an independent predictor of poor outcome after systemic thrombolysis.
Rubiera Marta,Ribo Marc,Delgado-Mederos Raquel,Santamarina Esteban,Delgado Pilar,Montaner Joan,Alvarez-Sabín José,Molina Carlos A
BACKGROUND AND PURPOSE:Although tandem internal carotid artery/middle cerebral artery (MCA; TIM) occlusion has been associated with low recanalization rate after IV tissue plasminogen activator (tPA), its independent contribution on stroke outcome remains unknown. Moreover, whether the relative resistance to thrombolysis in tandem lesions varies depending on the location of MCA clot remains uncertain. METHODS:Two hundred and twenty-one consecutive stroke patients with an acute MCA occlusion treated with IV tPA were studied. Emergent carotid artery ultrasound and transcranial Doppler (TCD) examinations were performed in all patients before treatment. Recanalization was assessed on TCD at 2 hours of tPA bolus. National Institutes of Health Stroke Scale (NIHSS) scores were obtained at baseline and after 24 hours. Modifed Rankin Scale score was used to assess outcome at 3 months. RESULTS:Median prebolus NIHSS score was 16 points. On TCD, 156 (71.6%) patients had a proximal and 65 (29.4%) a distal MCA occlusion. TIM occlusion was identified in 44 (19.9%) patients. Eighteen (41.9%) patients with and 123 (69.5%) without TIM lesions achieved an MCA recanalization (P=0.01). In a logistic regression model, hyperglycemia >140 mg/dL (odds ratio [OR] 3.3, 95% CI, 1.6 to 6.8) and the presence of TIM occlusion (OR 2.8, 95% CI, 1.1 to 6.9) emerged as independent predictors of absence of recanalization. However, the independent contribution of TIM lesions on poor response to thrombolysis varied depending on the location of MCA occlusion. TIM occlusion independently predicted resistance to thrombolysis in patients with proximal (OR 4.63, 95% CI, 1.79 to 11.96), but not in those with distal MCA occlusion. Patients with TIM occlusion had worse short- (P<0.0001) and long-term (P<0.0001) clinical outcome. CONCLUSIONS:TIM occlusion independently predicts poor outcome after IV thrombolysis. However, its impact varies depending on the location of MCA clot. Therefore, emergent carotid ultrasound plus TCD examinations may improve the selection of patients for more aggressive reperfusion strategies.
Residual flow at the site of intracranial occlusion on transcranial Doppler predicts response to intravenous thrombolysis: a multi-center study.
Saqqur Maher,Tsivgoulis Georgios,Molina Carlos A,Demchuk Andrew M,Shuaib Ashfaq,Alexandrov Andrei V,
Cerebrovascular diseases (Basel, Switzerland)
BACKGROUND:We examined if transcranial Doppler (TCD) flow findings at the site of intracranial occlusions predict outcomes of stroke patients receiving intravenous rt-PA treatment. SUBJECTS AND METHODS:TCD detected residual flow with the Thrombolysis in Brain Ischemia (TIBI) grading system before intravenous rt-PA bolus in patients with acute arterial intracranial occlusion. Timing and completion of early recanalization were measured for occlusive TIBI flow grades using TCD monitoring. Poor responders were defined as modified Rankin scores (mRS) >2 at 3 months. RESULTS:A total of 361 patients with proximal arterial occlusion received intravenous rt-PA at 137.4 +/- 36 min (median NIHSS 16). Mean age 69 +/- 13, women: 168 (46.5%). Seventeen of 96 (17.7%) patients with TIBI 0, 41/124 (33.1%) with TIBI 1, 29/76 (38.2%) with TIBI 2 and 31/65 (47.7%) with TIBI 3 had achieved complete recanalization (p < 0.001). Higher NIHSS, SBP, glucose and lower TIBI grades were independent negative predictors of complete recanalization in the final logistic model. Patients with TIBI 0 had less probability of complete recanalization than patients with residual flow (TIBI 1-3) (OR(adj) 0.4, CI 95% 0.22-0.8, p = 0.008). Median time to recanalization in patients with TIBI 0 was longer (155 min, interquartile range 104-190 min) than with TIBI >or=1 (120 min, range 60-170 min, p = 0.01, Mann-Whitney U test). In the stepwise multiple linear regression models adjusting for baseline characteristics, the only 2 factors that independently associated with time to recanalization were: time to rt-PA treatment and the absent flow (TIBI 0) on baseline TCD. Absent flow (TIBI 0) was associated with a longer time of recanalization of 35.2 min (95% CI 0.3-70.1 min, p = 0.048). Poor outcomes at 3 months were found in 61.3% of patients with no residual flow (TIBI 0), 56.9% with minimal (TIBI 1), 51.5% with blunted (TIBI 2), and 33.9% with dampened (TIBI 3) flows (p = 0.012). Patients with TIBI 0 have a higher likelihood of poor outcome (OR 3.1, 95% CI 1.5-6.4, p = 0.002). Patients who achieved complete recanalization have OR(adj) 5.2 for good outcome (95% CI 2.8-9.8, p < 0.001). CONCLUSIONS:The pretreatment residual flow at intracranial occlusion predicts the likelihood of complete recanalization, time of recanalization and long-term outcome. No detectable residual flow indicates the least chance to achieve recanalization and recovery with systemic thrombolysis and may support an early decision for combined endovascular rescue.
The hemodynamic status within 24 h after intravenous thrombolysis predicts infarct growth in acute ischemic stroke.
Baizabal-Carvallo José Fidel,Rosso Charlotte,Alonso-Juarez Marlene,Pires Christine,Samson Yves
Journal of neurology
A rapid and complete recanalization of the occluded artery is the ideal goal when intravenous (IV) recombinant tissue plasminogen activator (rt-PA) is administrated to patients with acute ischemic stroke, i.e., limiting the ongoing ischemia to achieve a better outcome. We explored the effect of complete versus partial recanalization of the occluded intracranial artery after IV thrombolysis on the infarct growth and evaluated the functional impact. Using diffusion-weighted (DWI) volumetric measurements before rt-PA administration (DWI(1)) and 24 h later (DWI(2)), we calculated the infarct growth in 36 consecutive patients with ischemic stroke treated with IV rt-PA, with the formula DWI(2)/DWI(1). Recanalization of the affected artery was assessed by transcranial Doppler (TCD) and magnetic resonance angiography (MRA) within 24 h of stroke onset. Three patients were eliminated from the analysis; 33 patients were fully analyzed (men: n = 23; mean (SD) age: 72.4 ± 16 years; time from stroke onset to rt-PA: 179 ± 54 min; mean NIHSS score at admission: 17). Patients achieving full recanalization by TCD had a smaller infarct growth, compared to those who had a partial or persistent occlusion after thrombolysis: 1.86 versus 2.91 (P = 0.017). This difference was not significant using MRA criteria: 2.01 versus 2.69 (P = 0.193). In the regression analysis, complete recanalization by TCD was an independent predictor of infarct growth (P = 0.045). Thus, complete recanalization measured by TCD within 24 h of IV thrombolysis was independently associated with smaller infarct growth.
Clinical deterioration following middle cerebral artery hemodynamic changes after intravenous thrombolysis for acute ischemic stroke.
Baizabal-Carvallo José Fidel,Alonso-Juarez Marlene,Samson Yves
Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association
BACKGROUND:Little information exists regarding what occurs in the affected artery in the days after acute ischemic stroke and its impact in the outcome. We sought to determine the hemodynamic evolution and correlated this evoution with clinical outcome in stroke patients treated with intravenous thrombolysis. METHODS:Using serial transcranial Doppler ultrasound (TCD) on days 1 (TCD1), 3 to 6 (TCD2), and 7 to 10 (TCD3) after stroke, we determined the hemodynamics in the affected artery by means of the thrombolysis in brain ischemia (TIBI) score and compared this with clinical outcome (National Institutes of Health Stroke Scale [NIHSS] score) and functional outcome (modified Rankin Scale score) at discharge and at 3 months. RESULTS:Thirty-four patients were studied. There were 24 men with a mean (± SD) age of 72.9 ± 16.2 years. The mean time from stroke onset to the administration of intravenous tissue plasminogen activator was 181 ± 54.4 minutes, and the mean NIHSS score at admission was 16.9 ± 9. Hemodynamic changes were observed in 23 (68%) patients, including improvement in 17 (50%) patients and worsening in 6 (18%) patients within the first 10 days poststroke. Clinical deterioration (NIHSS ≥4 points) was timely associated with hemodynamic deterioration in 3 cases. Patients achieving full recanalization at TCD3 had better mRS scores at 3 months (4 v 3; P = .02). CONCLUSIONS:Hemodynamic changes in the affected artery occurred in about two-thirds of patients within the first 10 days after receiving intravenous thrombolysis; 18% had hemodynamic deterioration, which was associated with clinical worsening in half of these cases.
Timing of recanalization after tissue plasminogen activator therapy determined by transcranial doppler correlates with clinical recovery from ischemic stroke.
Christou I,Alexandrov A V,Burgin W S,Wojner A W,Felberg R A,Malkoff M,Grotta J C
BACKGROUND:The duration of cerebral blood flow impairment correlates with irreversibility of brain damage in animal models of cerebral ischemia. Our aim was to correlate clinical recovery from stroke with the timing of arterial recanalization after therapy with intravenous tissue plasminogen activator (tPA). METHODS:Patients with symptoms of cerebral ischemia were treated with 0.9 mg/kg tPA IV within 3 hours after stroke onset (standard protocol) or with 0.6 mg/kg at 3 to 6 hours (an experimental institutional review board-approved protocol). National Institutes of Health Stroke Scale (NIHSS) scores were obtained before treatment, at the end of tPA infusion, and at 24 hours; Rankin Scores were obtained at long-term follow-up. Transcranial Doppler (TCD) was used to locate arterial occlusion before tPA and to monitor recanalization (Marc head frame, Spencer Technologies; Multigon 500M, DWL MultiDop-T). Recanalization on TCD was determined according to previously developed criteria. RESULTS:Forty patients were studied (age 70+/-16 years, baseline NIHSS score 18.6+/-6.2). A tPA bolus was administered at 132+/-54 minutes from symptom onset. Recanalization on TCD was found at the mean time of 251+/-171 minutes after stroke onset: complete recanalization occurred in 12 (30%) patients and partial recanalization occurred in 16 (40%) patients (maximum observation time 360 minutes). Recanalization occurred within 60 minutes of tPA bolus in 75% of patients who recanalized. The timing of recanalization inversely correlated with early improvement in the NIHSS scores within the next hour (polynomial curve, third order r(2)=0.429, P<0.01) as well as at 24 hours. Complete recanalization was common in patients who had follow-up Rankin Scores if 0 to 1 (P=0.006). No patients had early complete recovery if an occlusion persisted for >300 minutes. CONCLUSIONS:The timing of arterial recanalization after tPA therapy as determined with TCD correlates with clinical recovery from stroke and demonstrates a 300-minute window to achieve early complete recovery. These data parallel findings in animal models of cerebral ischemia and confirm the relevance of these models in the prediction of response to reperfusion therapy.
Transcranial doppler ultrasound criteria for recanalization after thrombolysis for middle cerebral artery stroke.
Burgin W S,Malkoff M,Felberg R A,Demchuk A M,Christou I,Grotta J C,Alexandrov A V
BACKGROUND AND PURPOSE:Transcranial Doppler (TCD) can demonstrate arterial occlusion and subsequent recanalization in acute ischemic stroke patients treated with intravenous tissue plasminogen activator (tPA). Limited data exist to assess the accuracy of recanalization by TCD criteria. METHODS:In patients with acute middle cerebral artery (MCA) occlusion treated with intravenous tPA, we compared posttreatment TCD with angiography (digital subtraction or magnetic resonance). On TCD, complete occlusion was defined by absent or minimal signals, partial occlusion by blunted or dampened signals, and recanalization by normal or stenotic signals. Angiography was evaluated with the Thrombolysis In Myocardial Ischemia (TIMI) grading scale. RESULTS:Twenty-five patients were studied (age 61+/-18 years, 16 men and 9 women). TCD was performed at 12+/-16 hours and angiography at 41+/-57 hours after stroke onset, with 52% of studies performed within 3 hours of each other. Recanalization on TCD had the following accuracy parameters compared with angiography: sensitivity 91%, specificity 93%, positive predictive value (PPV) 91%, and negative predictive value (NPV) 93%. To predict partial occlusion (TIMI grade II), TCD had sensitivity of 100%, specificity of 76%, PPV of 44%, and NPV of 100%. TCD predicted the presence of complete occlusion on angiography (TIMI grade 0 or I) with sensitivity of 50%, specificity of 100%, PPV of 100%, and NPV of 75%. TCD flow signals correlated with angiographic patency (chi(2)=24.2, P<0.001). CONCLUSIONS:Complete MCA recanalization on TCD accurately predicts angiographic findings. Although a return to normal flow dynamics on TCD was associated with complete angiographic resumption of flow, partial signal improvement on TCD corresponded with persistent occlusion on angiography.
Safety and efficacy of ultrasound-enhanced thrombolysis in the treatment of acute middle cerebral artery infarction: a critically appraised topic.
Kramer Christopher,Aguilar Maria I,Hoffman-Snyder Charlene,Wellik Kay E,Wingerchuk Dean M,Demaerschalk Bart M
BACKGROUND:Despite appropriate therapy with intravenous (IV) tissue plasminogen activator (tPA), a significant proportion of patients with acute middle cerebral artery (MCA) infarction continue to suffer residual disability or death. The therapeutic use of transcranial Doppler ultrasonography (TCD) concomitantly with IV tPA is speculated to increase recanalization rates and improve clinical outcomes in patients with acute MCA stroke. OBJECTIVE:To critically appraise the evidence concerning the safety and efficacy of the simultaneous delivery of IV tPA and continuous TCD monitoring as an acute therapy in patients with MCA territory infarction. METHODS:The objective was addressed through the development of a structured, critically appraised topic. This incorporated a clinical scenario, background information, a structured question, literature search strategy, results, critical appraisal, clinical bottom line, and expert commentary from vascular neurology. RESULTS:In a multicenter phase II randomized controlled study, 126 patients with acute MCA stroke were randomized to receive treatment with IV tPA and continuous TCD monitoring or placebo monitoring. Complete recanalization or dramatic clinical recovery within 2 hours after the administration of a tPA bolus occurred in 31 patients in the target group (49%), as compared with 19 patients in the control group (30%); P=0.03. At 3 months, of the patients eligible for follow-up, 22 of 53 (42%) in the target group and 14 of 49 (29%) in the control group had favorable outcomes; P=0.20. Four symptomatic intracerebral hemorrhages were noted in each group. CONCLUSIONS:Therapeutic use of continuous TCD monitoring concomitantly with IV tPA increases recanalization rates in patients with acute MCA stroke relative to treatment with IV tPA alone without increasing the complication of intracerebral hemorrhage.
Recanalization after thrombolysis in stroke patients: predictors and prognostic implications.
Zangerle A,Kiechl S,Spiegel M,Furtner M,Knoflach M,Werner P,Mair A,Wille G,Schmidauer C,Gautsch K,Gotwald T,Felber S,Poewe W,Willeit J
OBJECTIVE:To estimate rates, predictors, and prognostic importance of recanalization in an unselected series of patients with stroke treated with IV thrombolysis. METHODS:We performed a CT angiography or transcranial Doppler (TCD) follow-up examination 24 hours after IV thrombolysis in 64 patients with documented occlusion of the intracranial internal carotid or middle cerebral artery (MCA). Complete recanalization was defined by a rating of 3 on the Thrombolysis in Myocardial Infarction or 4/5 on the Thrombolysis in Brain Ischemia grading scales. Information about risk factors, clinical features, and outcome was prospectively collected by standardized procedures. RESULTS:Complete recanalization was achieved in 36 of the 64 patients (56.3%). There was a nonsignificant trend of recanalization rates to decline with a more proximal site of occlusion: 68.4% (M2 segment of MCA), 53.1% (M1 segment), and 46.2% (carotid T) (p for trend = 0.28). Frequencies of vessel reopening were markedly reduced in subjects with diabetes (9.1% vs 66.0% in nondiabetics, p < 0.001) and less so in subjects with additional extracranial carotid occlusion (p = 0.03). Finally, complete recanalization predicted a favorable stroke outcome at day 90 independently of the information provided by age, NIH Stroke Scale, and onset-to-needle time. CONCLUSIONS:We found a high rate of vessel recanalization after IV thrombolysis occlusion. However, recanalization was infrequent in patients with diabetes and extracranial carotid occlusion. Information on recanalization was a powerful, early predictor for clinical outcome.
Residual flow signals predict complete recanalization in stroke patients treated with TPA.
Labiche Lise A,Malkoff Marc,Alexandrov Andrei V
Journal of neuroimaging : official journal of the American Society of Neuroimaging
BACKGROUND:Residual blood flow around thrombus prior to treatment predicts success of coronary thrombolysis. The authors aimed to correlate the presence of residual flow signals in the middle cerebral artery (MCA) with completeness of recanalization after intravenous tissue plasminogen activator (TPA). METHODS:The authors studied consecutive patients treated with intravenous TPA therapy who had a proximal MCA occlusion on pretreatment transcranial Doppler (TCD). Patients were continuously monitored for 2 hours after TPA bolus. Absent residual flow signals correspond to the thrombolysis in brain ischemia (TIBI) 0 grade, and the presence of residual flow signals was determined as TIBI 1-3 flow grades. Complete recanalization was defined as flow improvement to TIBI grades 4-5. RESULTS:Seventy-five patients with a proximal MCA occlusion had median pre-bolus NIHSS 16 (85% with > or = 10 points). TPA bolus was given at 141 +/- 56 minutes (median 120 minutes). Complete recanalization was observed in 25 (33%), partial in 23 (31%), and no early recanalization was seen in 27 (36%) patients within 2 hours after TPA bolus. Only 19% with absent residual flow signals (TIBI grade 0, n = 26) on pretreatment TCD had complete early recanalization. If pretreatment TCD showed the presence of any residual flow (TIBI 1-3, n = 49), 41% had complete recanalization within 2 hours of TPA bolus (P = .03). CONCLUSIONS:Patients with detectable residual flow signals before IV TPA bolus are twice as likely to have early complete recanalization. Those with no detectable residual flow signals have less than 20% chance for complete early recanalization with intravenous TPA and may be candidates for intra-arterial therapies.
[TCD monitoring during intravenous administration of recombinant tissue plasminogen activator].
Aoki Junya,Iguchi Yasuyuki,Kobayashi Kazuto,Sakai Kenichiro,Shibazaki Kensaku,Sakamoto Yuki,Kimura Kazumi
Rinsho shinkeigaku = Clinical neurology
Our aim is to investigate the utility of transcranial Doppler (TCD) monitoring during intravenous administration of 0.6 mg/kg recombinant tissue plasminogen activator (IV rt-PA) which is governmental approved in Japan. Acute ischemic stroke patients with M1 portion of the middle cerebral artery (M1) occlusion treated with IV rt-PA were prospectively enrolled. M1 occlusion was diagnosed before IV rt-PA using magnetic resonance angiography (MRA). Patients without sufficient temporal window of TCD were excluded. TCD monitoring was conducted for 1 hour (h) during IV rt-PA. Recanalization on TCD was defined using thrombolysis in brain ischemia (TIBI) flow grades. After all patients were classified into two groups according to the presence of TCD recanalization (TCD recanalization and TCD non-recanalization group), three-month patients outcome, recanalization rate on MRA 1 h of IV rt-PA, and symptomatic cerebral hemorrhage within 24 h were compared between two groups. We enrolled 16 patients. Eight patients (50%, 7 men [88%]; age, 70 years [interquartile range. 55-81]; NIHSS score, 18 [12-22]) were in the TCD recanalization group and 8 (50%, 6 men [75%]; age, 72 years [62-79]; NIHSS score 19 [15-23] were in the TCD non-recanalization group. Symptomatic cerebral hemorrhage was not seen in both groups at all. MRA 1 h of IV rt-PA revealed recanalization in all 8 (100%) patients with TCD recanalization group and 2 (25%) with TCD non-recanalization group (agreement, 88%; and kappa value, 0.75, P = 0.002). At three months, 5 (63%) of 8 patients in the TCD recanalization group had favorable outcome, and 0 (0%) of 8 in the TCD non-recanalization group (P = 0.026). TCD monitoring for 1 h during IV rt-PA can diagnose the recanalization based on MRA. TCD monitoring should predict good clinical outcome at three months.
Cerebral Hemodynamic Evaluation After Cerebral Recanalization Therapy for Acute Ischemic Stroke.
Zhang Zhe,Pu Yuehua,Mi Donghua,Liu Liping
Frontiers in neurology
Cerebral recanalization therapy, either intravenous thrombolysis or mechanical thrombectomy, improves the outcomes in patients with acute ischemic stroke (AIS) by restoring the cerebral perfusion of the ischemic penumbra. Cerebral hemodynamic evaluation after recanalization therapy, can help identify patients with high risks of reperfusion-associated complications. Among the various hemodynamic modalities, magnetic resonance imaging (MRI), computed tomography perfusion, and transcranial Doppler sonography (TCD) are the most commonly used. Poststroke hypoperfusion is associated with infarct expansion, while hyperperfusion, which once was considered the hallmark of successful recanalization, is associated with hemorrhagic transformation. Either the hypo- or the hyperperfusion may result in poor clinical outcomes. Individual blood pressure target based on cerebral hemodynamic evaluation was crucial to improve the prognosis. This review summarizes literature on cerebral hemodynamic evaluation and management after recanalization therapy to guide clinical decision making.
Relationship Between Brain Pulsatility and Cerebral Perfusion Pressure: Replicated Validation Using Different Drivers of CPP Change.
Calviello Leanne A,de Riva Nicolás,Donnelly Joseph,Czosnyka Marek,Smielewski Peter,Menon David K,Zeiler Frederick A
BACKGROUND:Determination of relationships between transcranial Doppler (TCD)-based spectral pulsatility index (sPI) and pulse amplitude (AMP) of intracranial pressure (ICP) in 2 groups of severe traumatic brain injury (TBI) patients (a) displaying plateau waves and (b) with unstable mean arterial pressure (MAP). METHODS:We retrospectively reviewed patients with severe TBI and continuous TCD monitoring displaying either plateau waves or unstable MAP from 1992 to 1998. We utilized linear and nonlinear regression techniques to describe both cohorts: cerebral perfusion pressure (CPP) versus AMP, CPP versus sPI, mean ICP versus ICP AMP, mean ICP versus sPI, and AMP versus sPI. RESULTS:Nonlinear regression techniques were employed to analyze the relationships with CPP. In plateau wave and unstable MAP patients, CPP versus sPI displayed an inverse nonlinear relationship (R = 0.820 vs. R = 0.610, respectively), with the CPP versus sPI relationship best modeled by the following function in both cases: PI = a + (b/CPP). Similarly, in both groups, CPP versus AMP displayed an inverse nonlinear relationship (R = 0.610 vs. R = 0.360, respectively). Positive linear correlations were displayed in both the plateau wave and unstable MAP cohorts between: ICP versus AMP, ICP versus sPI, AMP versus sPI. CONCLUSIONS:There is an inverse relationship through nonlinear regression between CPP versus AMP and CPP versus sPI display. This provides evidence to support a previously-proposed model of TCD pulsatility index. ICP shows a positive linear correlation with AMP and sPI, which is also established between AMP and sPI.
Cerebrovascular Hemodynamics on Transcranial Doppler Ultrasonography and Cognitive Decline in Mild Cognitive Impairment.
Lim Eun-Ye,Yang Dong-Won,Cho A-Hyun,Shim Yong S
Journal of Alzheimer's disease : JAD
BACKGROUND/OBJECTIVE:Vascular risk factors and neurovascular dysfunction may be closely related to cognitive impairment and dementia. In this study, we evaluated the association between hemodynamic markers and longitudinal cognitive changes in patients with mild cognitive impairment (MCI). Furthermore, we investigated whether hemodynamic markers could predict the risk of progression to Alzheimer's disease (AD) in patients with MCI. METHODS:A total of 68 subjects with amnestic MCI were recruited. Using transcranial Doppler (TCD) ultrasonography, cerebrovascular reactivity was evaluated with a breath-holding test (breath holding index; BHI) in addition to the mean flow velocity (MFV) and pulsatility index (PI) of the middle cerebral artery. We followed subjects for 24 months and each subject underwent neuropsychological testing and TCD ultrasonography, annually. According to the follow-up neuropsychological studies and clinical interviews at 12 months, we divided the patients with MCI into two groups: patients with stable cognitive performance and patients who progressed to AD. RESULTS:Lower BHI and higher PI were observed in patients who progressed to AD. The changes of MMSE score over the first 12 months correlated with lower baseline MMSE score and changes of MFV and BHI. The changes of MMSE score over 24 months were closely related to higher baseline resistance index and PI values. Multivariate logistic regression showed that abnormal baseline BHI value could predict a conversion from MCI to AD. CONCLUSIONS:We confirmed there is a close association between hemodynamic changes represented by TCD markers and cognitive decline, supporting the clinical value of hemodynamic markers in predicting MCI patients who will progress to AD.
Transcranial Doppler in autonomic testing: standards and clinical applications.
Norcliffe-Kaufmann Lucy,Galindo-Mendez Brahyan,Garcia-Guarniz Ana-Lucia,Villarreal-Vitorica Estibaliz,Novak Vera
Clinical autonomic research : official journal of the Clinical Autonomic Research Society
When cerebral blood flow falls below a critical limit, syncope occurs and, if prolonged, ischemia leads to neuronal death. The cerebral circulation has its own complex finely tuned autoregulatory mechanisms to ensure blood supply to the brain can meet the high metabolic demands of the underlying neuronal tissue. This involves the interplay between myogenic and metabolic mechanisms, input from noradrenergic and cholinergic neurons, and the release of vasoactive substrates, including adenosine from astrocytes and nitric oxide from the endothelium. Transcranial Doppler (TCD) is a non-invasive technique that provides real-time measurements of cerebral blood flow velocity. TCD can be very useful in the work-up of a patient with recurrent syncope. Cerebral autoregulatory mechanisms help defend the brain against hypoperfusion when perfusion pressure falls on standing. Syncope occurs when hypotension is severe, and susceptibility increases with hyperventilation, hypocapnia, and cerebral vasoconstriction. Here we review clinical standards for the acquisition and analysis of TCD signals in the autonomic laboratory and the multiple methods available to assess cerebral autoregulation. We also describe the control of cerebral blood flow in autonomic disorders and functional syndromes.
Detection of reversed basilar flow with power-motion Doppler after acute occlusion predicts favorable outcome.
Ribo Marc,Garami Zsolt,Uchino Ken,Song Joon,Molina Carlos A,Alexandrov Andrei V
BACKGROUND AND PURPOSE:Power-motion transcranial Doppler PMD-TCD is a new method for simultaneous display of flow at multiple depths. We aimed to determine clinical significance of PMD-TCD demonstration of reversed basilar flow in patients with basilar artery (BA) occlusion. METHODS:We prospectively evaluated patients with acute vertebrobasilar ischemia using PMD-TCD. Using a predefined set of TCD depth criteria and specific flow findings, occlusion was localized to the proximal, middle, or distal BA stem. The National Institutes of Health Stroke Scale was used to measure stroke severity and the modified Rankin Scale (mRS) to assess outcome at 3 months. RESULTS:BA occlusion was diagnosed in 16 patients (3 women, mean age 65, median NIHSS 8, mean time from symptoms onset 8.5 hours). PMD-TCD diagnosis of BA occlusion was confirmed in 11 of 12 patients who underwent invasive angiography. Reversed BA flow on PMD-TCD was identified in 8 patients (50%). Angiography confirmed flow from carotid system in 6 of these 8 patients (kappa=0.87). Patients with reversed BA flow showed lower NIHSS scores on admission (median 4 versus 15.5, P=0.009), on discharge (2 versus 21.5, P=0.03) and did not experience neurological deterioration during hospital stay (n=0 versus 4, P=0.05). There was a trend toward better outcome at 3 months (mRS 1 versus 4, P=0.07). CONCLUSIONS:Detection of reversed flow in the distal BA with PMD-TCD is associated with lower stroke severity and better outcome after acute basilar artery occlusion.
Role of transcranial Doppler in cerebral hyperperfusion syndrome.
Pennekamp C W A,Moll F L,De Borst G J
The Journal of cardiovascular surgery
The benefit of carotid revascularization is hampered by occurrence of periprocedural cerebrovascular complications. Cerebral hyperperfusion syndrome (CHS) is a potentially life threatening complication occurring in approximately 3% of all patients following either carotid endarterectomy (CEA) or carotid angioplasty with stenting (CAS). CHS generally is defined as a transcranial Doppler (TCD) derived increase in cerebral blood flow of >100% over baseline. To reduce related morbidity and mortality early identification of patients at risk is essential. As such, TCD offers a technique for cerebral blood flow measurement that is nowadays the only applied and useful clinical monitoring tool for CHS prediction. Several studies have assessed the diagnostic value of TCD in the prediction of CHS and found promising results. However, results were based on a small number of cases and different definitions have been used to diagnose CHS. Moreover, the role of TCD in the onset of CHS has been studied most extensively following CEA, and it is unclear whether the findings of these studies can be generalized to patients undergoing CAS. Therefore we conclude that further studies in larger cohorts are required to assess the changes in cerebral hemodynamic in patients undergoing either CAS or CEA.
Estimating Pressure Reactivity Using Noninvasive Doppler-Based Systolic Flow Index.
Zeiler Frederick A,Smielewski Peter,Donnelly Joseph,Czosnyka Marek,Menon David K,Ercole Ari
Journal of neurotrauma
The study objective was to derive models that estimate the pressure reactivity index (PRx) using the noninvasive transcranial Doppler (TCD) based systolic flow index (Sx_a) and mean flow index (Mx_a), both based on mean arterial pressure, in traumatic brain injury (TBI). Using a retrospective database of 347 patients with TBI with intracranial pressure and TCD time series recordings, we derived PRx, Sx_a, and Mx_a. We first derived the autocorrelative structure of PRx based on: (A) autoregressive integrative moving average (ARIMA) modeling in representative patients, and (B) within sequential linear mixed effects (LME) models with various embedded ARIMA error structures for PRx for the entire population. Finally, we performed sequential LME models with embedded PRx ARIMA modeling to find the best model for estimating PRx using Sx_a and Mx_a. Model adequacy was assessed via normally distributed residual density. Model superiority was assessed via Akaike Information Criterion (AIC), Bayesian Information Criterion (BIC), log likelihood (LL), and analysis of variance testing between models. The most appropriate ARIMA structure for PRx in this population was (2,0,2). This was applied in sequential LME modeling. Two models were superior (employing random effects in the independent variables and intercept): (A) PRx ∼ Sx_a, and (B) PRx ∼ Sx_a + Mx_a. Correlation between observed and estimated PRx with these two models was: (A) 0.794 (p < 0.0001, 95% confidence interval (CI) = 0.788-0.799), and (B) 0.814 (p < 0.0001, 95% CI = 0.809-0.819), with acceptable agreement on Bland-Altman analysis. Through using linear mixed effects modeling and accounting for the ARIMA structure of PRx, one can estimate PRx using noninvasive TCD-based indices. We have described our first attempts at such modeling and PRx estimation, establishing the strong link between two aspects of cerebral autoregulation: measures of cerebral blood flow and those of pulsatile cerebral blood volume. Further work is required to validate.
Cerebral monitors versus regional anesthesia to detect cerebral ischemia in patients undergoing carotid endarterectomy: a meta-analysis.
Guay Joanne,Kopp Sandra
Canadian journal of anaesthesia = Journal canadien d'anesthesie
PURPOSE:The aim of this meta-analysis is to compare the ability of different types of brain monitoring systems vs clinical monitoring of the brain function to detect cerebral ischemia during cross-clamping of the carotid artery under regional anesthesia. METHODS:In May 2012, a search was conducted in PubMed, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Ovid MEDLINE for prospective trials with 20 patients or more where a cerebral monitoring system was compared with clinical brain monitoring during a carotid endarterectomy performed under regional anesthesia. The quality of the study was evaluated with the Cochrane Collaboration's tool. Data were extracted independently by the two investigators. RESULTS:Data could be extracted for 4,664 measurements taken from 29 studies: transcranial Doppler (TCD) = 739; cerebral saturation = 320; stump pressure = 2,549; electroencephalography (EEG) = 742; evoked potentials = 187; jugular venous saturation = 79; and jugular venous lactate = 48. The pooled diagnostic odds ratios (DOR) and 95% confidence intervals (CI) were obtained for EEG, TCD, stump pressure, evoked potentials, and cerebral saturation: (DOR 65.3; 95% CI 20.5 to 207.7; I(2) [56.8%]); (DOR 58.1; 95% CI 23.0 to 146.3; I(2) [24.9%]); (DOR 27.8; 95% CI 13.4 to 57.9; I(2) [59.9]); (DOR 17.2; 95% CI 2.4 to 123.9 I(2) [69.1]); and (DOR 12.1; 95% CI 3.5 to 41.2; I(2) [30.8]), respectively. Sequential testing with stump pressure 25 mmHg followed by either TCD or EEG delivered the best post-test probabilities. For EEG, the DOR increases with the number of channels used (P = 0.03). CONCLUSION:A combination of stump pressure and either TCD or EEG appears to deliver the best results for detecting brain ischemia during carotid artery cross-clamping. Electroencephalography should be used with a high number of channels.
Impact of external carotid artery occlusion at declamping of the external and common carotid arteries during carotid endarterectomy on development of new postoperative ischemic cerebral lesions.
Kobayashi Masakazu,Yoshida Kenji,Kojima Daigo,Oshida Sotaro,Fujiwara Shunrou,Kubo Yoshitada,Ogasawara Kuniaki
Journal of vascular surgery
OBJECTIVE:The external carotid artery (ECA) is inadvertently occluded during carotid endarterectomy (CEA). The importance of ECA occlusion has been emphasized as a loss of extracranial to intracranial collaterals, a source of chronic embolization, or a site for extended thrombosis during wound closure. This study aimed to determine whether ECA occlusion that inadvertently developed during endarterectomy and that was eventually detected using blood flow measurement of the ECA after declamping of all carotid arteries is a risk factor for development of new postoperative ischemic lesions at declamping of the ECA and common carotid artery (CCA) while clamping the internal carotid artery (ICA). This study also aimed to determine whether intraoperative transcranial Doppler (TCD) monitoring predicts the risk for development of such lesions. METHODS:This was a prospective observational study that included patients undergoing CEA for severe stenosis (≥70%) of the cervical ICA. When blood flow through the ECA measured using an electromagnetic flow meter decreased rapidly on clamping of only the ECA before carotid clamping for endarterectomy and was not changed by clamping of only the ECA after carotid declamping following endarterectomy, the patient was determined to have developed ECA occlusion. These patients underwent additional endarterectomy for the ECA. TCD monitoring in the ipsilateral middle cerebral artery was also performed throughout surgery to identify microembolic signals (MESs). Brain magnetic resonance diffusion-weighted imaging (DWI) was performed before and after surgery. RESULTS:There were 104 patients enrolled in the study. Eight patients developed ECA occlusion during surgery. The incidence of intraoperative ECA occlusion was significantly higher in patients without MESs at the phase of ECA and CCA declamping (8/12 [67%]) than in those with MESs (0/92 [0%]; P < .0001). Six patients exhibited new postoperative ischemic lesions on DWI. The incidence of intraoperative ECA occlusion (P < .0001) and the absence of MESs at declamping of the ECA and CCA while clamping the ICA (P <. 0001) were significantly higher in patients with development of new postoperative ischemic lesions on DWI than in those without. Sensitivity and specificity for the absence of MESs at declamping of the ECA and CCA while clamping the ICA for predicting development of new postoperative ischemic lesions on DWI were 100% (6/6) and 94% (92/98), respectively. CONCLUSIONS:ECA occlusion at declamping of the ECA and CCA while clamping the ICA during CEA is a risk factor for development of new postoperative ischemic lesions. Intraoperative TCD monitoring accurately predicts the risk for development of such lesions.
Defining vasospasm after subarachnoid hemorrhage: what is the most clinically relevant definition?
Frontera Jennifer A,Fernandez Andres,Schmidt J Michael,Claassen Jan,Wartenberg Katja E,Badjatia Neeraj,Connolly E Sander,Mayer Stephan A
BACKGROUND AND PURPOSE:Vasospasm is an important complication of subarachnoid hemorrhage, but is variably defined in the literature. METHODS:We studied 580 patients with subarachnoid hemorrhage and identified those with: (1) symptomatic vasospasm, defined as clinical deterioration deemed secondary to vasospasm after other causes were eliminated; (2) delayed cerebral ischemia (DCI), defined as symptomatic vasospasm, or infarction on CT attributable to vasospasm; (3) angiographic spasm, as seen on digital subtraction angiography; and (4) transcranial Doppler (TCD) spasm, defined as any mean flow velocity >120 cm/sec. Logistic regression analysis was performed to test the association of each definition of vasospasm with various hospital complications, and 3-month quality of life (sickness impact profile), cognitive status (telephone interview of cognitive status), instrumental activities of daily living (Lawton score), and death or severe disability at 3 months (modified Rankin scale score 4-6), after adjustment for covariates. RESULTS:Symptomatic vasospasm occurred in 16%, DCI in 21%, angiographic vasospasm in 31%, and TCD spasm in 45% of patients. DCI was statistically associated with more hospital complications (N=7; all P<0.05) than symptomatic spasm (N=4), angiographic spasm (N=1), or TCD vasospasm (N=1). Angiographic and TCD vasospasm were not related to any aspect of clinical outcome. Both symptomatic vasospasm and DCI were related to reduced instrumental activities of daily living, cognitive impairment, and poor quality of life (all P<0.05). However, only DCI was associated with death or severe disability at 3 months (adjusted OR, 2.2; 95% CI, 1.2-3.9; P=0.007). CONCLUSIONS:DCI is a more clinically meaningful definition than either symptomatic deterioration alone or the presence of arterial spasm by angiography or TCD.
Post-carotid endarterectomy cerebral hyperperfusion syndrome : is it preventable by strict blood pressure control?
Kim Kyung Hyun,Lee Chang-Hyun,Son Young-Je,Yang Hee-Jin,Chung Young Sub,Lee Sang Hyung
Journal of Korean Neurosurgical Society
OBJECTIVE:Cerebral hyperperfusion syndrome (CHS) is a serious complication after carotid endarterectomy (CEA). However, the prevalence of CHS has decreased as techniques have improved. This study evaluates the role of strict blood pressure (BP) control for the prevention of CHS. METHODS:All 18 patients who received CEA from February 2009 through November 2012 were retrospectively reviewed. All patients were routinely managed in an intensive care unit by a same protocol. The cerebral perfusion state was evaluated on the basis of the regional cerebral blood flow (rCBF) study by perfusion computed tomography (pCT) and mean velocity by transcranial doppler (TCD). BP was strictly controlled (<140/90 mm Hg) for 7 days. When either post-CEA hyperperfusion (>100% increase in the rCBF by pCT or in the mean velocity by TCD compared with preoperative values) or CHS was detected, BP was maintained below 120/80 mm Hg. RESULTS:TCD and pCT data on the patients were analyzed. Ipsilateral rCBF was significantly increased after CEA in the pCT (p=0.049). Post-CEA hyperperfusion was observed in 3 patients (18.7%) in the pCT and 2 patients (12.5%) in the TCD study. No patients developed clinical CHS for one month after CEA. Furthermore, no patients developed additional neurological deficits related to postoperative cerebrovascular complications. CONCLUSION:Intensive care with strict BP control (<140/90 mm Hg) achieved a low prevalence of post-CEA hyperperfusion and prevented CHS. This study suggests that intensive care with strict BP control can prevent the prevalence of post-CEA CHS.
Significance of C-reactive protein and transcranial Doppler in cerebral vasospasm following aneurysmal subarachnoid hemorrhage.
Hwang Sung-Hwan,Park Yong-Sook,Kwon Jeong-Taik,Nam Taek-Kyun,Hwang Sung-Nam,Kang Hyun
Journal of Korean Neurosurgical Society
OBJECTIVE:Cerebral vasospasm is a common and potentially devastating complication of aneurysmal subarachnoid hemorrhage (aSAH). Inflammatory processes seem to play a major role in the pathogenesis of vasospasm. C-reactive protein (CRP) constitutes a highly sensitive inflammatory marker. Elevation of serum CRP levels has been demonstrated in patients with aSAH. The purpose of the current study was to evaluate the possible relationship between CRP levels in the serum and transcranial Doppler (TCD) and the development of vasospasm in patients with aSAH. METHODS:A total of 61 adult patients in whom aSAH was diagnosed were included in the study from November 2008 to May 2011. The patients' demographics, Hunt and Hess grade, Fisher grade, CT scans, digital subtraction angiography studies, and daily neurological examinations were recorded. Serial serum CRP measurements were obtained on days 1, 3, 5, 7, 9, 11 and 13 and TCD was measured on days 3, 5, 7, 9, 11 and 13. All patients underwent either surgical or endovascular treatment within 24 hours of their hemorrhagic attacks. RESULTS:Serum CRP levels peaked on the 3rd postoperative day. There were significant differences between the vasospasm group and the non-vasospasm group on the 1st, 3rd and 5th day. There were significant differences between the vasospasm group and the non-vasospasm group on the 3rd day in the mean middle cerebral artery velocities on TCD. CONCLUSION:Patients with high levels of CRP on the 1st postoperative day and high velocity of mean TCD on the 3rd postoperative day may require closer observation to monitor for the development of vasospasm.
Noninvasive Intracranial Pressure Estimation With Transcranial Doppler: A Prospective Observational Study.
Cardim Danilo,Robba Chiara,Czosnyka Marek,Savo Davide,Mazeraud Aurelién,Iaquaniello Carolina,Banzato Erika,Rebora Paola,Citerio Giuseppe
Journal of neurosurgical anesthesiology
BACKGROUND:Transcranial Doppler (TCD) ultrasonography has been described for the noninvasive assessment of intracranial pressure (ICP). This study investigates the relationship between standard, invasive intracranial pressure monitoring (ICPi) and noninvasive ICP assessment using a simple formula based on TCD-derived flow velocity (FV) and mean arterial blood pressure values (ICPTCD). MATERIAL AND METHODS:We performed a prospective observational study on 100 consecutive traumatic brain injury patients requiring invasive ICP monitoring, admitted to the Neurosciences and Trauma Critical Care Unit of Addenbrooke's Hospital, Cambridge, UK. ICPi was compared with ICPTCD using a method based on the "diastolic velocity-derived estimator" (FVd), which was initially described for the noninvasive estimation of cerebral perfusion pressure but subsequently utilized for ICP assessment. RESULTS:Median ICPi was 13 mm Hg (interquartile range: 10, 17.25 mm Hg). There was no correlation between ICPi and ICPTCD (R=-0.17; 95% confidence interval [CI]: -0.35, 0.03; P=0.097). Bland-Altman analysis demonstrated wide 95% limits of agreement between ICPi and ICPTCD (-27.58, 30.10; SD, 14.42). ICPTCD was not able to detect intracranial hypertension (ICPi >20 mm Hg); the area under the receiver operating characteristic curve for prediction was 34.5% (95% CI, 23.1%-45.9%) with 0% sensitivity and 74.4% specificity for ICPTCD to detect ICPi>20 mm Hg. CONCLUSIONS:Using a formula based on diastolic FV, TCD is an insufficiently accurate method for the noninvasive assessment of ICP. Further studies are warranted to confirm these results in a broader patient cohort.
Cerebral Hemodynamic Variations in the Early Stage after Carotid Artery Stenting in Patients with and without Near Occlusion.
Yan Ziguang,Yang Min,Niu Guochen,Zhang Bihui,Tong Xiaoqiang,Zou Yinghua
Annals of vascular surgery
BACKGROUND:To evaluate the unclear cerebral hemodynamic variations in patients with and without near occlusion (NO) in hours after carotid artery stenting (CAS) by transcranial Doppler (TCD). METHODS:Data of 56 patients (11 patients with carotid artery NO and 45 patients with severe stenosis without NO) who underwent unilateral CAS were analyzed. All patients underwent TCD or transcranial color-code Doppler monitoring before CAS and again at one and three hours after the procedure. We compared bilateral middle cerebral artery peak systolic velocity (MCA-PSV), pulsatility index (PI), and blood pressure (BP) data between the two groups. RESULTS:Ipsilateral MCA-PSV increased relative to baseline in the stenosis group at one hour (97 ± 30 vs. 84 ± 23 cm/s, 16%, P < 0.001) and three hours (96 ± 28 vs. 84 ± 23 cm/s, 15%, P < 0.001) after CAS. Corresponding increases were distinctly higher in the NO group than in the stenosis group at one hour (116 ± 37 vs. 80 ± 29 cm/s, 51%, P < 0.001) and three hours (113 ± 39 vs. 80 ± 29 cm/s, 46%, P = 0.001) after CAS, whereas BP decreased similarly between the two groups. The ipsilateral PI increased postsurgically in both groups, whereas contralateral MCA-PSV was unaltered. CONCLUSIONS:CAS can induce a significant increase in PSV and PI in ipsilateral MCA within three hours in patients with NO or severe stenosis but absent NO. The increment of ipsilateral MCA-PSV was greater in patients with NO. TCD can facilitate BP control in the early stage after CAS in patients with NO.
Early Transcranial Doppler Evaluation of Cerebral Autoregulation Independently Predicts Functional Outcome After Aneurysmal Subarachnoid Hemorrhage.
Rynkowski Carla B,de Oliveira Manoel Airton Leonardo,Dos Reis Marcelo Martins,Puppo Corina,Worm Paulo Valdeci,Zambonin Diego,Bianchin Marino Muxfeldt
BACKGROUND:Cerebral autoregulation (CA) impairment after aneurysmal subarachnoid hemorrhage (SAH) has been associated with delayed cerebral ischemia and an unfavorable outcome. We investigated whether the early transient hyperemic response test (THRT), a transcranial Doppler (TCD)-based CA evaluation method, can predict functional outcome 6 months after aneurysmal SAH. METHODS:This is a prospective observational study of all aneurysmal SAH patients consecutively admitted to a single center between January 2016 and February 2017. CA was evaluated within 72 h of hemorrhage by THRT, which describes the changes in cerebral blood flow velocity after a brief compression of the ipsilateral common carotid artery. CA was considered to be preserved when an increase ≥ 9% of baseline systolic velocity was present. According to the modified Rankin Scale (mRS: 4-6), the primary outcome was unfavorable 6 months after hemorrhage. Secondary outcomes included cerebral infarction, vasospasm on TCD, and an unfavorable outcome at hospital discharge. RESULTS:Forty patients were included (mean age = 54 ± 12 years, 70% females). CA was impaired in 19 patients (47.5%) and preserved in 21 (52.5%). Impaired CA patients were older (59 ± 13 vs. 50 ± 9, p = 0.012), showed worse neurological conditions (Hunt&Hess 4 or 5-47.4% vs. 9.5%, p = 0.012), and clinical initial condition (APACHE II physiological score-12 [5.57-13] vs. 3.5 [3-5], p = 0.001). Fourteen patients in the impaired CA group and one patient in the preserved CA group progressed to an unfavorable outcome (73.7% vs. 4.7%, p = 0.0001). The impaired CA group more frequently developed cerebral infarction than the preserved CA group (36.8% vs. 0%, p = 0.003, respectively). After multivariate analysis, impaired CA (OR 5.15 95% CI 1.43-51.99, p = 0.033) and the APACHE II physiological score (OR 1.67, 95% CI 1.01-2.76, p = 0.046) were independently associated with an unfavorable outcome. CONCLUSIONS:Early CA impairment detected by TCD and admission APACHE II physiological score independently predicted an unfavorable outcome after SAH.
Computed tomography and transcranial Doppler findings in acute and subacute phases of intracerebral hemorrhagic stroke.
Fülesdi Béla,Réka Kovács Katalin,Bereczki Dániel,Bágyi Péter,Fekete István,Csiba László
Journal of neuroimaging : official journal of the American Society of Neuroimaging
BACKGROUND AND PURPOSE:The hematoma volume is an important determinant of outcome and a predictor of clinical deterioration in patients with intracerebral hemorrhage (ICH). Our goal was to evaluate alterations in the cerebral circulation, in respect to hemorrhage and edema volume changes, using transcranial Doppler (TCD). METHODS:Twenty patients with acute supratentorial ICH were examined. Brain, hematoma, and edema volumes were calculated from CT scans performed at admission and 2 weeks later. Data were compared with those obtained from bilateral TCD recordings of the middle cerebral arteries. RESULTS:During TCD examination, blood flow velocities did not change, cerebral perfusion pressure (CPP) and resistance area product (RAP) decreased (P = .006, P = .002) while cerebral blood flow index (CBFI) remained constant on the affected side. Although hemorrhage volume did not correlate with RAP in the acute phase, correlation was found in the subacute phase (r = -.44, P = .04). CONCLUSIONS:TCD monitoring sensitively demonstrates the hemodynamic change caused by ICH but the severity of the changes does not correlate with the volume of the ICH in acute stage. The CPP, RAP, and CBFI values are more sensitive parameters than the absolute velocity values, therefore they contribute more to the understanding of hemodynamic changes developed after spontaneous ICH.
How to use cerebral ultrasound in the ICU.
Bertuetti Rita,Gritti Paolo,Pelosi Paolo,Robba Chiara
Cerebral ultrasound is a developing point of care tool for intensivists and emergency physicians, with an important role in the diagnosis of acute intracranial pathology, such as the assessment of cerebrovascular diseases and in the noninvasive intracranial pressure measurement both in the acute clinical settings and in intensive care unit (ICU). The traditional application of transcranial doppler (TCD) by assessing blood flow velocities in the main cerebral arteries, allows the evaluation and follow up of cerebral vasospasm, cerebral perfusion pressure, cerebral autoregulation and intracranial hypertension. The use of TCD, traditionally limited to the neurosonology laboratories settings, has expanded over the last years following the introduction of B-mode ultrasound and color Doppler, the transcranial color-coded duplex ultrasonography (TCCS), opening a new window to the assessment of cerebral anatomy not only in the neurocritical patients, but also in general ICU and emergency room patients. Here we report a brief review with the intent to up-to-date and describe the main applications and use of TCD/TCCS in the setting of Neurointensive Care.
Monitoring of cerebral blood flow and ischemia in the critically ill.
Miller Chad,Armonda Rocco,
Secondary ischemic injury is common after acute brain injury and can be evaluated with the use of neuromonitoring devices. This manuscript provides guidelines for the use of devices to monitor cerebral blood flow (CBF) in critically ill patients. A Medline search was conducted to address essential pre-specified questions related to the utility of CBF monitoring. Peer-reviewed recommendations were constructed according to the GRADE criteria based upon the available supporting literature. Transcranial Doppler ultrasonography (TCD) and transcranial color-coded duplex sonography (TCCS) are predictive of angiographic vasospasm and delayed ischemic neurological deficits after aneurysmal subarachnoid hemorrhage. TCD and TCCS may be beneficial in identifying vasospasm after traumatic brain injury. TCD and TCCS have shortcomings in identifying some secondary ischemic risks. Implantable thermal diffusion flowmetry (TDF) probes may provide real-time continuous quantitative assessment of ischemic risks. Data are lacking regarding ischemic thresholds for TDF or their correlation with ischemic injury and clinical outcomes.TCD and TCCS can be used to monitor CBF in the neurocritical care unit. Better and more developed methods of continuous CBF monitoring are needed to limit secondary ischemic injury in the neurocritical care unit.
Transcranial Doppler Ultrasound in the Current Era of Carotid Artery Stenting.
Spacek M,Sorrell V L,Veselka J
Ultraschall in der Medizin (Stuttgart, Germany : 1980)
Since its introduction in 1982, transcranial Doppler ultrasound (TCD) has become an important diagnostic and monitoring tool and its usefulness has been well established in many clinical applications. In carotid artery stenting (CAS), TCD has mostly been reserved for the optimization of emboli protection devices. Currently, with increasing use of proximal protection systems resembling surgical clamps, TCD has become invaluable in providing the operator an insight into a patient's cerebral hemodynamic status. Additionally, in selected patients, adverse peri- or post-procedural cerebral outcomes may even be predicted allowing the operator to adjust the therapeutic strategy. This review summarizes the current knowledge regarding the use of TCD in patients undergoing CAS and suggests potential directions of future research.
Brain natriuretic peptide and cerebral vasospasm in subarachnoid hemorrhage. Clinical and TCD correlations.
Sviri G E,Feinsod M,Soustiel J F
BACKGROUND AND PURPOSE:Hyponatremia has been shown in association with cerebral vasospasm (CVS) following aneurysmal subarachnoid hemorrhage (SAH). In the past few years there has been increasing evidence that brain natriuretic peptide (BNP) is responsible for natriuresis after SAH. The purpose of the present study was to investigate the relationship between BNP plasma concentrations and CVS after aneurysmal SAH. METHODS:BNP plasma concentrations were assessed at 4 different time periods (1 to 3 days, 4 to 6 days, 7 to 9 days, and 10 to 12 days) in 19 patients with spontaneous SAH. BNP plasma levels were investigated with respect to neurological condition, SAH severity on CT, and flow velocities measured by means of transcranial Doppler. RESULTS:Thirteen patients had Doppler evidence of CVS; 7 of these had nonsymptomatic CVS. In 6 patients, CVS was severe and symptomatic, with delayed ischemic lesion on CT in 5 of these. CVS was severe and symptomatic in 6 patients, and delayed ischemic lesions were revealed on CT in 5 of these. BNP levels were found to be significantly elevated in SAH patients compared with control subjects (P=0.024). However, in patients without CVS or with nonsymptomatic CVS, BNP concentrations decreased throughout the 4 time periods, whereas a 6-fold increase was observed in patients with severe symptomatic CVS between the first and the third periods (P=0.0096). A similar trend in BNP plasma levels was found in patients with severe SAH compared with those with nonvisible or moderate SAH (P=0.015). CONCLUSIONS:In conclusion, our results show that BNP plasma levels are elevated shortly after SAH, although they increase markedly during the first week in patients with symptomatic CVS. The present findings suggest that secretion of BNP secretion after spontaneous SAH may exacerbate blood flow reduction due to arterial vasospasm.
Selective Carotid Shunting Based on Intraoperative Transcranial Doppler Imaging during Carotid Endarterectomy: A Retrospective Single-Center Review.
Cho Jun Woo,Jeon Yun-Ho,Bae Chi Hoon
The Korean journal of thoracic and cardiovascular surgery
BACKGROUND:Carotid endarterectomy (CEA) with selective shunting is the surgical method currently used to treat patients with carotid artery disease. We evaluated the incidence of major postoperative complications in patients who underwent CEA with selective shunting under transcranial Doppler (TCD) at our institution. METHODS:The records of 45 patients who underwent CEA with TCD-based selective shunting under general anesthesia from November 2009 to June 2015 were reviewed. The risk factors for postoperative complications were analyzed using univariate and multivariate analysis. RESULTS:Preoperative atrial fibrillation was observed in three patients. Plaque ulceration was detected in 10 patients (22.2%) by preoperative computed tomography imaging. High-level stenosis was observed in 16 patients (35.5%), and 18 patients had contralateral stenosis. Twenty patients (44.4%) required shunt placement due to reduced TCD flow or a poor temporal window. The 30-day mortality rate was 2.2%. No cases of major stroke were observed in the 30 days after surgery, but four cases of minor stroke were noted. Univariate analysis showed that preoperative atrial fibrillation (odds ratio [OR], 40; p=0.018) and ex-smoker status (OR, 17.5; p=0.021) were statistically significant risk factors for a minor stroke in the 30-day postoperative period. Analogously, multivariate analysis also found that atrial fibrillation (p<0.001) and ex-smoker status (p=0.002) were significant risk factors for a minor stroke in the 30-day postoperative period. No variables were identified as risk factors for 30-day major stroke or death. No wound complications were found, although one (2.2%) of the patients suffered from a hypoglossal nerve injury. CONCLUSION:TCD-based CEA is a safe and reliable method to treat patients with carotid artery disease. Preoperative atrial fibrillation and ex-smoker status were found to increase the postoperative risk of a small embolism leading to a minor neurologic deficit.
Transcranial Doppler ultrasonography: From methodology to major clinical applications.
D'Andrea Antonello,Conte Marianna,Cavallaro Massimo,Scarafile Raffaella,Riegler Lucia,Cocchia Rosangela,Pezzullo Enrica,Carbone Andreina,Natale Francesco,Santoro Giuseppe,Caso Pio,Russo Maria Giovanna,Bossone Eduardo,Calabrò Raffaele
World journal of cardiology
Non-invasive Doppler ultrasonographic study of cerebral arteries [transcranial Doppler (TCD)] has been extensively applied on both outpatient and inpatient settings. It is performed placing a low-frequency (≤ 2 MHz) transducer on the scalp of the patient over specific acoustic windows, in order to visualize the intracranial arterial vessels and to evaluate the cerebral blood flow velocity and its alteration in many different conditions. Nowadays the most widespread indication for TCD in outpatient setting is the research of right to left shunting, responsable of so called "paradoxical embolism", most often due to patency of foramen ovale which is responsable of the majority of cryptogenic strokes occuring in patients younger than 55 years old. TCD also allows to classify the grade of severity of such shunts using the so called "microembolic signal grading score". In addition TCD has found many useful applications in neurocritical care practice. It is useful on both adults and children for day-to-day bedside assessment of critical conditions including vasospasm in subarachnoidal haemorrhage (caused by aneurysm rupture or traumatic injury), traumatic brain injury, brain stem death. It is used also to evaluate cerebral hemodynamic changes after stroke. It also allows to investigate cerebral pressure autoregulation and for the clinical evaluation of cerebral autoregulatory reserve.
Prediction of cerebral hyperperfusion after carotid endarterectomy with transcranial Doppler.
Pennekamp C W A,Tromp S C,Ackerstaff R G A,Bots M L,Immink R V,Spiering W,de Vries J P P M,Kappelle L J,Moll F L,Buhre W F,de Borst G J
European journal of vascular and endovascular surgery : the official journal of the European Society for Vascular Surgery
OBJECTIVES:To determine the diagnostic value for predicting cerebral hyperperfusion syndrome (CHS) by adding a transcranial Doppler (TCD) measurement in the early postoperative phase after carotid endarterectomy (CEA). DESIGN:Patients who underwent carotid endarterectomy between January 2004 and August 2010 and in whom both intra- and postoperative TCD monitoring were performed were included. METHODS:In 184 CEA patients the mean velocity (V(mean)) preoperatively (V1), pre-clamping (V2), post-declamping (V3) and postoperatively (V4) was measured using TCD. The intra-operative V(mean) increase ((V3 - V2)/V2) was compared to the postoperative increase ((V4 - V1)/V1) in relation to CHS. CHS was diagnosed if the patient developed neurological complaints in the presence of a preoperative V(mean) increase >100%. RESULTS:Sixteen patients (9%) had an intra-operative V(mean) increase >100% and 22 patients (12%) a postoperative V(mean) increase of >100%. In 10 patients (5%) CHS was diagnosed; two of those had an intra-operative V(mean) increase of >100% and nine postoperative V(mean) increase >100%. This results in a positive predictive value of 13% for the intra-operative and 41% for the postoperative measurement. CONCLUSIONS:Besides the commonly used intra-operative TCD monitoring additional TCD measurement in the early postoperative phase is useful to more accurately predict CHS after CEA.
Transcranial Doppler Ultrasound Detection of Microemboli as a Predictor of Cerebral Events in Patients with Symptomatic and Asymptomatic Carotid Disease: A Systematic Review and Meta-Analysis.
Best L M J,Webb A C,Gurusamy K S,Cheng S F,Richards T
European journal of vascular and endovascular surgery : the official journal of the European Society for Vascular Surgery
OBJECTIVE:Identification of patients who will benefit from carotid endarterectomy is not entirely effective, primarily utilising degree of carotid stenosis. This study aimed at determining if microembolic signals (MES) detected by transcranial Doppler ultrasound (TCD) can provide clinically useful information regarding stroke risk in patients with carotid atherosclerosis. METHODS:A meta-analysis of prospective studies was performed. Three analyses were proposed investigating MES detection as a predictor of: stroke or TIA, stroke alone, and stroke or TIA but with an increased positivity threshold. Subgroup analysis was used to compare pre-operative (symptomatic or asymptomatic) patients and peri- or post-operative patients. RESULTS:Twenty-eight studies reported data regarding both MES status and neurological outcome. Of these, 22 papers reported data on stroke and TIA as an outcome, 19 on stroke alone, and eight on stroke and TIA with increased positivity threshold. At the median pre-test probability of 3.0%, the post-test probabilities of a stroke after a positive and negative TCD were 7.1% (95% CI 5-10.1) and 1.2% (95% CI 0.6-2.5), respectively. In addition, the sensitivities and specificities of each outcome showed that increasing the threshold for positivity to 10 MES per hour would make TCD a more clinically useful tool in peri- and post-operative patients. CONCLUSION:TCD provides clinically useful information about stroke risk for patients with carotid disease and is technically feasible in most patients. However, the generally weak level of evidence constituting this review means definitive recommendations cannot be made.
Effect of hyperglycemia on cerebral blood flow in patients with diabetes.
Nowaczewska Magdalena,Kamińska Anna,Kukulska-Pawluczuk Beata,Junik Roman,Pawlak-Osińska Katarzyna
Diabetes research and clinical practice
AIMS:Diabetes interferes with cerebral blood flow (CBF) and it seems that the effect of acute hyperglycemia on CBF is different from the changes in CBF caused by chronic diabetes. The aim of the study was to check whether there are changes in CBF measured using transcranial Doppler (TCD) in patients with hyperglycemia before and after normalization of glycemia. METHODS:The study involved 29 patients with diabetes and 27 healthy subjects (control group). The TCD test evaluated mean flow velocity (Vm), systolic velocity (Vs) and Gosling's pulsatility index (PI) in both middle cerebral arteries (MCAs). It was performed twice in patients with diabetes (during hyperglycemia and after normalization of glycemia) and once in the control group. RESULTS:The baseline blood flow parameters were similar in both groups. After the normalization of glycemia in patients with diabetes, they showed lower values of Vm and Vs compared to the control group (p < 0.001). Also, the normalization of glycemia caused a decrease in Vm and Vs (p < 0.001) in patients with diabetes. There were no significant differences in PI. CONCLUSIONS:In the patients with hyperglycemia, Vm and Vs in the MCA were higher than during normoglycemia, which was probably related to vasoconstriction and hypervolemia.
Analysis of Hemodynamic Changes in Early Stage after Carotid Stenting by Transcranial Doppler-A Preliminary Study.
Yan Ziguang,Yang Min,Niu Guochen,Zou Yinghua
Annals of vascular surgery
BACKGROUND:Cerebral hyperperfusion syndrome or hemodynamic instability, caused by the hemodynamic changes, often occur within 6 hr after carotid artery stenting (CAS) The postprocedure cerebral hemodynamic change in the early phase, <6 hr after CAS, is largely unknown. In this study, we evaluated the cerebral hemodynamic changes in patients after CAS using transcranial Doppler (TCD). METHODS:From January 2013 to July 2014, medical records of 61 patients who underwent CAS were reviewed retrospectively. Among them, 44 patients had TCD examination before CAS, 1-2 and 3-4 hr after CAS. In the TCD examination, middle cerebral artery (MCA) peak systolic velocity (PSV) and pulsatility index (PI) on the ipsilateral and contralateral sides were measured. Blood pressure, MCA PSV, and PI data were collected and analyzed from the 44 patients who had valid TCD examinations. RESULTS:Blood pressure was 148.4 ± 14.5 mm Hg before CAS: 124.5 ± 13.8 mm Hg 1-2 hr after CAS, and 121.6 ± 12.6 mm Hg 3-4 hr after CAS. On the ipsilateral side, the MCA PSV increased from 85.7 ± 22.8 cm/s before CAS to 101.1 ± 27.1 cm/s (19.9%, P < 0.001) 1-2 hr after CAS, and 99.7 ± 27.0 cm/s (18.2%, P < 0.001) 3-4 hr after CAS. There was no significant difference in MCA PSV between 1-2 and 3-4 hr after CAS (P = 0.200). The PI increased from 0.871 ± 0.167 before CAS to 0.941 ± 0.205 (P = 0.022) 1-2 hr after CAS, and 0.954 ± 0.218 (P = 0.010) 3-4 hr after CAS. On the contralateral side, there was no statistically significant PSV increase in the MCA following CAS. CONCLUSIONS:CAS may induce a significant increase in PSV and PI in the ipsilateral MCA within 4 hr. The MCA PSV increased significantly higher than that on the contralateral side. The PSV had no significant change between 1-2 and 3-4 hr after CAS.
Role of transcranial Doppler ultrasonography in cerebrovascular disease.
Yeo Leonard L L,Sharma Vijay K
Recent patents on CNS drug discovery
Transcranial Doppler ultrasonography (TCD) is the only non-invasive examination that provides a reliable evaluation of intracranial blood flow patterns in real-time, adding physiological information to the anatomical information obtained from other neuroimaging modalities. TCD is relatively cheap, can be performed bedside, and allows monitoring both in acute emergency settings as well as for prolonged periods with a high temporal resolution making it ideal for studying dynamic cerebrovascular responses. Extended applications of transcranial Doppler in enhancing intravenous thrombolysis in acute stroke, emboli monitoring, right-to-left shunt detection and vasomotor reactivity provide important information about the pathophysiology of cerebrovascular ischemia. In acute cerebral ischemia, TCD is capable of providing rapid information about the hemodynamic status of the cerebral circulation, monitoring recanalization in real-time with a potential for enhancing tissue plasminogen activator (TPA) induced thrombolysis. Advanced applications of TCD make it an important and valuable tool for evaluating stroke mechanisms, plan and monitor treatment and determine prognosis. TCD has an established clinical value in the diagnostic workup of stroke patients and is suggested as essential components of a comprehensive stroke center. We have reviewed various recent patents in addition to the diagnostic, therapeutic, as well as, prognostic applications of TCD in patients with cerebrovascular disease.
[New method to predict cerebral hyperperfusion syndrome after carotid endarterectomy by transcranial Doppler].
Liu Bao,Lai Zhi-Chao,Ni Leng,Li Yong-Jun,Zheng Yue-Hong,Wu Wei-Wei,Ye Wei,Zeng Rong,Chen Yu,Shao Jiang,Liu Chang-Wei
Zhonghua wai ke za zhi [Chinese journal of surgery]
OBJECTIVE:To determine the diagnostic value for predicting cerebral hyperperfusion syndrome (CHS) by adding a transcranial Doppler (TCD) measurement at the end of the carotid endarterectomy (CEA) at the operating room. METHODS:Patients who underwent CEA between August 2009 and December 2011 of the prospective clinical trial in whom both intra- and post-operative TCD monitoring were performed were included. The middle cerebral artery velocities pre-clamping, post-declamping and post-operatively were measured by TCD. The intra-operative velocity increase ratio (VR1) was compared to the postoperative velocity increase ratio(VR2) in relation to CHS by calculating the sensitivity,specificity, positive predictive value, negative predictive value. The receiver operating characteristic curve (ROC) were also performed. The area under the curve (AUC) of ROC of VR1 and VR2 were compared.All the data were analyzed using SPSS 20.0 software. RESULTS:VR1 > 100% was identified in 6 patients, while VR2 > 100% was identified in 18 patients, respectively. Ten patients were diagnosed with CHS. The AUC of VR2 (0.728) was higher than AUC of VR1 (0.636). The best fit cutoff point of VR2 was 100%. The sensitivity, specificity, positive predictive value, negative predictive value were 70%, 83%, 39%, 95%, respectively, which demonstrates a better predictive power than VR1. CONCLUSION:Besides the commonly used intra-operative TCD monitoring, additional TCD measurement at the end of the carotid endarterectomy at the operating room is more useful to more accurately predict CHS.
Transcranial Doppler: a stethoscope for the brain-neurocritical care use.
Robba Chiara,Cardim Danilo,Sekhon Mypinder,Budohoski Karol,Czosnyka Marek
Journal of neuroscience research
Transcranial Doppler (TCD) ultrasonography is a noninvasive bedside monitoring technique that can evaluate cerebral blood flow hemodynamics in the intracranial arterial vasculature. TCD allows assessment of linear cerebral blood flow velocity, with a high temporal resolution and is inexpensive, reproducible, and portable. The aim of this review is to provide an overview of the most commonly used TCD derived signals and measurements used commonly in neurocritical care. We describe both basic (flow velocity, pulsatility index) and advanced concepts, including critical closing pressure, wall tension, autoregulation, noninvasive intracranial pressure, brain compliance, and cerebrovascular time constant; we also describe the clinical applications of TCD to highlight their utility in the diagnosis and monitoring of cerebrovascular diseases as the "stethoscope for the brain."
Relative changes in transcranial Doppler velocities are inferior to absolute thresholds in prediction of symptomatic vasospasm after subarachnoid hemorrhage.
Malhotra Konark,Conners James J,Lee Vivien H,Prabhakaran Shyam
Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association
The absolute transcranial Doppler (TCD) velocity threshold has been validated as a screening tool for vasospasm after subarchnoid hemorrhage (SAH). We assessed whether relative changes in velocity were superior to absolute TCD thresholds in the detection of symptomatic vasospasm. We reviewed consecutive patients with aneurysmal SAH who underwent serial TCD monitoring and survived at least 7 days. We recorded initial flow velocity (IFV) and maximal flow velocity (MFV) of the middle cerebral artery (MCA) serially up to 14 days from admission. We calculated relative flow velocity changes (MFV/IFV) and maximum change in mean flow velocity (FVmean) over any consecutive 2 days in addition to standard absolute measures of Lindegaard ratio (LR) and FVmean. We calculated receiver operating characteristic curve and area under curve (AUC) values, sensitivity, specificity, and positive predictive and negative predictive values for these parameters, optimal cutpoints, and various combinations. Forty-eight of 211 patients (23%) developed symptomatic MCA vasospasm. AUC values for various TCD parameters were 0.80 for MCA MFV >175 cm/s, 0.71 for LR >6, 0.64 for MFV/IFV >2, and 0.64 for >70% change in MFV over 2 days. The best characteristics were observed for the combination of MFV >175 cm/s and/or maximal LR >6 (AUC 0.81). Our data suggest that absolute thresholds of TCD FVmean provide the most accurate prediction of symptomatic MCA vasospasm after SAH. Other thresholds, including relative change from baseline and day-to-day changes, are inferior to established absolute thresholds.
Does the sex of acute stroke patients influence the effectiveness of rt-PA?
Al-hussain Fawaz,Hussain Muhammad S,Molina Carlos,Uchino Ken,Shuaib Ashfaq,Demchuk Andrew M,Alexandrov Andrei V,Saqqur Maher,
BACKGROUND:Women have been reported to show more frequent recanalization and better recovery after intravenous (IV) recombinant tissue plasminogen activator (rt-PA) treatment for acute stroke compared with men. To investigate this we studied a series of stroke patients receiving IV rt-PA and undergoing acute transcranial doppler (TCD) examination. METHODS:Acute stroke patients received IV rt-PA and had acute TCD examination within 4 hours of symptom onset at 4 major stroke centers. TCD findings were interpreted using the Thrombolysis in Brain Ischemia (TIBI) flow grading system. The recanalization rates, and poor 3-month outcomes (modified Rankin scale >2) of men and women were compared using the chi-square test. Multiple regression analysis was used to assess sex as a predictor of recanalization and poor 3-month outcome after controlling for age, baseline NIH Stroke Scale (NIHSS), time to treatment, hypertension, and blood glucose. RESULTS:369 patients had TCD examinations before or during IV rt-PA treatment. The 199 (53.9%) men and 170 (46.1%) women had mean ages of 67 ± 13 and 70 ± 14 years, respectively. The sexes did not differ significantly in baseline stroke severity, time to TCD examination, or time to thrombolysis. Of the men, 68 (34.2%) had complete recanalization, 58 (29.1%) had partial recanalization, and 73 (36.6%) had no recanalization. Of the women, 53 (31.2%) had complete recanalization, 46 (27%) had partial recanalization, and 71 (41.8%) had no recanalization (p = 0.6). Multiple regression analyses showed no difference between the sexes in recanalization rate, time to recanalization, or clinical outcome at 3 months. CONCLUSIONS:In our study; sex is not a significant predictor of recanalization rate, time to recanalization or 3-month outcome in stroke patients following IV rt-PA. TRIAL REGISTRATION:Data from CLOTBUST trial Clinicaltrials.gov Identifier: NCT01240356.
Applications of transcranial Doppler in the ICU: a review.
White Hayden,Venkatesh Balasubramanian
Intensive care medicine
OBJECTIVE:Transcranial Doppler (TCD) ultrasonography is a technique that uses a hand-held Doppler transducer (placed on the surface of the cranial skin) to measure the velocity and pulsatility of blood flow within the intracranial and the extracranial arteries. This review critically evaluates the evidence for the use of TCD in the critical care population. DISCUSSION:TCD has been frequently employed for the clinical evaluation of cerebral vasospasm following subarachnoid haemorrhage (SAH). To a lesser degree, TCD has also been used to evaluate cerebral autoregulatory capacity, monitor cerebral circulation during cardiopulmonary bypass and carotid endarterectomies and to diagnose brain death. Technological advances such as M mode, colour Doppler and three-dimensional power Doppler ultrasonography have extended the scope of TCD to include other non-critical care applications including assessment of cerebral emboli, functional TCD and the management of sickle cell disease. CONCLUSIONS:Despite publications suggesting concordance between TCD velocity measurements and cerebral blood flow there are few randomized controlled studies demonstrating an improved outcome with the use of TCD monitoring in neurocritical care. Newer developments in this technology include venous Doppler, functional Doppler and use of ultrasound contrast agents.
Asymptomatic Carotid Stenosis Is Associated With Circadian and Other Variability in Embolus Detection.
Abbott Anne L,Merican Julia,Pearce Dora C,Juric Ana,Worsnop Christopher,Foster Emma,Chambers Brian
Frontiers in neurology
Variability in transcranial Doppler (TCD) detection of embolic signals (ES) is important for risk stratification. We tested the effect of time of day on ES associated with 60-99% asymptomatic carotid stenosis. Subjects were from the Asymptomatic Carotid Stenosis Embolus Detection (ASED) Study such that half were previously ES-positive and half ES-negative with 6-monthly 60-min TCD monitoring. All underwent bilateral TCD monitoring for two 12-h sessions separated by 24 h. ES detection rates were calculated using 6 and 4-h intervals from midnight and effective TCD monitoring time. Ten subjects (8 male, mean age 79.5 years) were monitored. Over 24 h, 5/10 study arteries with 60-99% asymptomatic carotid stenosis were ES-positive (range 1-28 ES/artery, 56 total ES from 177.9 total effective monitoring hours). The remaining five study arteries and all eight successfully monitored contralateral arteries were ES-negative. Using 6-h intervals the mean ES detection rate peaked at 0600-midday (0.64/h) and was lowest 1800-midnight (0.09/h) with an incidence rate ratio of 7.26 (95% CI 2.52-28.64, ≤ 0.001). Using 4-h intervals the mean ES detection rate peaked at 0800-midday (0.64/h) and was lowest midnight-0400 (0.12/h) with an incidence rate ratio of 5.51 (95% CI 1.78-22.67, = 0.001). Embolism associated with asymptomatic carotid stenosis shows circadian variation with highest rates 4-6 h before midday. This corresponds with peak circadian incidence of stroke and other vascular complications. These and ASED Study results show that monitoring frequency, duration, and time of day are important in ES detection.
Spontaneous preoperative microembolic signals detected with transcranial Doppler are associated with vulnerable carotid plaque characteristics.
Van Lammeren G W,Van De Mortel R H,Visscher M,Pasterkamp G,De Borst G J,Moll F L,Vink A,Tromp S C,De Vries J-P P M
The Journal of cardiovascular surgery
AIM:Carotid plaque composition is associated with ipsilateral cerebrovascular events. Among patients with carotid artery stenosis, presence of microembolic signals (MES) detected with transcranial Doppler (TCD) is associated with increased stroke risk. We aimed to investigate whether MES detected with TCD in the outpatient clinic among patients scheduled for carotid endarterectomy, was associated with underlying carotid plaque composition. METHODS:TCD was used to detect MES among 38 symptomatic patients scheduled for carotid endarterectomy. Measurements were performed for 30 minutes. Carotid plaques harvested during CEA were subjected to histopathological examination. Plaques from patients without spontaneous MES were compared with plaques from patients with ≥1 MES. RESULTS:Median time between TCD and surgery was 4 days. At least 1 MES was detected in 10/38 (26%) patients. Five of ten (50%) patients with spontaneous MES had lipid-rich plaques, compared with 5/28 (17.2%) plaques from patients without MES (P=0.048). Luminal thrombus was observed in 6/10 (60.0%) of plaques from patients with MES compared with 7/28 (25.0%) of plaques from patients without MES (P=0.045). CONCLUSION:Spontaneous MES were detected in 26% of symptomatic patients scheduled for CEA and were associated with unstable carotid plaque characteristics. TCD might be a useful tool to help identify patients with vulnerable plaques.
The Combination of Clinical Features, Transcranial Doppler, and Alberta Stroke Program Early Computed Tomography Score (Computed Tomography Angiography) in Predicting Outcome in Intravenous Recombinant Tissue Plasminogen Activator-Treated Patients.
Saqqur Maher,Ghrooda Esseddeeg,Ahmad Aftab,Khan Khurshid,Hussain Muhammad S,Shuaib Ashfaq
Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association
BACKGROUND:Little data exist on using combined baseline clinical neuroimaging and transcranial Doppler (TCD) information in predicting clinical outcome in stroke patients treated with intravenous (IV) thrombolysis. METHODS:Stroke patients received IV recombinant tissue plasminogen activator (rt-PA) and had diagnostic TCD within 3 hours of symptom onset. The TCD result was interpreted using the thrombolysis in brain ischemia (TIBI) flow grading system. Following multiple regression analysis, a grading system was created with 1 point for each of the following: National Institutes of Health Stroke Scale (NIHSS) score of 16 or higher, TIBI score of 1 or lower, and Alberta Stroke Program Early CT Score (ASPECTS) of 6 or lower. The patients' scores were compared to modified Rankin Scale (mRS) scores at 90 days. RESULTS:A total of 349 patients were included. In unvaried analysis, age of 80 years or older (P = .002), an ASPECTS of 6 or lower (P < .001), an NIHSS score of 16 or higher (P < .001), a TIBI score of 1 or lower (P < .001), and a glucose level ≥ 200 mg/dl (P = .04) were associated with poor outcome (mRS score > 2). In the multiple regression analysis, age of 80 years or older, an ASPECTS of 6 or lower, an NIHSS score of 16 or higher, and hyperglycemia were predictors of poor outcome (P < .05). Based on our scoring system, the patients' odds ratios for poor outcome were 7 (95% confidence interval [CI]: 2-23, P = .003), 8 (95% CI: 3-25, P < .001), and 24 (95% CI: 4-151, P = .001) for scores of 1, 2, and 3, respectively, after adjustment for common stroke risk factors. The mean time to recanalization increased as the score increased (score of 0: 160 ± 45 minutes versus score of 3: 186 ± 38 (P = .70). CONCLUSION:A multimodal grading system is useful in predicting outcome in patients treated with IV rt-PA. Those withhigher scores might be candidates for interventional therapy.
Utility of transcranial Doppler ultrasound for the integrative assessment of cerebrovascular function.
Willie C K,Colino F L,Bailey D M,Tzeng Y C,Binsted G,Jones L W,Haykowsky M J,Bellapart J,Ogoh S,Smith K J,Smirl J D,Day T A,Lucas S J,Eller L K,Ainslie P N
Journal of neuroscience methods
There is considerable utility in the use of transcranial Doppler ultrasound (TCD) to assess cerebrovascular function. The brain is unique in its high energy and oxygen demand but limited capacity for energy storage that necessitates an effective means of regional blood delivery. The relative low cost, ease-of-use, non-invasiveness, and excellent temporal resolution of TCD make it an ideal tool for the examination of cerebrovascular function in both research and clinical settings. TCD is an efficient tool to access blood velocities within the cerebral vessels, cerebral autoregulation, cerebrovascular reactivity to CO(2), and neurovascular coupling, in both physiological states and in pathological conditions such as stroke and head trauma. In this review, we provide: (1) an overview of TCD methodology with respect to other techniques; (2) a methodological synopsis of the cerebrovascular exam using TCD; (3) an overview of the physiological mechanisms involved in regulation of the cerebral blood flow; (4) the utility of TCD for assessment of cerebrovascular pathology; and (5) recommendations for the assessment of four critical and complimentary aspects of cerebrovascular function: intra-cranial blood flow velocity, cerebral autoregulation, cerebral reactivity, and neurovascular coupling. The integration of these regulatory mechanisms from an integrated systems perspective is discussed, and future research directions are explored.
A New Transcranial Doppler Scoring System for Evaluating Middle Cerebral Artery Stenosis.
Hao Qing,Feldmann Edward,Balucani Clotilde,Zubizarreta Nicole,Zhong Xiaobo,Levine Steven R
Journal of neuroimaging : official journal of the American Society of Neuroimaging
BACKGROUND AND PURPOSE:Transcranial Doppler (TCD) criteria for cerebrovascular stenosis are only based on velocity with unsatisfactory positive predictive value (PPV) in previous studies. We refined a published scoring system that integrates several characteristics of TCD data in diagnosing middle cerebral artery (MCA) stenosis. METHODS:Using the TCD-digital subtraction angiography (DSA) database from Stroke Outcomes and Neuroimaging of Intracranial Atherosclerosis (SONIA) trial, velocity, spectrum pattern, diffuse ratio, and asymmetry ratio were assessed. The cutpoints were defined for each parameter and a point value was assigned to each category within that parameter. A summed score was calculated for each MCA. The accuracy was assessed for different cutpoints in predicting ≥50% MCA stenosis measured by DSA. Logistic regression and C-statistics were used for analysis. RESULTS:A total of 114 MCAs were included in vessel-based and 87 patients were included in patient-based analysis. Compared to the velocity-only cutpoints in SONIA, the score results in much improved PPV while negative predictive value (NPV) remains unchanged. The score based on mean velocity (score 0: <140 cm/s, score 3: ≥140 cm/s), spectrum pattern (score 0: no turbulence; score 1: mild turbulence; 2: significant turbulence), and asymmetry ratio (score 0: ratio <1.5, score 1: ratio 1.5-2; score 2: ratio ≥2.1) has the highest NPV while PPV remains favorable (PPV: 72% [95% CI 54-90%]; NPV: 84% [95% CI: 75-93%], area under curve [AUC]: .76 [95% CI: .66-.86]). CONCLUSIONS:The multiparameter scoring system incorporating several characteristics of TCD measures yielded higher PPV while maintaining high NPV compared with the single-parameter velocity criteria in diagnosing MCA ≥50% stenosis.
Transcranial Doppler Emboli Identifies Asymptomatic Carotid Patients at High Stroke Risk: Why This Technique Should be Used More Widely.
Spence J David
With modern intensive medical therapy, the annual risk of ipsilateral stroke in asymptomatic carotid stenosis (ACS) is now ∼0.5%. Therefore, even the relative low risks reported from the Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) trial do not justify routine intervention in most (90%) of the patients with ACS. It is therefore necessary to identify the ∼10% to15% of patients with ACS who have a stroke risk high enough to justify intervention. Transcranial Doppler (TCD) embolus detection has been shown in 2 prospective studies (one with 468 patients and the other with 467 patients) to identify patients at high risk and distinguish them from those who would be better served by medical therapy. There is no valid reason why carotid intervention should be carried out in ACS without first identifying that the patient's risk of stroke is higher than the risk of intervention. The best validated way to do this is by TCD embolus detection, and the cost of TCD equipment and training is approximately the same as the cost of 2 carotid stenting procedures in the United States. This procedure should be used more widely.
Diagnostic criteria and yield of real-time transcranial Doppler monitoring of intra-arterial reperfusion procedures.
Rubiera Marta,Cava Luis,Tsivgoulis Georgios,Patterson Damon E,Zhao Limin,Zhang Yi,Anderson Aaron M,Robinson Alice,Harrigan Mark R,Underwood Edward,Horton Joseph,Alexandrov Andrei V
BACKGROUND AND PURPOSE:Intra-arterial (IA) rescue procedures are increasingly used to treat acute ischemic stroke. We implemented continuous transcranial Doppler (TCD) monitoring during these procedures to detect any potentially harmful flow changes. Here, we report diagnostic criteria and yield of TCD monitoring. METHODS:We studied consecutive acute stroke patients who underwent IA reperfusion procedures. TCD flow signatures during these procedures were analyzed and any abnormal findings were documented. RESULTS:Patients were included only if there was successful insonation through the skull; of 56 eligible patients, 51 were included. IA procedures included IA tissue plasminogen activator, use of the Merci retriever, the Penumbra system, balloon angioplasty, and stenting. On TCD monitoring, contrast injections produced high-intensity signals and increased the mean flow velocity (MFV). Deployment of the Merci device appeared as high-intensity, short-duration signals with a transient MFV decrease of 11.5%. The Penumbra system produced lower-intensity signals with a greater transient decrease in MFV during aspiration. IA tissue plasminogen activator significantly increased MFV by 7.5% over Merci and Penumbra flow velocity changes. Power motion Doppler-TCD detected reocclusion in 13 patients, artery-to-artery embolization in 2 patients, air embolism in 2 patients, and hyperperfusion in 6 patients. Overall, the yield of TCD monitoring was positive in 23 (49%) patients who received IA reperfusion procedures. CONCLUSIONS:Our velocity, intensity, and flow signatures criteria for TCD monitoring of IA reperfusion procedures detect reocclusion, hyperperfusion, or thromboembolism and air embolism in nearly half of all procedures. This hemodynamic information can be particularly helpful when neurological assessment is limited or delayed.
Transcranial Doppler ultrasound goal-directed therapy for the early management of severe traumatic brain injury.
Ract Catherine,Le Moigno Sophie,Bruder Nicolas,Vigué Bernard
Intensive care medicine
OBJECTIVE:To evaluate the usefulness of early transcranial Doppler ultrasound (TCD) goal-directed therapy after severe traumatic brain injury initiated before invasive cerebral monitoring is available. DESIGN:Prospective, observational clinical study. SETTING:Surgical intensive care unit, university hospital. PATIENTS AND PARTICIPANTS:Twenty-four severely brain-injured patients. INTERVENTIONS:All patients had TCD measurements immediately on admission (T0) and when invasive cerebral monitoring was available (T1). TCD was considered abnormal when two out of three measured values were outside the following limits: Vm<30 cm/s, Vd<20 cm/s, PI > 1.4. When admission TCD was abnormal, attending physicians modified treatment to increase cerebral perfusion pressure. MEASUREMENTS AND RESULTS:Admission TCD was performed 18+/-11 min (T0) after admission, whereas cerebral invasive monitoring was available 242+/-116 min (T1) after admission. At T0, 11 (46%) patients had abnormal TCD values (group 1) and 13 had normal TCD values (group 2); mean arterial pressure was comparable between groups. All group 1 patients received mannitol and/or norepinephrine. At T1, mean arterial pressure was increased compared to admission in group 1 (105+/-17 mmHg vs. 89+/-15 mmHg, p<0.05) and only two patients had still an abnormal TCD. Although group 1 patients had higher intracranial pressure than those of group 2 (32+/-13 mmHg vs. 22+/-10 mmHg, p<0.01), both cerebral perfusion pressure and jugular venous oxygen saturation were comparable between the groups. CONCLUSIONS:The use of TCD at hospital admission allows identification of severely brain-injured patients with brain hypoperfusion. In such high-risk patients, early TCD goal-directed therapy can restore normal cerebral perfusion and might then potentially help in reducing the extent of secondary brain injury.
Two different days of transcranial Doppler examinations should be performed for detection of right-to-left shunt in acute stroke patients.
Aoki Junya,Kimura Kazumi,Iguchi Yasuyuki,Sakai Kenichiro,Sakamoto Yuki,Terasawa Yuka,Shibazaki Kensaku,Kobayashi Kazuto
Journal of neuroimaging : official journal of the American Society of Neuroimaging
BACKGROUND:We investigated how many contrast-transcranial Doppler (c-TCD) examinations should be performed on different days in patients with acute stroke. METHODS:Consecutive acute stroke patients within 24 hours of onset were enrolled. Presence of RLS was examined using c-TCD examinations on days 1, 7, and 14. Each c-TCD examination used one test without Valsalva maneuver (VM) and three tests with VM. Patients were diagnosed with RLS when TCD detected ≥1 microembolic signal on ≥1 c-TCD examination on any of the days 1, 7, or 14. RESULTS:One hundred seventy patients (105 men [62%]; median age, 74 [IQR, 66-81] years) were enrolled. RLS was diagnosed in 45 patients (26%). RLS was identified on day 1 in 30 patients (18%), on day 7 in 28 patients (16%), and on day 14 in 23 patients (14%; P = .143). Detection rate of RLS by combining day 1 and 7 examinations was significantly higher than that of day 1 alone (25% vs. 18%, P < .001). However, the rate did not increase when results of day 14 were added (25% vs. 26%, P = .250). CONCLUSIONS:c-TCD examinations should be performed on at least two different days to assess the prevalence of RLS.
Cerebral autoregulation in stroke: a review of transcranial Doppler studies.
Aries Marcel J H,Elting Jan W,De Keyser Jacques,Kremer Berry P H,Vroomen Patrick C A J
BACKGROUND AND PURPOSE:Cerebral autoregulation may become impaired after stroke. To provide a review of the nature and extent of any autoregulation impairment after stroke and its course over time, a technique allowing repeated bedside measurements with good temporal resolution is required. Transcranial Doppler (TCD) in combination with continuous blood pressure measurements allows noninvasive continuous bedside investigation with high temporal resolution of the dynamic and the steady-state components of cerebral autoregulation. Therefore, this review focuses on all TCD studies on cerebral autoregulation in the setting of documented ischemic stroke. METHODS:PubMed and EMBASE were searched for studies of stroke, autoregulation, and TCD. Studies were either acute phase (<96 hours after index stroke) or chronic phase (>96 hours after index stroke) autoregulation studies. Quality of studies was studied in a standardized fashion. RESULTS:Twenty-three studies met the inclusion criteria. General agreement existed on cerebral autoregulation being impaired, even after minor stroke. Bilateral impairment of autoregulation was documented, particularly after lacunar stroke. Studies showed progressive deterioration of cerebral autoregulation in the first 5 days after stroke and recovery over the next 3 months. Impaired cerebral autoregulation as assessed by TCD was related to neurological deterioration, the necessity for decompressive surgery, and poor outcome. Synthesis of the data of various studies was, however, limited by studies not meeting key methodological criteria for observational studies. CONCLUSIONS:TCD in combination with continuous blood pressure measurement offers a method with a high temporal resolution feasible for bedside evaluation of cerebral autoregulation in the stroke unit. TCD studies have shown impairment of cerebral autoregulation in various subtypes of ischemic stroke. To improve the synthesis of data from various research groups, there is urgent need for standardization of methodology of TCD studies in cerebral autoregulation.
Monitoring cerebral vasospasm: How much can we rely on transcranial Doppler.
Samagh Navneh,Bhagat Hemant,Jangra Kiran
Journal of anaesthesiology, clinical pharmacology
Cerebral vasospasm leading to delayed cerebral ischaemia is one of the major concerns following subarachnoid haemorrhage (SAH). Various modalities are present for evaluation and detection of cerebral vasospasm that occurs following SAH. They include transcranial Doppler (TCD), computed tomographic angiography (CTA), computed tomographic (CT) perfusion and digital subtraction angiography (DSA). The recent guidelines have advocated the use of TCD and have described it as a reasonable technique for monitoring the development of vasospasm. This review describes the functioning of TCD, the cerebral haemodynamic changes during vasospasm and TCD-based detection of vasospasm. The review shall highlight as to how the TCD derived values are relevant in the settings of neurocritical care. The data in the review have been consolidated based on our search of literature from year 1981 till 2016 using various data base.
Transcranial Doppler Ultrasonography for the Management of Severe Traumatic Brain Injury After Decompressive Craniectomy.
Chang Tao,Li Lihong,Yang Yanlong,Li Min,Qu Yan,Gao Li
BACKGROUND:Cerebral hemodynamic transformation is a relatively common finding in patients with traumatic brain injury (TBI). Knowledge of cerebral hemodynamic disturbance may assist in predicting the management outcome. Transcranial Doppler ultrasonography (TCD) monitoring of patients with TBI can be used to reveal various pathologic hemodynamic changes. The objective of this study was to compare the clinical outcomes of postoperative routine intracranial pressure (ICP) monitoring versus ICP monitoring combined with TCD monitoring in patients with brain trauma after decompressive craniectomy. METHODS:This was a retrospective study of 30 patients with TBI who underwent ICP combined with TCD monitoring (after 2015) compared with a historical control group of 30 patients who only underwent routine ICP monitoring (in 2013-2014). ICP, partial pressure of carbon dioxide, hemoglobin, and hematocrit values were monitored and recorded on a daily basis for 7 days after operation. Neuroimaging was also performed at admission. Neurologic outcome was assessed at 2 weeks and 6 months after operation using the Glasgow Outcome Score Extended (GOS-E). Unconditional multivariable logistic regression was conducted to analyze the factors for favorable clinical outcome. RESULTS:Two weeks after operation, there were no differences in mortality rate between the 2 groups (P = 0.643). When considering the GOS-E score at 6 months, there were no differences in clinical prognosis between the 2 groups (P = 0.101), but the ICP combined with TCD monitoring group showed a higher frequency of patients with favorable outcome compared with the routine ICP monitoring group (P = 0.043). Unconditional multivariable logistic regression results showed that no factor was independently associated with GOS-E at 6 months. CONCLUSIONS:TCD could be helpful for the serial monitoring of cerebral hemodynamic changes after decompressive craniectomy for TBI, which could be beneficial for neurologic outcome improvement.
Diagnostic value of transcranial ultrasonography for selecting subjects with large vessel occlusion: a systematic review.
Antipova Daria,Eadie Leila,Macaden Ashish Stephen,Wilson Philip
The ultrasound journal
INTRODUCTION:A number of pre-hospital clinical assessment tools have been developed to triage subjects with acute stroke due to large vessel occlusion (LVO) to a specialised endovascular centre, but their false negative rates remain high leading to inappropriate and costly emergency transfers. Transcranial ultrasonography may represent a valuable pre-hospital tool for selecting patients with LVO who could benefit from rapid transfer to a dedicated centre. METHODS:Diagnostic accuracy of transcranial ultrasonography in acute stroke was subjected to systematic review. Medline, Embase, PubMed, Scopus, and The Cochrane Library were searched. Published articles reporting diagnostic accuracy of transcranial ultrasonography in comparison to a reference imaging method were selected. Studies reporting estimates of diagnostic accuracy were included in the meta-analysis. RESULTS:Twenty-seven published articles were selected for the systematic review. Transcranial Doppler findings, such as absent or diminished blood flow signal in a major cerebral artery and asymmetry index ≥ 21% were shown to be suggestive of LVO. It demonstrated sensitivity ranging from 68 to 100% and specificity of 78-99% for detecting acute steno-occlusive lesions. Area under the receiver operating characteristics curve was 0.91. Transcranial ultrasonography can also detect haemorrhagic foci, however, its application is largely restricted by lesion location. CONCLUSIONS:Transcranial ultrasonography might potentially be used for the selection of subjects with acute LVO, to help streamline patient care and allow direct transfer to specialised endovascular centres. It can also assist in detecting haemorrhagic lesions in some cases, however, its applicability here is largely restricted. Additional research should optimize the scanning technique. Further work is required to demonstrate whether this diagnostic approach, possibly combined with clinical assessment, could be used at the pre-hospital stage to justify direct transfer to a regional thrombectomy centre in suitable cases.
Decision Criteria for Large Vessel Occlusion Using Transcranial Doppler Waveform Morphology.
Thorpe Samuel G,Thibeault Corey M,Canac Nicolas,Wilk Seth J,Devlin Thomas,Hamilton Robert B
Frontiers in neurology
The current lack of effective tools for prehospital identification of Large Vessel Occlusion (LVO) represents a significant barrier to efficient triage of stroke patients and detriment to treatment efficacy. The validation of objective Transcranial Doppler (TCD) metrics for LVO detection could provide first responders with requisite tools for informing stroke transfer decisions, dramatically improving patient care. To compare the diagnostic efficacy of two such candidate metrics: Velocity Asymmetry Index (VAI), which quantifies disparity of blood flow velocity across the cerebral hemispheres, and Velocity Curvature Index (VCI), a recently proposed TCD morphological biomarker. Additionally, we investigate a simple decision tree combining both metrics. We retrospectively compare accuracy/sensitivity/specificity (ACC/SEN/SPE) of each method (relative to standard CT-Angiography) in detecting LVO in a population of 66 subjects presenting with stroke symptoms (33 with CTA-confirmed LVO), enrolled consecutively at Erlanger Southeast Regional Stroke Center in Chattanooga, TN. Individual VCI and VAI metrics demonstrated robust performance, with area under receiver operating characteristic curve (ROC-AUC) of 94% and 88%, respectively. Additionally, leave-one-out cross-validation at optimal identified thresholds resulted in 88% ACC (88% SEN) for VCI, vs. 79% ACC (76% SEN) for VAI. When combined, the resultant decision tree achieved 91% ACC (94% SEN). We conclude VCI to be superior to VAI for LVO detection, and provide evidence that simple decision criteria incorporating both metrics may further optimize. Our results suggest that machine-learning approaches to TCD morphological analysis may soon enable robust prehospital LVO identification. Was not required for this feasibility study.
Velocity Curvature Index: a Novel Diagnostic Biomarker for Large Vessel Occlusion.
Thorpe Samuel G,Thibeault Corey M,Wilk Seth J,O'Brien Michael,Canac Nicolas,Ranjbaran Mina,Devlin Christian,Devlin Thomas,Hamilton Robert B
Translational stroke research
Despite being a conveniently portable technology for stroke assessment, Transcranial Doppler ultrasound (TCD) remains widely underutilized due to complex training requirements necessary to reliably obtain and interpret cerebral blood flow velocity (CBFV) waveforms. The validation of objective TCD metrics for large vessel occlusion (LVO) represents a first critical step toward enabling use by less formally trained personnel. In this work, we assess the diagnostic utility, relative to current standard CT angiography (CTA), of a novel TCD-derived biomarker for detecting LVO. Patients admitted to the hospital with stroke symptoms underwent TCD screening and were grouped into LVO and control groups based on the presence of CTA confirmed occlusion. Velocity curvature index (VCI) was computed from CBFV waveforms recorded at multiple depths from the middle cerebral arteries (MCA) of both cerebral hemispheres. VCI was assessed for 66 patients, 33 of which had occlusions of the MCA or internal carotid artery. Our results show that VCI was more informative when measured from the cerebral hemisphere ipsilateral to the site of occlusion relative to contralateral. Moreover, given any pair of bilateral recordings, VCI separated LVO patients from controls with average area under receiver operating characteristic curve of 92%, which improved to greater than 94% when pairs were selected by maximal velocity. We conclude that VCI is an analytically valid candidate biomarker for LVO diagnosis, possessing comparable accuracy, and several important advantages, relative to current TCD diagnostic methodologies.
Better With Ultrasound: Transcranial Doppler.
Lau Vincent I,Jaidka Atul,Wiskar Katie,Packer Nicholas,Tang J Elaine,Koenig Seth,Millington Scott J,Arntfield Robert T
Transcranial Doppler (TCD) ultrasound is a noninvasive method of obtaining bedside neurologic information that can supplement the physical examination. In critical care, this can be of particular value in patients who are unconscious with an equivocal neurologic examination because TCD findings can help the physician in decisions related to more definitive imaging studies and potential clinical interventions. Although TCD is traditionally the domain of sonographers and radiologists, there is increasing adoption of goal-directed TCD at the bedside in the critical care environment. The value of this approach includes round-the-clock availability and a goal-directed approach allowing for repeatability, immediate interpretation, and quick clinical integration. This paper presents a systematic approach to incorporating the highest yield TCD techniques into critical care bedside practice, and includes a series of illustrative figures and narrated video presentations to demonstrate the techniques described.
Hyperperfusion syndrome after carotid endarterectomy and carotid stenting.
Buczek Julia,Karliński Michał,Kobayashi Adam,Białek Paweł,Członkowska Anna
Cerebrovascular diseases (Basel, Switzerland)
BACKGROUND:Hyperperfusion syndrome (HS) is a relatively rare but possibly serious complication of carotid revascularization procedures. Impaired cerebral autoregulation and postrevascularization changes in cerebral blood flow are the main mechanisms involved in the development of HS. Most up-to-date studies addressing this issue are retrospective and tend to concentrate on carotid endarterectomy (CEA), neglecting carotid stenting (CAS). Our aim was to compare the frequency of clinical signs of HS and hyperperfusion detected by transcranial Doppler (TCD) in patients undergoing CAS or CEA due to carotid stenosis. METHODS:In this prospective observational study, we evaluated 61 patients scheduled for routine CAS or CEA. Each patient was examined by a neurologist before and after the revascularization procedure to assess the clinical status. Severe headache, ocular or facial pain, confusion, visual disturbances, epileptic seizures or any focal deficits not caused by cerebral ischemia were considered clinical signs of HS. Peak systolic velocity (PSV), end-diastolic velocity, mean velocity (MV), and pulsatility index were measured by TCD once before and twice after the intervention (within 6 h after and 2-5 days after the procedure). Hyperperfusion was defined as a >100% increase in the middle cerebral artery (MCA) blood velocity, evaluated separately for PSV and MV after the procedure compared with the baseline value. Cerebrovascular reactivity (CVR) was evaluated with a TCD acetazolamide test before the intervention. RESULTS:CAS (n = 33) and CEA (n = 28) patients were included in the study. There was no difference between the groups in the frequency of clinical signs of HS (21.2 vs. 21.4%) and ratio of TCD hyperperfusion (12.1 vs. 14.3%). In the CAS group, ipsilateral MCA velocity significantly increased directly after the intervention and 2-5 days later, while it increased in the CEA group only 2-5 days after the intervention. The sensitivity and specificity of hyperperfusion, defined by MV, for HS signs were 38.5 and 93.8%, respectively, whereas those defined by PSV were 30.8 and 89.6%, respectively. The sensitivity and specificity of impaired CVR (<25%) for HS signs were 63.6 and 73.5%, respectively. CONCLUSIONS:There is no difference in the frequency of HS clinical signs and hyperperfusion detected by TCD between patients after CAE and CAS. Clinical signs suggested HS does not always correspond with TCD hyperperfusion. However, both the CVR test and TCD measurements of MCA velocity can help identify patients at high risk for HS.
Trancranial Doppler: value in clinical practice.
Martinelli O,Benedetti-Valentini F
International angiology : a journal of the International Union of Angiology
The value of TCD in clinical practice is well established since it can be used to measure cerebral vasomotor reactivity and to detect and grade vasospasm (VSP) following subarachnoid haemorrhage and cerebral blood perfusion consequences of extracranial ICA stenosis or occlusion. Intracranial steno-occlusive disease can be detected more reliably by transcranial color-coded imaging (TCCI) that provides a two-dimensional imaging of parenchymal and vascular anatomy of brain too. In patients with suspected brain TCD diagnostic criteria for brain death have a sensitivity of 91 to 100% and specificity of 97 to 100% and they are particularly useful when clinical and EEG evaluations are difficult. TCD is a sensitive technique for real time detection of microembolic signals (MES) from prosthetic cardiac valves, myocardial infarction site, atrial fibrillation, aortic arch atheroma and this suggests the use of TCD for monitoring response to antithrombotic therapy. There is also a high correlation between contrast-enhanced TCD and trans-esophageal echocardiography for detecting paradoxical embolism through right-to-left cardiac or pulmonary shunts. Microembolization detected by TCD monitoring may confirm features of unstable carotid artery plaques as imaged by Duplex scanning and there is an increasing evidence that asymptomatic MES from unstable carotid plaques are an independent factor for ischemic stroke. TCD can be used as a monitoring tool during cardiac surgery and cerebrovascular operations to determine critical hemodynamic changes in cerebral arteries and to identify high-intensity transients referred to air or particulate emboli. Several research studies of the past 10 years have shown that MES may be detected by TCD during all phases of CEA and CAS and that sustained microembolism after carotid flow restoration is an indication of impending postoperative or post-procedural occlusion. Our series showed a clear difference between the number of patients with MES and the incidence rate of MES in each patient submitted to CAS (100% of cases with 35-250 MES in each case) and to CEA (74% of cases with 2-30 MES in each case). We also observed a decrease in the incidence rate of microembolic events by TCD during CAS with or without brain protection devices , 18.% and 40%, respectively. There is a statistically significant difference between the neurological deficit related to embolism during CEA (1.8% of cases) and during CAS(9 %). Furthermore DWI has shown a higher prevalence of postoperative small areas of brain ischemia due to asymptomatic embolism occurring during CAS than after carotid surgery according with a higher incidence of patients suffering from neuropsychological impairment after CAS as compared with those submitted to CEA . The use of TCD can provide new insights into pathophysiology of cerebral steno-occlusive and functional diseases, it can helps in risk stratifications of patients with cardio-embolic sources and in the choice and monitoring of medical, surgical or endovascular treatment. TCD monitoring during carotid revascularization either surgical or endovascular can alert the operator to take appropriate measures to avoid brain ischemia and provides useful data for choice and control of the different brain protection devices.
Paradoxical cerebrovascular hemodynamic changes with nicardipine.
Lahiri Shouri,Nezhad Mani,Schlick Konrad H,Rinsky Brenda,Rosengart Axel,Mayer Stephan A,Lyden Patrick D
Journal of neurosurgery
OBJECTIVE Intravenous nicardipine is commonly used for blood pressure reduction in patients with acute stroke. However, few studies have described its effects on cerebrovascular hemodynamics as measured by transcranial Doppler (TCD) waveform analysis and pulsatility index (PI). In this study, the authors report examples of a consistent but paradoxical finding associated with nicardipine that suggests intracranial vasoconstriction, contrary to what is expected from a vasodilator. METHODS The data presented are from a convenience sample of patients who underwent TCD monitoring before, after, or during nicardipine administration. In each case, TCD waveform morphologies and PIs were compared. RESULTS The TCD waveforms during nicardipine infusion are characterized by a prominent systolic peak and dicrotic notch. Systolic deceleration was more pronounced and PIs were significantly elevated in patients who were on nicardipine (p < 0.001). This finding was not evident when patients were not on nicardipine. CONCLUSIONS This study provides the first evidence of paradoxical intracranial vasoconstriction associated with intravenous nicardipine. In the authors' experience, this finding is consistently encountered in the vast majority of patients who are treated with intravenous nicardipine, and is contradictory to what is expected from a vasodilator. Future studies are needed to confirm this finding in larger populations and diverse clinical settings and to examine mechanisms that explain this phenomenon.
Transcranial Doppler for evaluation of cerebral autoregulation.
Panerai Ronney B
Clinical autonomic research : official journal of the Clinical Autonomic Research Society
Transcranial Doppler ultrasound (TCD) can measure cerebral blood flow velocity in the main intracranial vessels non-invasively and with high accuracy. Combined with the availability of non-invasive devices for continuous measurement of arterial blood pressure, the relatively low cost, ease-of-use, and excellent temporal resolution of TCD have stimulated the development of new techniques to assess cerebral autoregulation in the laboratory or bedside using a dynamic approach, instead of the more classical 'static' method. Clinical applications have shown consistent results in certain conditions such as severe head injury and carotid artery disease. Studies in syncopal patients revealed a more complex pattern due to aetiological non-homogeneity and methodological limitations mainly due to inadequate sample-size. Different analytical models to quantify autoregulatory performance have also contributed to the diversity of results in the literature. The review concludes with specific recommendations for areas where further validation and research are needed to improve the reliability and usefulness of TCD in clinical practice.
Non-Invasive Pressure Reactivity Index Using Doppler Systolic Flow Parameters: A Pilot Analysis.
Zeiler Frederick A,Smielewski Peter,Stevens Andrew,Czosnyka Marek,Menon David K,Ercole Ari
Journal of neurotrauma
The goal was to predict pressure reactivity index (PRx) using non-invasive transcranial Doppler (TCD) based indices of cerebrovascular reactivity, systolic flow index (Sx_a), and mean flow index (Mx_a). Continuous extended duration time series recordings of middle cerebral artery cerebral blood flow velocity (CBFV) were obtained using robotic TCD in parallel with direct intracranial pressure (ICP). PRx, Sx_a, and Mx_a were derived from high frequency archived signals. Using time-series techniques, autoregressive integrative moving average (ARIMA) structure of PRx was determined and embedded in the following linear mixed effects (LME) models of PRx: PRx ∼ Sx_a and PRx ∼ Sx_a + Mx_a. Using 80% of the recorded patient data, the LME models were created and trained. Model superiority was assessed via Akaike information criterion (AIC), Bayesian information criterion (BIC), and log-likelihood (LL). The superior two models were then used to predict PRx using the remaining 20% of the signal data. Predicted and observed PRx were compared via Pearson correlation, linear models, and Bland-Altman (BA) analysis. Ten patients had 3-4 h of continuous uninterrupted ICP and TCD data and were used for this pilot analysis. Optimal ARIMA structure for PRx was determined to be (2,0,2), and this was embedded in all LME models. The top two LME models of PRx were determined to be: PRx ∼ Sx_a and PRx ∼ Sx_a + Mx_a. Estimated and observed PRx values from both models were strongly correlated (r > 0.9; p < 0.0001 for both), with acceptable agreement on BA analysis. Predicted PRx using these two models was also moderately correlated with observed PRx, with acceptable agreement (r = 0.797, p = 0.006; r = 0.763, p = 0.011; respectively). With application of ARIMA and LME modeling, it is possible to predict PRx using non-invasive TCD measures. These are the first and as well as being preliminary attempts at doing so. Much further work is required.
Cerebral blood flow velocity underestimates cerebral blood flow during modest hypercapnia and hypocapnia.
Coverdale Nicole S,Gati Joseph S,Opalevych Oksana,Perrotta Amanda,Shoemaker J Kevin
Journal of applied physiology (Bethesda, Md. : 1985)
To establish the accuracy of transcranial Doppler ultrasound (TCD) measures of middle cerebral artery (MCA) cerebral blood flow velocity (CBFV) as a surrogate of cerebral blood flow (CBF) during hypercapnia (HC) and hypocapnia (HO), we examined whether the cross-sectional area (CSA) of the MCA changed during HC or HO and whether TCD-based estimates of CBFV were equivalent to estimates from phase contrast (PC) magnetic resonance imaging. MCA CSA was measured from 3T magnetic resonance images during baseline, HO (hyperventilation at 30 breaths/min), and HC (6% carbon dioxide). PC and TCD measures of CBFV were measured during these protocols on separate days. CSA and TCD CBFV were used to calculate CBF. During HC, CSA increased from 5.6 ± 0.8 to 6.5 ± 1.0 mm(2) (P < 0.001, n = 13), while end-tidal carbon dioxide partial pressure (PETCO2) increased from 37 ± 3 to 46 ± 5 Torr (P < 0.001). During HO, CSA decreased from 5.8 ± 0.9 to 5.3 ± 0.9 mm(2) (P < 0.001, n = 15), while PetCO2 decreased from 36 ± 4 to 23 ± 3 Torr (P < 0.001). CBFVs during baseline, HO, and HC were compared between PC and TCD, and the intraclass correlation coefficient was 0.83 (P < 0.001). The relative increase from baseline was 18 ± 8% greater (P < 0.001) for CBF than TCD CBFV during HC, and the relative decrease of CBF during HO was 7 ± 4% greater than the change in TCD CBFV (P < 0.001). These findings challenge the assumption that the CSA of the MCA does not change over modest changes in PETCO2.
Usefulness of transcranial Doppler-derived cerebral hemodynamic parameters in the noninvasive assessment of intracranial pressure.
Wakerley Benjamin R,Kusuma Yohanna,Yeo Leonard L L,Liang Shen,Kumar Komal,Sharma Arvind K,Sharma Vijay K
Journal of neuroimaging : official journal of the American Society of Neuroimaging
BACKGROUND:Transcranial Doppler (TCD) ultrasonography is a noninvasive bedside tool that can evaluate cerebral blood flow hemodynamics in major intracranial arteries. TCD-derived pulsatility index (PI) is believed to be influenced by intracranial pressure (ICP). OBJECTIVE:To correlate TCD-PI with cerebrospinal fluid (CSF) pressure (representing ICP), measured by standard lumbar puncture (LP) manometry. METHODS:CSF pressures (CSF-P) were measured in 78 patients by LP manometry. Stable TCD spectra were obtained 5 minutes before LP from either middle cerebral arteries using Spencer's head frame and 2-MHz transducer. PI values were calculated from the TCD spectra by an independent neurosonologist. RESULTS:Factors displaying a significant relationship with CSF-P included age (R = -.426, P < .0005); EDV (R = -.328, P = .002;) and PI (R = .650, P < .0005). On analyzing dichotomized data (CSF-P < 20 vs. ≥ 20 cm H2 0) TCD-PI was an independent determinant (OR per .1 increase in PI = 2.437; 95% CI, 1.573-3.777; P < .0005). PI ≥ 1.26 could reliably predict CSF-P ≥ 20 cm H2 0 (sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy were 81.1%, 96.3%, 93.8%, 88.1%, and 90.1% respectively). CONCLUSION:TCD-derived PI could be used to identify patients with CSF-P ≥ 20 cm H2 0 and may play an important role as a monitoring tool.
Transcranial Doppler ultrasonography in acute ischemic stroke predicts stroke subtype and clinical outcome: a study in Omani population.
Gujjar Arunodaya R,William Ranjan,Jacob P C,Jain Rajeev,Al-Asmi Abdullah R
Journal of clinical monitoring and computing
BACKGROUND:Transcranial Doppler ultrasonography (TCD) is being increasingly used for its ability to provide cerebral hemodynamic information in stroke. Few studies have explored its association with cerebral arteriographic changes and stroke subtype. This study explored the relation of TCD changes in acute stroke with stroke subtypes, MR cerebral arteriography and clinical outcome in Omani population. METHODS:Adult patients presenting with acute ischemic stroke within 4 days of stroke onset were subjected to TCD through the temporal and suboccipital windows using a 2 MHz probe; flow velocities, pulsatility and direction of flow were recorded from arteries at the skull base. MR arteriographic (MRA) changes on corresponding arteries were graded on a scale of 1-4. ANOVA, student's t test and ROC analysis were used to evaluate TCD in relation to stroke type, outcome and stenosis on MRA. RESULTS:Of 60 patients recruited, 52 (M:F::36:16; mean age: 60 + 13 years) had adequate bone window for TCD study. Large artery stroke occurred in 30 (58%) patients; lacunar stroke-11 (21%); cardioembolic and mixed groups 9 (17%), other specificed causes-2 (4%). 86.5% had evidence of intracranial disease. 10/52 patients (19%) died while 33 (63%) had good outcome (modified Rankin Score 0-3). Of the 186 arteries studied by the two methods, 52 had TCD evidence of stenosis while 42 were abnormal on MRA, giving a sensitivity of 60%, specificity: 81.25%; positive likelihood ratio: 3.18 and negative likelihood ratio: 0.5. 29/52 (56%) of patients had TCD changes in the arteries corresponding to stroke location. Abnormal TCD was associated with large artery strokes (p = 0.007), poor outcome (p = 0.038) and mortality (p = 0.01). CONCLUSION:This study of TCD in acute stroke in Omani population demonstrates a relatively higher burden of intracranial arterial disease. TCD changes are associated with type of stroke and outcome in this population. TCD is a simple and fairly useful method of evaluation in patients with acute stroke. Adopting TCD in evaluation of stroke patients may provide useful information regarding the pathophysiology which could enhance patient management.
Pre-hospital transcranial Doppler in severe traumatic brain injury: a pilot study.
Tazarourte K,Atchabahian A,Tourtier J-P,David J-S,Ract C,Savary D,Monchi M,Vigué B
Acta anaesthesiologica Scandinavica
BACKGROUND:Investigation of the feasibility and usefulness of pre-hospital transcranial Doppler (TCD) to guide early goal-directed therapy following severe traumatic brain injury (TBI). METHODS:Prospective, observational study of 18 severe TBI patients during pre-hospital medical care. TCD was performed to estimate cerebral perfusion in the field and upon arrival at the Level 1 trauma centre. Specific therapy (mannitol, noradrenaline) aimed at improving cerebral perfusion was initiated if the initial TCD was abnormal (defined by a pulsatility index >1.4 and low diastolic velocity). RESULTS:Nine patients had a normal initial TCD and nine an abnormal one, without a significant difference between groups in terms of the Glasgow Coma Scale or the mean arterial pressure. Among patients with an abnormal TCD, four presented with an initial areactive bilateral mydriasis. Therapy normalized TCD in five patients, with reversal of the initial mydriasis in two cases. Among these five patients for whom TCD was corrected, only two died within the first 48 h. All four patients for whom the TCD could not be corrected during transport died within 48 h. Only patients with an initial abnormal TCD required emergent neurosurgery (3/9). Mortality at 48 h was significantly higher for patients with an initial abnormal TCD. CONCLUSIONS:Our preliminary study suggests that TCD could be used in pre-hospital care to detect patients whose cerebral perfusion may be impaired.
Transcranial Doppler and Hematoma Expansion in Acute Spontaneous Primary Intracerebral Hemorrhage.
Kesav Praveen,Khurana Dheeraj,Prabhakar Sudesh K,Ahuja Chirag K,Khandelwal Niranjan
Annals of Indian Academy of Neurology
Context:The data on the role of Transcranial Doppler (TCD) in the management of acute primary intracerebral hemorrhage (ICH) is meager. Aims:To study TCD variables associated with hematoma expansion in acute primary ICH. Settings and Design:The study was carried out in the neurosciences department of Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh from July 2010 to September 2011 employing a prospective, double blinded non randomized study design. Materials and Methods:Acute ICH patients within 24 h of symptom onset were recruited. Baseline neuroimaging study (Computerized tomography, CT scan of brain) was performed to assess the pure hematoma volume by AXBXC/2 method. Baseline TCD parameters were obtained from both the middle cerebral arteries (MCAs; affected and unaffected hemisphere): Peak Systolic velocity, End Diastolic velocity, Mean Flow velocity, Resistance Index, and Pulsatility Index. Follow up (24 h) assessment of hematoma volume and TCD were carried out. Each of the TCD variables were compared in hematoma expansion (>33% increase in hematoma volume on the follow-up CT) and non-expansion group. Statistical analysis:On univariate analysis, the Student's -test and contingency tables with the X test were used. A forward stepwise multivariate logistic regression analysis with hematoma expansion at 24 h as the dependent variable and ROC analysis was carried out, using SPSS software version 16 (Chicago, IL). value < 0.05 was considered significant. Results:Twenty-five patients completed the study. Ten patients (40%) had hematoma expansion. Multivariate analysis revealed unaffected hemisphere MCA Pulsatility Index ratio [unaffected hemisphere MCA Follow up Pulsatility Index/baseline Pulsatility Index] of > 1.055 as the lone correlate of hematoma expansion (sensitivity of 90% and specificity of 60%). Conclusion:Frequent assessment with TCD could aid in prediction of hematoma expansion by measuring unaffected hemisphere Pulsatility Index ratios.
Incorporation of Transcranial Doppler into the ED for the neurocritical care patient.
Montrief Tim,Alerhand Stephen,Jewell Corlin,Scott Jeffery
The American journal of emergency medicine
INTRODUCTION:In the catastrophic neurologic emergency, a complete neurological exam is not always possible or feasible given the time-sensitive nature of the underlying disease process, or if emergent airway management is indicated. As the neurologic exam may be limited in some patients, the emergency physician is reliant on the assessment of brainstem structures to determine neurological function. Physicians thus routinely depend on advanced imaging modalities to further investigate for potential catastrophic diagnoses. Acquiring these tests introduces the risks of transport as well as delays in managing time-sensitive neurologic processes. A more immediate, non-invasive bedside approach complementing these modalities has evolved: Transcranial Doppler (TCD). OBJECTIVE:This narrative review will provide a description of scenarios in which TCD may be applicable. It will summarize the sonographic findings and associated underlying pathophysiology in such neurocritical care patients. An illustrated tutorial, along with pearls and pitfalls, is provided. DISCUSSION:Although there are numerous formalized TCD protocols utilizing four views (transtemporal, submandibular, suboccipital, and transorbital), point-of-care TCD is best accomplished through the transtemporal window. The core applications include the evaluation of midline shift, vasospasm after subarachnoid hemorrhage, acute ischemic stroke, and elevated intracranial pressure. An illustrative tutorial is provided. CONCLUSIONS:With the wide dissemination of bedside ultrasound within the emergency department, there is a unique opportunity for the emergency physician to utilize TCD for a variety of conditions. While barriers to training exist, emergency physician performance of limited point-of-care TCD is feasible and may provide rapid and reliable clinical information with high temporal resolution.
The Role of Transcranial Doppler in Cerebral Vasospasm: A Literature Review.
Sharma Sayesha,Lubrica Reggie Jayson,Song Minwoo,Vandse Rashmi,Boling Warren,Pillai Promod
Acta neurochirurgica. Supplement
Transcranial Doppler ultrasonography (TCD) is a noninvasive technique used to detect vasospasms following a subarachnoid hemorrhage. While the gold standard to evaluate vasospasms is angiography, this technique is invasive and poses additional risks as compared to TCD. TCD is performed by insonating circle of Willis arteries to measure cerebral flow velocity. TCD allows dynamic monitoring of CBF-V and vessel pulsatility, with a high temporal resolution. It is relatively inexpensive, repeatable, and portable; however, the performance of TCD is highly operator dependent and can be difficult, especially with inadequate acoustic windows. This review summarizes the use of transcranial Doppler ultrasonography (TCD) for the assessment of cerebral vasospasm.
Transcranial Doppler Systolic Flow Index and ICP-Derived Cerebrovascular Reactivity Indices in Traumatic Brain Injury.
Zeiler Frederick A,Cardim Danilo,Donnelly Joseph,Menon David K,Czosnyka Marek,Smielewski Peter
Journal of neurotrauma
The purpose of our study was to explore relationships between transcranial Doppler (TCD) indices of cerebrovascular reactivity and those derived from intracranial pressure (ICP). Goals included: A) confirming previously described co-variance patterns of TCD/ICP indices, and B) describing thresholds for systolic flow index (Sx; correlation between systolic flow velocity [FVs] and cerebral perfusion pressure [CPP]) associated with outcome. In a retrospective cohort of traumatic brain injury (TBI) patients: with TCD and ICP monitoring, we calculated various continuous indices of cerebrovascular reactivity: A) ICP (pressure reactivity index [PRx]: correlation between ICP and mean arterial pressure [MAP]; PAx: correlation between pulse amplitude of ICP [AMP] and MAP; RAC: correlation between AMP and CPP) and B) TCD (mean flow index [Mx]: correlation between mean flow velocity [FVm] and CPP; Mx_a: correlation between FVm and MAP; Sx: correlation between FVs and CPP; Sx_a: correlation between FVs and MAP; Dx: correlation between diastolic flow velocity [FVd] and CPP; Dx_a: correlation between FVd and MAP). We assessed the relationships via various statistical techniques, including: principal component analysis, agglomerative hierarchal clustering, and k-means cluster analysis (KMCA). We performed sequential χ testing to define thresholds associated with outcome for Sx/Sx_a. Outcome was assessed at 6 months via dichotomized Glasgow Outcome Score (GOS): A) Favorable (GOS 4 or 5) versus Unfavorable (GOS 3 or less), B) Alive versus Dead. We analyzed 410 recordings in 347 patients. All analyses confirmed our previously described co-variance of Sx/Sx_a with ICP-derived indices. Sx displayed thresholds of -0.15 for unfavorable outcome (p < 0.0001) and -0.20 for mortality (p < 0.0001). Sx_a displayed thresholds of +0.05 (p = 0.019) and -0.10 (p = 0.0001) for alive/dead and favorable/unfavorable outcomes. TCD systolic indices are most closely associated with ICP indices. Sx and Sx_a likely provide better approximation of ICP indices, compared with Mx/Mx_a/Dx/Dx_a. Sx provides superior outcome prediction, versus Mx, with defined thresholds.
Prospective validation study of transorbital Doppler ultrasound imaging for the detection of transient cerebral microemboli.
Saedon M,Dilshad A,Tiivas C,Virdee D,Hutchinson C E,Singer D R J,Imray C H E
The British journal of surgery
BACKGROUND:Transient cerebral microemboli are independent biomarkers of early risk of ischaemic stroke in acute carotid syndromes. Transcranial Doppler imaging (TCD) through the temporal bone is the standard method for detection of cerebral microemboli, but an acoustic temporal bone window for TCD is not available in around one in seven patients. Transorbital Doppler imaging (TOD) has been used when TCD is not possible. The aim of this study was to validate the use of TOD against TCD for detecting cerebral microemboli. METHODS:The study included patients undergoing elective carotid endarterectomy; all had confirmed temporal and orbital acoustic windows. Subjects gave written informed consent to postoperative TCD and TOD monitoring, which was performed simultaneously for 30 min by two vascular scientists. RESULTS:The study included 100 patients (mean(s.e.m.) age 72(1) years; 65 men). Microemboli were detected by one or both methods in 40·0 per cent of patients: by TOD and TCD in 24 patients, by TOD alone in ten and by TCD alone in six. For detecting microemboli, TOD had a sensitivity of 80·0 per cent, specificity of 86·1 per cent, positive predictive value of 71·6 per cent and negative predictive value of 91·2 per cent. Bland-Altman analysis revealed no significant bias (bias 0·11 (95 per cent c.i. -0·52 to 0·74) microemboli; P = 0·810) with upper and lower limits of agreement of +6 and -6 microemboli. CONCLUSION:TOD appears a valid alternative to TCD for detecting microembolic signals in patients with no suitable temporal acoustic window.
The value of transcranial Doppler derived pulsatility index for diagnosing cerebral small-vessel disease.
Ghorbani Abbas,Ahmadi Mohammad Javad,Shemshaki Hamidreza
Advanced biomedical research
BACKGROUND:The pulsatility index (PI), measured by transcranial Doppler (TCD) ultrasonography, can reflect vascular resistance induced by cerebral small-vessel disease (SVD). We evaluated the value of TCD-derived PI for diagnosing SVD as compared with magnetic resonance imaging (MRI). MATERIALS AND METHODS:Fifty-six consecutive cases with SVD (based on MRI) and 48 controls with normal MRI underwent TCD. Based on MRI findings, patients were categorized into five subgroups of preventricular hyperintensity (PVH), deep white matter hyperintensity (DWMH), lacunar, pontin hyperintensity (PH), and PVH+DWMH+lacunar. The sensitivity and specificity of TCD in best PI cut-off points were calculated in each group. RESULTS:The sensitivity and specificity of TCD in comparison with MRI with best PI cut-off points were as follows: In PVH with PI = 0.83, the sensitivity and specificity was 90% and 98%, respectively. In DWMH with PI = 0.79, the sensitivity and specificity was 75% and 87.5%, respectively. In lacunar with PI = 0.80, the sensitivity and specificity was 73% and 90%, respectively. In PH with PI = 0.69, the sensitivity and specificity was 92% and 87.5%, respectively. And, in PVH+DWMH+lacunar subgroup with PI = 0.83, the sensitivity and specificity was 90% and 96%, respectively. CONCLUSIONS:Increased TCD derived PI can accurately indicate the SVD. Hence, TCD can be used as a non-invasive and inexpensive method for diagnosing SVD, and TCD-derived PI can be considered as a physiologic index of the disease as well.
Automatic detection of emboli in the TCD RF signal using principal component analysis.
Cowe Joanne,Evans David H
Ultrasound in medicine & biology
The transcranial Doppler (TCD) radio-frequency (RF) signal can provide additional information on events recorded during ultrasonic monitoring. Embolic signals appear as uniform and predictable shapes within the RF signal, enabling pattern recognition and image processing techniques to be used for their automated detection. This paper uses principal component analysis (PCA) to characterise the typical variation in embolic signal shape, within the RF signal, using training sets of in vitro and in vivo data. PCA techniques are then utilised to discriminate between previously unseen embolic and artifact signals. Although the results of this study show that the algorithms described in this paper do not yet have the accuracy required for their use in a clinical setting, it does demonstrate that this novel technique has the potential to be developed further.
Identification of patients at risk for ischaemic cerebral complications after carotid endarterectomy with TCD monitoring.
Horn J,Naylor A R,Laman D M,Chambers B R,Stork J L,Schroeder T V,Nielsen M-Y,Dunne V G,Ackerstaff R G A
European journal of vascular and endovascular surgery : the official journal of the European Society for Vascular Surgery
OBJECTIVES:Transcranial Doppler (TCD) monitoring for micro embolic signals (MES), directly after carotid endarterectomy (CEA) may identify patients at risk of developing ischaemic complications. In this retrospective multicentre study, this hypothesis was investigated. METHODS:Centres that monitored for MES after CEA were identified by searching Medline. Individual patient data were obtained from centres willing to collaborate. The number of emboli in 1h was computed. Uni- and multivariate logistic regression analyses were performed for the variables gender, age and number of MES. Discriminative ability of MES monitoring was investigated in a ROC curve. RESULTS:Nine hundred and ninety-one patients were monitored in the first 3h after CEA. Two percent developed ischaemic cerebral complications. Univariate analysis revealed statistically significant associations between ischaemic cerebral complications and both gender and MES, but not age. In a multivariate analysis, > or =8 MES/h showed a statistically significant relationship with cerebral complications (OR 8.1, 95% CI 1.8-36), in contrast to gender (OR 2.2, 95% CI 0.9-5.5). The ROC curve yielded an AUC of 0.83 for monitoring of MES. CONCLUSIONS:These results support the use of TCD monitoring for MES shortly after CEA in order to identify patients at risk of developing ischaemic cerebral complications.
Difference in Transcranial Doppler Velocity and Patient Age between Proximal and Distal Middle Cerebral Artery Vasospasms after Aneurysmal Subarachnoid Hemorrhage.
Kohama Misaki,Sugiyama Shinichiro,Sato Kenichi,Endo Hidenori,Niizuma Kuniyasu,Endo Toshiki,Ohta Makoto,Matsumoto Yasushi,Fujimura Miki,Tominaga Teiji
Cerebrovascular diseases extra
BACKGROUND:Transcranial Doppler (TCD) is used to monitor cerebral vasospasm after subarachnoid hemorrhage (SAH), but its diagnostic ability is reported to be limited. Therefore, the purpose of this study was to investigate the relationship between the diagnosability of TCD and the localization of the vasospasm. METHODS:This retrospective study included 20 patients who presented with symptomatic vasospasm after SAH. All 20 patients underwent daily TCD examinations and cerebral angiography after the onset of delayed cerebral ischemia. We defined positive findings on TCD as a maximum flow velocity >200 cm/s or as a mean flow velocity >120 cm/s at the horizontal part of the middle cerebral artery (MCA). We also examined the site of vasospasm on cerebral angiography. RESULTS:Fourteen patients had true-positive findings on TCD examination, and cerebral angiography showed diffuse vasospasm involving the horizontal segment of the MCA. However, 6 patients had false-negative findings on TCD examination, and cerebral angiography showed vasospasm localized at the distal part of the MCA (the insular and/or cortical segments). The patients with proximal vasospasm were significantly younger than those with distal vasospasm. Blood flow velocity at initial TCD and the increase in velocity at the onset of vasospasm were lower and smaller, respectively, in the distal vasospasm group. CONCLUSIONS:In patients with cerebral vasospasm localized at the distal part of the MCA, flow velocity at the horizontal segment of the MCA did not increase to the level we defined as positive. To avoid such false negatives, a slight increase in velocity on TCD should be considered as positive in distal vasospasm cases, especially in older patients.
TCD systolic spikes in a malignant MCA infarct.
Perez-Nellar Jesus,Scherle Claudio,Machado Calixto
INTRODUCTION:Malignant MCA infarction results in significant space occupying effect and intracranial pressure (ICP) increment. Due to the high mortality rate in such patients, the term malignant MCA infarction was coined. METHODS:We studied a patient who developed a sudden onset of slurred speech, right hemiplegia, and decreased level of arousal. Two days later CT scan showed a massive cerebral infarct, involving the left MCA territory. RESULTS:A transcranial Doppler exam showed a normal flow pattern in the right hemisphere, but in the left hemisphere systolic spikes without diastolic flow were observed in internal carotid artery, anterior cerebral artery, as well as in the MCA. CONCLUSIONS:The pathophysiologic mechanisms leading to BD might asymmetrically begin in cerebral hemispheres in malignant MCA infarcts.
Accuracy of Transcranial Doppler Ultrasound Compared with Magnetic Resonance Angiography in the Diagnosis of Intracranial Artery Stenosis.
Jaiswal Sandip Kumar,Fu-Ling Yan,Gu Lihua,Lico Renardo,Changyong Fu,Paula Angela
Journal of neurosciences in rural practice
One of the most common causes of acute cerebral infarction (ACI) is intracranial artery stenosis (ICAS). The goal of our study was to evaluate the accuracy of transcranial Doppler (TCD) compared with magnetic resonance angiography (MRA) for diagnosing ICAS in patients with ACI. Consecutive patients presenting with ACI to the neurology department underwent both MRA and TCD examination within 6 hours of difference. To calculate the agreement between the results of MRA and TCD, kappa coefficient test was used. Sensitivity, specificity, and positive and negative TCD predictive values have been calculated in comparison with MRA. A total of 115 patients was included. There were 77 males (66.95%) and 38 females (33.04%). The mean age of patients was 68.32 ± 10.66 years (range 29-80). The agreement between TCD and MRA in detecting stenosis was 0.56 for anterior circulation artery (ACA), and 0.40 for posterior circulation artery. For the detection of ICAS, sensitivity, specificity, positive predictive value, and negative predictive values were 85.9, 90.0, 98.2, and 50.0% for anterior cerebral artery and 73.5, 86.7, 96.2, and 40.0% for posterior cerebral artery, respectively. Moderate agreement of anterior circulation stenosis and fair agreement for posterior circulation stenosis was found between TCD and MRA in the evaluation of ICAS. In anterior circulation, the diagnostic accuracy of TCD is higher compared with the posterior circulation.
The quest for early predictors of stroke evolution: can TCD be a guiding light?
Baracchini C,Manara R,Ermani M,Meneghetti G
BACKGROUND AND PURPOSE:The present study aimed at evaluating the prognostic value of transcranial Doppler ultrasonography (TCD) in the acute phase of ischemic stroke, when major therapeutic decisions must be made. METHODS:Seventy-three patients with a first-ever ischemic hemispheric stroke underwent neurological assessment according to the Unified Neurological Stroke Scale, clinical subgrouping according to the criteria of Bamford, CT scan, cervical duplex sonography, and TCD, all within 12 hours from stroke onset. TCD was repeated on days 2 and 7. Patients were followed for 90 days, during which we calculated the fatality rate and then assessed clinical outcome. RESULTS:Emergency TCD revealed middle cerebral artery (MCA) no-flow in 24 cases and MCA asymmetry in 30 subjects. Serial TCD showed early (<24 hours) MCA recanalization in 6 patients. After 90 days, no patient with MCA occlusion at admission was autonomous, while 17 of 19 patients (89.5%) with a normal baseline TCD were independent. The fatality rate at 3 months was 21% but was 46% in patients with MCA occlusion and 61% in patients without signs of early MCA recanalization. Total anterior circulation infarct and abnormal TCD were significantly correlated (P:<0.001) with higher mortality rate and worse outcome (Barthel Index score </=60), whereas early CT ischemic signs and severe carotid disease were not. Furthermore, TCD identified within the total anterior circulation infarct subgroup 2 prognostic clusters according to MCA patency at admission (P:<0.001). Logistic regression selected normal baseline TCD as an independent predictor of good long-term outcome and MCA no-flow as an independent predictor of disability or death. CONCLUSIONS:TCD findings play an important role in the early prognosis of anterior circulation stroke, providing possible guidance for therapeutic interventions.
Sharma Vijay K,Wong Ka Sing,Alexandrov Andrei V
Frontiers of neurology and neuroscience
Transcranial Doppler ultrasonography (TCD) is the only diagnostic modality that provides a reliable evaluation of intracranial blood flow patterns in real-time. The physiological information obtained from TCD is complementary to the anatomical details obtained from other neuroimaging modalities. TCD is relatively cheap, can be performed bedside, and allows monitoring in acute emergency settings. TCD criteria for intracranial stenosis have been validated against various forms of angiographic studies and serve as reliable tools for screening, diagnostic as well as follow up purposes. TCD findings of intracranial stenosis have acceptable accuracy parameters for anterior as well as posterior circulation. Extended applications of TCD, especially emboli monitoring and assessment of vasomotor reactivity, provide important information about the pathophysiology of cerebrovascular ischemia and risk stratification. Therefore, TCD has become an integral component of the armamentarium of stroke neurologists for understanding stroke etiopathogenesis, planning and monitoring definitive treatment and determining the prognosis. We present the basic principles of TCD, techniques of test performance, diagnostic methods as well as some of the advanced applications of TCD in patients with intracranial stenosis.
Hakimi Ryan,Alexandrov Andrei V,Garami Zsolt
Transcranial Doppler ultrasonography (TCD) is a noninvasive, bedside, portable tool for assessment of cerebral hemodynamics. Modern TCD head frames allow continuous hands-free emboli detection for risk stratification and assessment of treatment efficacy in several cardiovascular diseases. Identifying a focal stenosis, arterial occlusion, and monitoring the treatment effect of intravenous tissue plasminogen activator can easily be accomplished by assessing TCD waveforms and determining prestenotic and poststenotic mean flow velocities. TCD is an excellent screening tool for vasospasm in aneurysmal subarachnoid hemorrhage. The use of intraoperative TCD during carotid endarterectomy and stenting allows optimal intraoperative hemodynamic management. Other applications are also discussed.
Vasospasm on transcranial Doppler is predictive of delayed cerebral ischemia in aneurysmal subarachnoid hemorrhage: a systematic review and meta-analysis.
Kumar Gyanendra,Shahripour Reza Bavarsad,Harrigan Mark R
Journal of neurosurgery
OBJECT The impact of transcranial Doppler (TCD) ultrasonography evidence of vasospasm on patient-centered clinical outcomes following aneurysmal subarachnoid hemorrhage (aSAH) is unknown. Vasospasm is known to lead to delayed cerebral ischemia (DCI) and poor outcomes. This systematic review and meta-analysis evaluates the predictive value of vasospasm on DCI, as diagnosed on TCD. METHODS MEDLINE, Scopus, the Cochrane trial register, and clinicaltrials.gov were searched through September 2014 using key words and the terms "subarachnoid hemorrhage," "aneurysm," "aneurysmal," "cerebral vasospasm," "vasospasm," "transcranial Doppler," and "TCD." Sensitivities, specificities, and positive and negative predictive values were pooled by a DerSimonian and Laird random-effects model. RESULTS Seventeen studies (n = 2870 patients) met inclusion criteria. The amount of variance attributable to heterogeneity was significant (I(2) > 50%) for all syntheses. No studies reported the impact of TCD evidence of vasospasm on functional outcome or mortality. TCD evidence of vasospasm was found to be highly predictive of DCI. Pooled estimates for TCD diagnosis of vasospasm (for DCI) were sensitivity 90% (95% confidence interval [CI] 77%-96%), specificity 71% (95% CI 51%-84%), positive predictive value 57% (95% CI 38%-71%), and negative predictive value 92% (95% CI 83%-96%). CONCLUSIONS TCD evidence of vasospasm is predictive of DCI with high accuracy. Although high sensitivity and negative predictive value make TCD an ideal monitoring device, it is not a mandated standard of care in aSAH due to the paucity of evidence on clinically relevant outcomes, despite recommendation by national guidelines. High-quality randomized trials evaluating the impact of TCD monitoring on patient-centered and physician-relevant outcomes are needed.
Impact of Transcranial Doppler Ultrasound on Logistics and Outcomes in Stroke Thrombolysis: Results From the SITS-ISTR.
Mazya Michael V,Ahmed Niaz,Azevedo Elsa,Davalos Antoni,Dorado Laura,Karlinski Michal,Lorenzano Svetlana,Neumann Jiří,Toni Danilo,Moreira Tiago P,
BACKGROUND AND PURPOSE:Diagnostic transcranial Doppler ultrasound (TCD) is commonly used in patients with acute stroke before or during treatment with intravenous thrombolysis (IVT). We aimed to assess how much TCD delays IVT initiation and whether TCD influences outcomes. METHODS:We analyzed data from the SITS-ISTR (Safe Implementation of Thrombolysis in Stroke-International Stroke Thrombolysis Register) collected from December 2002 to December 2011. Outcomes were door-to-needle time, symptomatic intracerebral hemorrhage, functional outcome per the modified Rankin Scale, and mortality at 3 months. RESULTS:In hospitals performing any TCD pre-IVT, 1701 of 11 265 patients (15%) had TCD before IVT initiation. Door-to-needle time was higher in patients with pre-IVT TCD (74 versus 60 minutes; <0.001). At hospitals performing any TCD during IVT infusion, of 9044 patients with IVT, 747 were examined with TCD during IVT. No treatment delay was seen with TCD during IVT. After multivariate adjustment, TCD during IVT was independently associated with modestly increased excellent functional outcome (modified Rankin Scale, 0-1; adjusted odds ratio, 1.28; 95% confidence interval, 1.06-1.55; =0.012) and lower mortality (adjusted odds ratio, 0.73; 95% confidence interval, 0.55-0.95; =0.022). CONCLUSIONS:We recommend that TCD, if performed, should be done during IVT infusion, to avoid treatment delay. The association of hyperacute TCD with beneficial outcomes suggests potential impact on patient management, which warrants further study.
Relationships of transcranial blood flow Doppler parameters with major vascular risk factors: TCD study in patients with a recent TIA or nondisabling ischemic stroke.
Wijnhoud Annemarie D,Koudstaal Peter J,Dippel Diederik W J
Journal of clinical ultrasound : JCU
PURPOSE:The relationship between intracranial vascular disease and cardiovascular risk factors such as smoking, hypertension, diabetes mellitus, and total serum cholesterol in patients with recent cerebral ischemia is not well established. We used transcranial Doppler (TCD) sonography tests as parameters of intracranial vascular disease and investigated the relationship between these parameters and conventional cardiovascular risk factors. METHODS:We prospectively studied 598 patients with a minor ischemic stroke or transient ischemic attack (TIA). In all patients, flow velocities in the left and right middle cerebral artery (MCA), and cerebrovascular reactivity to CO2 were measured by means of TCD sonography. Student's t-test and linear regression analysis were used to determine the relationship between the baseline characteristics, vascular risk factors, and TCD parameters. RESULTS:After adjustment for other vascular risk factors, a statistically significant relationship with mean flow velocity in the MCA was found for age (3.5 cm/s/10 years of age; 95% CI, 2.5-4.5 cm/s/10 years of age; p < 0.0001), sex (-2.9 cm/s for male sex; 95% CI, -5.5 to -0.3 cm/s; p = 0.03), diabetes (5.6 cm/s for diabetics; 95% CI, 2.1-9.1 cm/s; p = 0.002), and total serum cholesterol (2.4 cm/s per mmol increase in total serum cholesterol; 95% CI, 1.4-3.5 cm/s; p < 0.0001). Total serum cholesterol and hypertension were related to cerebrovascular reactivity to CO2. CONCLUSIONS:Cerebral flow velocity is influenced by multiple interacting factors. Results of TCD investigations should be adjusted for age, sex, diabetes, and cholesterol when used for diagnostic or prognostic purposes.
The Role of Transcranial Doppler in Traumatic Brain Injury: A Systemic Review and Meta-Analysis.
Fatima Nida,Shuaib Ashfaq,Chughtai Talat Saeed,Ayyad Ali,Saqqur Maher
Asian journal of neurosurgery
To evaluate whether transcranial Doppler (TCD) monitoring plays a role as a prognostic indicator, by being both a diagnostic as well as a monitoring tool for increased intracranial pressure and cerebral vasospasm (VSP), in traumatic brain injury (TBI). Electronic databases and gray literature (unpublished articles) were searched under different MeSH terms from 1990 to the present. Randomized control trials, case-control studies, and prospective cohort studies on TCD in TBI (>18 years old). Clinical outcome measures included Glasgow Coma Outcome Scale (GCOS) and Extended GCOS and mortality. Data were extracted to Review Manager Software. Twenty-five articles that met the inclusion criteria were retrieved and analyzed. Ultimately, five studies were included in our meta-analysis, which revealed that patients with TBI with abnormal TCD (mean flow velocity [MFV] >120 cm/sec or MFV <35 cm/sec and Pulsatility Index >1.2) have a >3-fold higher likelihood of having poor clinical outcome in comparison to patients with TBI and normal TCD monitoring (odds ratio [OR]: 3.87; 95% confidence interval [CI]: 2.97-5.04; < 0.00001). Subgroup analysis revealed that abnormal TCD has a 9-fold higher likelihood of mortality (OR: 9.96; 95% CI: 4.41-22.47; < 0.00001). Further, subgroup analysis based on TCD findings revealed that the presence of hypoperfusion on TCD (middle cerebral artery [MCA] <35 cm/s) is associated with a three-fold higher likelihood of having poor functional outcome (OR: 3.72; 95% CI: 1.97-7.0; < 0.0001). The presence of VSP (MCA >120 cm/s) is associated with three-fold higher likelihood of poor functional outcome (OR: 3.64; 95% CI: 1.55-8.52; = 0.003). TCD is an evolving diagnostic tool that might play a role in determining the prognosis of patients with TBI. Further prospective study is needed to prove the role of TCD in TBI.
Brain ultrasound for diagnosis and prognosis in the neurological intensive care unit: a mini review for current development.
Zhu Haomeng,Geng Xiaokun,Rajah Gary B,Fu Paul,Du Huishan
Transcranial doppler ultrasonography (TCD) is one of the few tools in the Neurological Intensive Care Unit (NICU) that allows for real-time monitoring of cerebral blood flow while also being non-invasive. This review examines the current use of TCD monitoring in the NICU. We completed a literature review using Google Scholar and Pubmed. Relevant articles were included in this review. The role of TCD in the NICU continues to evolve since its infancy in the 1980s. TCD use is now standard of care of for some neurological maladies. The significant advantages of TCD include convenience of use, non-invasive nature, bedside operation, high accuracy, and absence of interference from external factors such as temperature and sedatives. This review examines the current use of TCD monitoring in the NICU. Through review and continued development of similar non invasive technologies NICU care continues to innovate and evolve. TCD: Transcranial Doppler.
High-risk asymptomatic carotid stenosis: ulceration on 3D ultrasound vs TCD microemboli.
Madani A,Beletsky V,Tamayo A,Munoz C,Spence J D
OBJECTIVE:We compared microemboli on transcranial Doppler (TCD) with carotid ulcerations on 3D ultrasound (US) as an additional method for identifying the small proportion of patients with asymptomatic carotid stenosis (ACS) who can benefit from revascularization such as endarterectomy or stenting. METHODS:Patients with ACS (n = 253) with carotid stenosis >60% by Doppler ultrasound were studied prospectively with TCD embolus detection and 3D US to detect ulcers (the total number of ulcers in both internal carotids) and followed for 3 years. RESULTS:Mean age was 69.66 (SD 8.51) years; 11 (4%) had ≥3 ulcers (Ulcer 3), 11 (6%) had microemboli, and 25 (10%) had microemboli or ≥3 ulcers. Ulcer 3 patients were more likely to have a stroke or death in 3 years (18% vs 2%; p = 0.03), regardless of the side on which the ulcers were found. The 3-year risk of stroke or death was 20% with microemboli vs 2% without (p = 0.003). The annual rate of ipsilateral stroke was 0.8%. CONCLUSION:Adding 3D US detection of ulcers doubles (to 10%) the proportion of patients with ACS who may benefit from endarterectomy or stenting. However, until 3-year event rates of stroke or death with endarterectomy or stenting reach <2%, 90% of patients with ACS would be better treated medically until they develop symptoms, ulcers, or emboli.
The prognostic value of pulsatility index, flow velocity, and their ratio, measured with TCD ultrasound, in patients with a recent TIA or ischemic stroke.
Wijnhoud A D,Koudstaal P J,Dippel D W J
Acta neurologica Scandinavica
BACKGROUND - Increased flow velocities, and combinations of low mean flow velocity (MFV) and a high pulsatility index (PI) are associated with intracranial arterial disease. We investigated the association of MFV and the ratio of PI and MFV (PI-MFV ratio) in the middle cerebral artery (MCA) with recurrence of vascular events in patients with a transient ischemic attack (TIA) or minor ischemic stroke. METHODS - Five hundred and ninety-eight consecutive patients underwent TCD investigation. Outcome events were fatal or non-fatal stroke and the composite of stroke, myocardial infarction, or vascular death (major vascular events). Hazard ratios (HR) were estimated with Cox proportional hazards multiple regression method, adjusted for age, gender, and vascular risk factors. RESULTS - TCD registration was successful in 489 patients. Mean follow-up was 2.1 years. Cumulative incidence was 9% for all stroke and 12% for major vascular events. MFV over 60.5 cm/s increased the risk for both stroke (HR 2.8; 95% CI: 1.3-6.0) and major vascular events (HR 2.6; 95% CI: 1.3-5.0). Each unit increase in PI-MFV ratio was associated with a HR 2.8 (95% CI: 1.7-4.8) for stroke and HR 2.2 (95% CI: 1.3-3.6) for major vascular events. CONCLUSION - In patients with a TIA or non-disabling ischemic stroke, MFV and the PI-MFV ratio in the MCA are independent prognostic factors for recurrent vascular events.
The correlation between admission blood glucose and intravenous rt-PA-induced arterial recanalization in acute ischemic stroke: a multi-centre TCD study.
Saqqur Maher,Shuaib Ashfaq,Alexandrov Andrei V,Sebastian Joseph,Khan Khurshid,Uchino Ken
International journal of stroke : official journal of the International Stroke Society
BACKGROUND:The relationship between hyperglycemia and arterial recanalization following intravenous recombinant tissue-plasminogen activator treatment in acute ischemic stroke is not well understood. AIM:We aimed to evaluate the effects of hyperglycemia in thrombolysed ischemic stroke patients on recanalization rate and clinical outcome. METHODS:We studied 348 (231 subjects from the CLOTBUST databank and 117 subjects from the CLOTBUST trial phase II) with documented intracranial artery occlusion treated with intravenous recombinant tissue-plasminogen activator. Serum glucose was determined at baseline before intravenous recombinant tissue-plasminogen activator administration. Hyperglycemia was defined as a glucose level ≥140 mg/dl (7·7 mmol/l). Transcranial Doppler findings were interpreted using the thrombolysis in brain ischemia flow grading system as persistent arterial occlusion, re-occlusion or complete recanalization. Poor clinical outcome was defined by modified Rankin score > 2 at three-months. RESULTS:At baseline, 138 patients (37·4%) were hyperglycemic and 210 patients (56·9%) normoglycemic. Baseline characteristics based on glucose ≥ 140 (7·7 mmol/l) or less 140: age (70·0 ± 12·4 vs. 67·3 ± 14·1, P = 0·065), baseline National Institutes of Health Stroke Scale (17·0 ± 5·5 vs. 15·8 ± 5·5, P = 0·054), time to recombinant tissue-plasminogen activator (141·4 ± 69·1 vs. 145·3 ± 48·4 mins, P = 0·56), and history of diabetes mellitus [60/138 (43·5%) vs. 22/210 (10·5%), P < 0·001]). Patients with hyperglycemia have a higher rate of persisting occlusion [72/138 (52·2%) vs. 66/210 (31·4%)] and less rate of complete recanalization [34/138 (24·6%) vs. 82/210 (39%), P < 0·001]. Median time to recanalization in patients with severe hyperglycemia (glucose ≥ 200) (11 mmol/l) and glucose <200 was 163 ± 79 and 131 ± 90 mins, respectively (P = 0·045). Sixteen patients (11·6%) in the hyperglycemic group and 12 (5·7%) in the normoglycemic group had symptomatic intracerebral hemorrhage (P = 0·049). Seventy-eight patients (69%) in the hyperglycemia group and 72 patients (41·6%) in the normoglycemic group had poor clinical outcome (three-month modified Rankin score > 2) (P ≤ 0·001). After adjusting for stroke risk factors, patients with hyperglycemia were more likely to have poor clinical outcome (three-month modified Rankin score > 2) (adjusted odds ratio = 2·22, 95% confidence interval: 1·2-4·11, P = 0·011) and low complete recanalization rate (adjusted odds ratio: 0·5, confidence interval: 0·3-0·92, P = 0·025) with trend of increase risk of symptomatic intracerebral hemorrhage (adjusted odds ratio: 2·07, confidence interval:0·8-5·1, P = 0·114). There was no association between baseline glucose as a continuous variable and poor clinical outcome, but there was with the complete recanalization's rate. CONCLUSION:Hyperglycemia is associated with low rate of complete recanalization and poor clinical outcome in intravenous recombinant tissue-plasminogen activator-treated patients. Further studies are needed to evaluate whether lowering hyperglycemia is beneficial in the management of acute stroke patients.
Use of Transcranial Doppler (TCD) ultrasound in the Neurocritical Care Unit.
Kalanuria Atul,Nyquist Paul A,Armonda Rocco A,Razumovsky Alexander
Neurosurgery clinics of North America
Transcranial Doppler (TCD) is a portable device that uses a handheld 2-MHz transducer. It is most commonly used in subarachnoid hemorrhage where cerebral blood flow velocities in major intracranial blood vessels are measured to detect vasospasm in the first 2 to 3 weeks. TCD is used to detect vasospasm in traumatic brain injury and post-tumor resection, measurement of cerebral autoregulation and cerebrovascular reactivity, diagnosis of acute arterial occlusions in stroke, screening for patent foramen ovale and monitoring of emboli. It can be used to detect abnormally high intracranial pressure and for confirmation of total cerebral circulatory arrest in brain death.
Effect of human albumin on TCD vasospasm, DCI, and cerebral infarction in subarachnoid hemorrhage: the ALISAH study.
Suarez Jose I,Martin R H,Calvillo E,Bershad E M,Venkatasubba Rao C P
Acta neurochirurgica. Supplement
BACKGROUND AND PURPOSE:The neuroprotective effects of human albumin have been studied in animal models of stroke and in humans with various intracranial disorders. We investigated the effect of 25 % human albumin (ALB) on mean cerebral blood flow velocities (MCBFV), delayed cerebral ischemia (DCI), and cerebral infarction. METHODS:We studied patients from the Albumin in Subarachnoid Hemorrhage (ALISAH) pilot clinical trial. We collected data on MCBFV as measured by transcranial Doppler ultrasound (TCD), incidence of DCI, and cerebral infarctions on head computed tomography (CT) scan at 90 days. RESULTS:TCD showed vasospasm in 75 % (n = 15), 55 % (n = 11), and 29 % (n = 2) of subjects in dosage tiers 1, 2, and 3, respectively. DCI was present in 20 % (n = 4), 15 % (n = 3), and 14 % (n = 1) of subjects in dosage tiers 1, 2, and 3, respectively. Cerebral infarctions were seen in 45 % (5 of 9), 27 % (3 of 18), and 25 % (1 of 4) of subjects who had follow-up head CT scans in dosage tiers 1, 2, and 3, respectively. CONCLUSIONS:Higher dosages of ALB were associated with a lower incidence of TCD vasospasm, DCI, and cerebral infarction at 90 days in a dose-dependent manner.
Post-intervention TCD examination may be useful to predict outcome in acute ischemic stroke patients with successful intra-arterial intervention.
Aoki Junya,Raber Larry N,Katzan Irene L,Hussain Muhammad Shazam,Hui Ferdinand K,Uchino Ken
Journal of the neurological sciences
BACKGROUND AND PURPOSE:Some acute stoke patients have a poor outcome despite successful arterial recanalization. We hypothesized that transcranial Doppler (TCD) findings from the rescued artery might predict poor outcome in patients with recanalization. METHODS:Acute stroke patients treated with internal carotid artery or middle cerebral artery (MCA) occlusions with follow-up TCD examination after intra-arterial (IA) intervention were retrospectively analyzed. Only patients with at least a Thrombolysis In Myocardial Infarction (TIMI) flow grade ≥ 2 in the MCA territory were included. Mean flow velocity (MFV) and pulsatility index (PI) of the rescued MCA were obtained by TCD. Poor clinical outcome was defined as in-hospital death or decompressive craniectomy. RESULTS:Among 50 patients, there were 8 (16%) in the Poor Outcome group and 42 (84%) in the Non-poor Outcome group. TCD was conducted at a median of 1 day (interquartile range, 1-1) after IA therapy. Although MCA MFV was not different between the two groups, MCA PI was significantly higher in the Poor Outcome group than in the Non-poor Outcome group (1.3 [1.1-1.7] vs. 0.8 [0.7-1.1], p = 0.002). After adjusting for the National Institutes of Health Stroke Scale score on admission, the Alberta Stroke Programme Early Computed Tomography score, a past history of coronary artery disease and the Thrombolysis In Brain Ischemia grade, MCA PI was an independent predictor of poor outcome (odds ratio: 1.71, 95% confidence interval: 1.10-2.66, p = 0.017). CONCLUSION:Follow-up TCD examination after IA intervention in acute stroke patients may predict poor outcome beyond angiographic residual TIMI flow.
Carotid intraplaque hemorrhage on vessel wall MRI does not correlate with TCD emboli monitoring in patients with recently symptomatic carotid atherosclerosis.
de Havenon Adam,Tirschwell David,Majersik Jennifer J,McNally Scott,Stoddard Gregory,Moore Anne,Mossa-Basha Mahmud
The neuroradiology journal
Background Carotid intraplaque hemorrhage (IPH) seen on vessel wall MRI is associated with an increased risk of stroke or transient ischemic attack, as are microembolic signals (MES) detected by transcranial Doppler (TCD). We sought to examine the association between IPH and MES in acute stroke patients with symptomatic carotid atherosclerosis. Methods Through a retrospective chart review, we included patients from 2011 to 2013 with acute ischemic stroke due to carotid atherosclerosis of varying stenosis who had both 3D volumetric MRI of the neck and TCD emboli monitoring. Results Twenty-four patients met the inclusion criteria. Mean time from stroke to MRI was 1.4 ± 1.9 days and to TCD was 2.6 ± 2.4 days. MES was seen in 10 patients (42%) and IPH was present in seven patients (29%), but we did not find a relationship between MES and IPH ( p = 0.64). Conclusion In patients with recent acute ischemic stroke attributed to carotid atherosclerosis, we did not detect an association between the presence of IPH and MES. While this small study may be underpowered, an alternate explanation is that MES and IPH reflect vulnerable carotid atherosclerosis through different mechanisms. This untested concept warrants prospective study in a larger cohort.
Transcranial Doppler and Transcranial Color Duplex in Defining Collateral Cerebral Blood Flow.
Saqqur Maher,Khan Khurshid,Derksen Carol,Alexandrov Andrei,Shuaib Ashfaq
Journal of neuroimaging : official journal of the American Society of Neuroimaging
In an acute stroke setting, transcranial Doppler (TCD) and transcranial color-coded duplex (TCCD) have an important diagnostic utility in the monitoring of an arterial occlusion and microemboli detection. In addition, TCD has proven to be a very useful tool in the detection and progression of cerebral vasospasm in patients with subarachnoid hemorrhage. TCD/TCCD may have an important role in defining collateral blood flow (CF) in stroke patients. It is a noninvasive technique and can be utilized repeatedly allowing for changes in the blood flow dynamics as treatment is delivered. In this review, we outlined the evolving role of TCD/TCCD in defining CF in patients with an acute ischemic stroke, predicting clinical outcome and monitoring the treatment's efficacy of the CF augmentation.
Abnormal Blood Flow on Transcranial Duplex Sonography Predicts Poor Outcome After Stroke Thrombectomy.
Kneihsl Markus,Niederkorn Kurt,Deutschmann Hannes,Enzinger Christian,Poltrum Birgit,Horner Susanna,Thaler Daniela,Kraner Julia,Fandler Simon,Colonna Isabella,Fazekas Franz,Gattringer Thomas
Background and Purpose- Hemodynamic changes following mechanical thrombectomy for large vessel occlusion stroke could be associated with complications and might affect prognosis. We investigated postinterventional middle cerebral artery blood flow on transcranial duplex sonography (TCD) and its prognostic value for anterior large vessel occlusion stroke patients. Methods- We identified all ischemic stroke patients who had undergone mechanical thrombectomy for anterior circulation large vessel occlusion from 2010 onwards. Postinterventional middle cerebral artery flow was graded according to the sonographic Thrombolysis in Brain Ischemia score and related to patient outcome stratified by the angiographic Thrombolysis in Cerebral Infarction reperfusion status. Results- Of 215 large vessel occlusion stroke patients, 193 patients (90%) showed successful angiographic recanalization (Thrombolysis in Cerebral Infarction grade 2b-3). Of those, 69 (36%) patients had abnormal sonographic middle cerebral artery blood flow (Thrombolysis in Brain Ischemia grade 0-4) within 72 hours after mechanical thrombectomy, which was an independent predictor for poor 90-day outcome. Conclusions- TCD indicates abnormal middle cerebral artery hemodynamics in a substantial proportion of patients with angiographically defined successful mechanical thrombectomy of the anterior cerebral circulation. Such changes are associated with poor short-term outcome.
Decreased Flow Velocity with Transcranial Color-Coded Duplex Sonography Correlates with Delayed Cerebral Ischemia due to Peripheral Vasospasm of the Middle Cerebral Artery.
Sadahiro Hirokazu,Shirao Satoshi,Yoneda Hiroshi,Ishihara Hideyuki,Oku Takayuki,Inamura Akinori,Yamane Akiko,Sugimoto Kazutaka,Fujiyama Yuichi,Suzuki Michiyasu
Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association
BACKGROUND AND OBJECTIVE:Despite intensive therapy, vasospasm remains a major cause of delayed cerebral ischemia (DCI) in worsening patient outcome after aneurysmal subarachnoid hemorrhage (aSAH). Transcranial Doppler (TCD) and transcranial color-coded duplex sonography (TCCS) are noninvasive modalities that can be used to assess vasospasm. However, high flow velocity does not always reflect DCI. The purpose of this study was to investigate the utility of TCD/TCCS in decreasing permanent neurological deficits. METHODS:We retrospectively enrolled patients with aSAH who were treated within 72 hours after onset. TCCS was performed every day from days 4 to 14. Peak systolic velocity (PSV), mean velocity (MV), and pulsatility index were recorded and compared between DCI and non-DCI patients. In patients with DCI, endovascular therapy was administered to improve vasospasm, which led to a documented change in velocity. RESULTS:Of the 73 patients, 7 (9.6%) exhibited DCI. In 5 of the 7 patients, DCI was caused by vasospasm of M2 or the more peripheral middle cerebral artery (MCA), and the PSV and MV of the DCI group were lower than those of the non-DCI group after day 7. Intra-arterial vasodilator therapy (IAVT) was performed for all patients with DCI immediately to increase the flow volume by the next day. CONCLUSIONS:Increasing flow velocity cannot always reveal vasospasm excluding M1. In patients with vasospasm of M2 or more distal arteries, decreasing flow velocity might be suggestive of DCI. IAVT led to increases in the flow velocity through expansion of the peripheral MCA.
[Diagnostic, prognostic and therapeutic implications of transcranial color-coded duplex sonography in acute ischemic stroke: TIBI and COGIF scores validation].
Sobrino-Garcia P,Garcia-Pastor A,Garcia-Arratibel A,Dominguez-Rubio R,Rodriguez-Cruz P M,Iglesias-Mohedano A M,Diaz-Otero F,Vazquez-Alen P,Fernandez-Bullido Y,Villanueva-Osorio J A,Gil-Nunez A
Revista de neurologia
AIM:To describe the information provided by transcranial color-coded duplex (TCCD) sonography for therapeutic decision-making in patients with acute ischemic stroke and to analyze the relationship between TCCD findings and the severity and prognosis of stroke. PATIENTS AND METHODS:TCCD performed within the six first hours after an acute ischemic stroke were analyzed in our institution. The presence of an arterial occlusion and its location were collected using TIBI (Thrombolysis in Brain Ischemia) and COGIF (Consensus on Grading Intracranial Flow Obstruction) criteria. Arterial recanalization within 24 hours after stroke was determined using TIBI and COGIF criteria. Favorable functional outcome was defined as a modified Rankin scale from 0 to 2 at three months. RESULTS:TCCD was performed in 104 patients, 85 were treated with intravenous thrombolysis. Arterial occlusion was detected in 79.8% of patients. The detection of arterial occlusion with TCCD allowed the selection for endovascular treatment in 23.1% of patients. Arterial occlusion was associated with a higher severity of stroke. Recanalization was detected in 44.1% using TIBI and 45.8% according to COGIF criteria. 80.8% of recanalized patients and only 39.5% of not recanalized had a favorable functional outcome at three months. Recanalization rate depended on the location of arterial occlusion. CONCLUSION:TCCD is a useful technique for the detection and location of arterial occlusion. It provides valuable prognostic information and allows selecting patients for endovascular recanalizing therapies. TIBI and COGIF scores provide a comparable information.
Value of transcranial Doppler, perfusion-CT and neurological evaluation to forecast secondary ischemia after aneurysmal SAH.
Westermaier Thomas,Pham Mirko,Stetter Christian,Willner Nadine,Solymosi Laszlo,Ernestus Ralf-Ingo,Vince Giles Hamilton,Kunze Ekkehard
INTRODUCTION:This study was conducted to prospectively evaluate the diagnostic value of detailed neurological evaluation, transcranial Doppler sonography (TCD) and Perfusion-CT (PCT) to predict delayed vasospasm (DV) and delayed cerebral infarction (DCI) within the following 3 days in patients with aneurysmal subarachnoid hemorrhage (SAH). METHODS:A total of 61 patients with aneurysmal SAH were included in the study. All patients were amenable for neurological evaluation throughout the critical phase to develop secondary ischemia after SAH. The neurological status was assessed three times a day according to a detailed examination protocol. Mean flow velocities (MFV) in intracranial vessel trunks were measured daily by TCD. Native CT and PCT were routinely acquired at 3-day intervals and, in addition, whenever it was thought to be of diagnostic relevance. The predictive values of abnormal PCT and accelerations in TCD (MFV > 140 cm/s) to detect angiographic DV and DCI within the following 2 days were calculated and compared to the predictive value of delayed ischemic neurological deficits (DIND). RESULTS:The accuracy of TCD and PCT to predict DV or DCI was 0.65 and 0.63, respectively. In comparison, DIND predicted DV or DCI with an accuracy of 0.96. Pathological PCT findings had a higher sensitivity (0.93) and negative predictive value (0.98) than TCD (0.81 and 0.96). CONCLUSION:Neurological assessment at close intervals is the most accurate parameter to detect DV and DCI in the following 3 days. However, DIND may not be reversible. The routine acquisition of PCT in addition to daily TCD examinations seems reasonable, particularly in patients who are not amenable to a detailed neurological examination since it has a higher sensitivity and negative predictive value than TCD and leaves a lower number of undetected cases of vasospasm and infarction.
Transcranial Doppler sonography for detecting stenosis or occlusion of intracranial arteries in people with acute ischaemic stroke.
Mattioni Alessia,Cenciarelli Silvia,Eusebi Paolo,Brazzelli Miriam,Mazzoli Tatiana,Del Sette Massimo,Gandolfo Carlo,Marinoni Marinella,Finocchi Cinzia,Saia Valentina,Ricci Stefano
The Cochrane database of systematic reviews
BACKGROUND:An occlusion or stenosis of intracranial large arteries can be detected in the acute phase of ischaemic stroke in about 42% of patients. The approved therapies for acute ischaemic stroke are thrombolysis with intravenous recombinant tissue plasminogen activator (rt-PA), and mechanical thrombectomy; both aim to recanalise an occluded intracranial artery. The reference standard for the diagnosis of intracranial stenosis and occlusion is intra-arterial angiography (IA) and, recently, computed tomography angiography (CTA) and magnetic resonance angiography (MRA), or contrast-enhanced MRA. Transcranial Doppler (TCD) and transcranial colour Doppler (TCCD) are useful, rapid, noninvasive tools for the assessment of intracranial large arteries pathology. Due to the current lack of consensus regarding the use of TCD and TCCD in clinical practice, we systematically reviewed the literature for studies assessing the diagnostic accuracy of these techniques compared with intra-arterial IA, CTA, and MRA for the detection of intracranial stenosis and occlusion in people presenting with symptoms of ischaemic stroke. OBJECTIVES:To assess the diagnostic accuracy of TCD and TCCD for detecting stenosis and occlusion of intracranial large arteries in people with acute ischaemic stroke. SEARCH METHODS:We limited our searches from January 1982 onwards as the transcranial Doppler technique was only introduced into clinical practice in the 1980s. We searched MEDLINE (Ovid) (from 1982 to 2018); Embase (Ovid) (from 1982 to 2018); Database of Abstracts of Reviews of Effects (DARE); and Health Technology Assessment Database (HTA) (from 1982 to 2018). Moreover, we perused the reference lists of all retrieved articles and of previously published relevant review articles, handsearched relevant conference proceedings, searched relevant websites, and contacted experts in the field. SELECTION CRITERIA:We included all studies comparing TCD or TCCD (index tests) with IA, CTA, MRA, or contrast-enhanced MRA (reference standards) in people with acute ischaemic stroke, where all participants underwent both the index test and the reference standard within 24 hours of symptom onset. We included prospective cohort studies and randomised studies of test comparisons. We also considered retrospective studies eligible for inclusion where the original population sample was recruited prospectively but the results were analysed retrospectively. DATA COLLECTION AND ANALYSIS:At least two review authors independently screened the titles and abstracts identified by the search strategies, applied the inclusion criteria, extracted data, assessed methodological quality (using QUADAS-2), and investigated heterogeneity. We contacted study authors for missing data. MAIN RESULTS:A comprehensive search of major relevant electronic databases (MEDLINE and Embase) from 1982 to 13 March 2018 yielded 13,534 articles, of which nine were deemed eligible for inclusion. The studies included a total of 493 participants. The mean age of included participants was 64.2 years (range 55.8 to 69.9 years). The proportion of men and women was similar across studies. Six studies recruited participants in Europe, one in south America, one in China, and one in Egypt. Risk of bias was high for participant selection but low for flow, timing, index and reference standard. The summary sensitivity and specificity estimates for TCD and TCCD were 95% (95% CI = 0.83 to 0.99) and 95% (95% CI = 0.90 to 0.98), respectively. Considering a prevalence of stenosis or occlusion of 42% (as reported in the literature), for every 1000 people who receive a TCD or TCCD test, stenosis or occlusion will be missed in 21 people (95% CI = 4 to 71) and 29 (95% CI = 12 to 58) will be wrongly diagnosed as harbouring an intracranial occlusion. However, there was substantial heterogeneity between studies, which was no longer evident when only occlusion of the MCA was considered, or when the analysis was limited to participants investigated within six hours. The performance of either TCD or TCCD in ruling in and ruling out a MCA occlusion was good. Limitations of this review were the small number of identified studies and the lack of data on the use of ultrasound contrast medium. AUTHORS' CONCLUSIONS:This review provides evidence that TCD or TCCD, administered by professionals with adequate experience and skills, can provide useful diagnostic information for detecting stenosis or occlusion of intracranial vessels in people with acute ischaemic stroke, or guide the request for more invasive vascular neuroimaging, especially where CT or MR-based vascular imaging are not immediately available. More studies are needed to confirm or refute the results of this review in a larger sample of stroke patients, to verify the role of contrast medium and to evaluate the clinical advantage of the use of ultrasound.
Use of Transcranial Doppler in Patients with Severe Traumatic Brain Injuries.
Ziegler Daniel,Cravens George,Poche Gerard,Gandhi Raj,Tellez Mark
Journal of neurotrauma
Severe traumatic brain injuries (TBI) are associated with a high rate of mortality and disability. Transcranial Doppler (TCD) sonography permits a noninvasive measurement of cerebral blood flow. The purpose of this study is to determine the usefulness of TCD in patients with severe TBI. TCD was performed, from April 2008 to April 2013, on 255 patients with severe TBI, defined as a Glasgow Coma Scale score of ≤8 on admission. TCD was performed on hospital days 1, 2, 3, and 7. Hypoperfusion was defined by having two out of three of the following: 1) mean velocity (Vm) of the middle cerebral artery <35 cm/sec, 2) diastolic velocity (Vd) of the middle cerebral artery <20 cm/sec, or 3) pulsatility index (PI) of >1.4. Vasospasm was defined by the following: Vm of the middle cerebral artery >120 cm/sec and/or a Lindegaard index (LI) >3. One hundred fourteen (45%) had normal measurements. Of these, 92 (80.7%) had a good outcome, 6 (5.3%) had moderate disability, and 16 (14%) died, 4 from brain death. Seventy-two patients (28%) had hypoperfusion and 71 (98.6%) died, 65 from brain death, and 1 patient survived with moderate disability. Sixty-nine patients (27%) had vasospasm, 31 (44.9%) had a good outcome, 16 (23.2%) had severe disability, and 22 (31.9%) died, 13 from brain death. The vasospasm was detected on hospital day 1 in 8 patients, on day 2 in 23 patients, on day 3 in 22 patients, and on day 7 in 16 patients. Patients with normal measurements can be expected to survive. Patients with hypoperfusion have a poor prognosis. Patients with vasospasm have a high incidence of mortality and severe disability. TCD is useful in determining early prognosis.
Non-invasive Monitoring of Intracranial Pressure Using Transcranial Doppler Ultrasonography: Is It Possible?
Cardim Danilo,Robba C,Bohdanowicz M,Donnelly J,Cabella B,Liu X,Cabeleira M,Smielewski P,Schmidt B,Czosnyka M
Although intracranial pressure (ICP) is essential to guide management of patients suffering from acute brain diseases, this signal is often neglected outside the neurocritical care environment. This is mainly attributed to the intrinsic risks of the available invasive techniques, which have prevented ICP monitoring in many conditions affecting the intracranial homeostasis, from mild traumatic brain injury to liver encephalopathy. In such scenario, methods for non-invasive monitoring of ICP (nICP) could improve clinical management of these conditions. A review of the literature was performed on PUBMED using the search keywords 'Transcranial Doppler non-invasive intracranial pressure.' Transcranial Doppler (TCD) is a technique primarily aimed at assessing the cerebrovascular dynamics through the cerebral blood flow velocity (FV). Its applicability for nICP assessment emerged from observation that some TCD-derived parameters change during increase of ICP, such as the shape of FV pulse waveform or pulsatility index. Methods were grouped as: based on TCD pulsatility index; aimed at non-invasive estimation of cerebral perfusion pressure and model-based methods. Published studies present with different accuracies, with prediction abilities (AUCs) for detection of ICP ≥20 mmHg ranging from 0.62 to 0.92. This discrepancy could result from inconsistent assessment measures and application in different conditions, from traumatic brain injury to hydrocephalus and stroke. Most of the reports stress a potential advantage of TCD as it provides the possibility to monitor changes of ICP in time. Overall accuracy for TCD-based methods ranges around ±12 mmHg, with a great potential of tracing dynamical changes of ICP in time, particularly those of vasogenic nature.
Relationship between flow diversion on transcranial Doppler sonography and leptomeningeal collateral circulation in patients with middle cerebral artery occlusive disorder.
Kim Yosik,Sin Dae-Soo,Park Hyun-Young,Park Man-Seok,Cho Ki-Hyun
Journal of neuroimaging : official journal of the American Society of Neuroimaging
BACKGROUND:Flow diversion (FD) has been considered as indirect evidence of intracranial artery occlusion, and it was associated with early improvement in patients with MCA occlusion. It is not known whether FD can represent leptomeningeal collateral circulation or not in patients with middle cerebral artery (MCA) occlusive disorder. PATIENTS AND METHODS:FD was defined by increased velocity (>30%) in anterior or posterior cerebral artery (ACA, PCA) compared to contralateral analogs artery in patients with MCA occlusive disorder. The leptomeningeal collateral channel (LMC) was identified using digital subtraction angiography. RESULTS:A total of 51 patients were enrolled in this analysis. Transcranial Doppler (TCD) showed a FD in 47% (24) of patients. Twenty-three patients had FD in ACA, and 1 patient in PCA. LMC was identified in 41% (21) of patients. Sensitivity of FD for leptomeningeal collateral circulation was 81%, specificity 76.7%, positive predictive value 70.8%, and negative predictive value 85.2%. Presence of FD showed good correlation with presence of LMCs in patients with MCA stenosis (r= .568, P= .00) CONCLUSION:FD on TCD suggests the presence of leptomeningeal collateral circulation in patients with MCA occlusive disorder.
Transcranial Doppler ultrasonography in neurological surgery and neurocritical care.
Bonow Robert H,Young Christopher C,Bass David I,Moore Anne,Levitt Michael R
Transcranial Doppler (TCD) ultrasonography is an inexpensive, noninvasive means of measuring blood flow within the arteries of the brain. In this review, the authors outline the technology underlying TCD ultrasonography and describe its uses in patients with neurosurgical diseases. One of the most common uses of TCD ultrasonography is monitoring for vasospasm following subarachnoid hemorrhage. In this setting, elevated blood flow velocities serve as a proxy for vasospasm and can herald the onset of ischemia. TCD ultrasonography is also useful in the evaluation and management of occlusive cerebrovascular disease. Monitoring for microembolic signals enables stratification of stroke risk due to carotid stenosis and can also be used to clarify stroke etiology. TCD ultrasonography can identify patients with exhausted cerebrovascular reserve, and after extracranial-intracranial bypass procedures it can be used to assess adequacy of flow through the graft. Finally, assessment of cerebral autoregulation can be performed using TCD ultrasonography, providing data important to the management of patients with severe traumatic brain injury. As the clinical applications of TCD ultrasonography have expanded over time, so has their importance in the management of neurosurgical patients. Familiarity with this diagnostic tool is crucial for the modern neurological surgeon.
Cerebral autoregulation in hemorrhagic stroke: A systematic review and meta-analysis of transcranial Doppler ultrasonography studies.
Minhas Jatinder S,Panerai Ronney B,Ghaly George,Divall Pip,Robinson Thompson G
Journal of clinical ultrasound : JCU
PURPOSE:International guidelines advocate intensive blood pressure (BP) lowering within 6 hours of acute intracerebral hemorrhage (ICH) to a target systolic BP of 130-140 mm Hg, though more intensive lowering may be associated with adverse outcome. Observational studies suggest impaired cerebral autoregulation (CA) following ICH. Transcranial Doppler ultrasonography (TCD), alongside continuous BP monitoring, provides a noninvasive bedside investigation that offers detailed perspectives on physiological perturbations post-acute ICH. This systematic review and meta-analysis focuses on all TCD studies of CA in ICH. METHODS:MEDLINE, EMBASE, and CENTRAL were searched for studies of hemorrhagic stroke and blood flow measurement. RESULTS:Eight studies met inclusion criteria (293 ICH patients); CA was impaired up to 12-days post-acute ICH. Impaired CA was evidenced by reduced transfer function analysis phase and higher mean flow correlation values: these were associated with worsened clinical parameters including ICH-volume and Glasgow Coma Scale. Meta-analysis of CBV demonstrated that, compared to controls, mean CBV was significantly lower in the ipsilateral (49.7 vs 64.8 cm s , Z = 4.26, P < .0001) and contralateral hemispheres following ICH (51.5 vs 64.8 cm s , Z = 3.44, P = .0006). CONCLUSION:Lower mean CBV in combination with impaired CA may have implications for more intensive BP lowering and warrants further studies examining such strategies on cerebral blood flow and its regulatory mechanisms.
Transcranial Duplex Sonography Predicts Outcome following an Intracerebral Hemorrhage.
Camps-Renom P,Méndez J,Granell E,Casoni F,Prats-Sánchez L,Martínez-Domeño A,Guisado-Alonso D,Martí-Fàbregas J,Delgado-Mederos R
AJNR. American journal of neuroradiology
BACKGROUND AND PURPOSE:Several radiologic features such as hematoma volume are related to poor outcome following an intracerebral hemorrhage and can be measured with transcranial duplex sonography. We sought to determine the prognostic value of transcranial duplex sonography in patients with intracerebral hemorrhage. MATERIALS AND METHODS:We conducted a prospective study of patients diagnosed with spontaneous intracerebral hemorrhage. Transcranial duplex sonography examinations were performed within 2 hours of baseline CT, and we recorded the following variables: hematoma volume, midline shift, third ventricle and lateral ventricle diameters, and the pulsatility index in both MCAs. We correlated these data with the CT scans and assessed the prognostic value of the transcranial duplex sonography measurements. We assessed early neurologic deterioration during hospitalization and mortality at 1-month follow-up. RESULTS:We included 35 patients with a mean age of 72.2 ± 12.8 years. Median baseline hematoma volume was 9.85 mL (interquartile range, 2.74-68.29 mL). We found good agreement and excellent correlation between transcranial duplex sonography and CT when measuring hematoma volume ( = 0.791; < .001) and midline shift ( = 0.827; < .001). The logistic regression analysis with transcranial duplex sonography measurements showed that hematoma volume was an independent predictor of early neurologic deterioration (OR, 1.078; 95% CI, 1.023-1.135) and mortality (OR, 1.089; 95% CI, 1.020-1.160). A second regression analysis with CT variables also demonstrated that hematoma volume was associated with early neurologic deterioration and mortality. When we compared the rating operation curves of both models, their predictive power was similar. CONCLUSIONS:Transcranial duplex sonography showed an excellent correlation with CT in assessing hematoma volume and midline shift in patients with intracerebral hemorrhage. Hematoma volume measured with transcranial duplex sonography was an independent predictor of poor outcome.
Cerebral blood flow and transcranial doppler sonography measurements of CO2-reactivity in acute traumatic brain injured patients.
Reinstrup Peter,Ryding Erik,Asgeirsson Bogi,Hesselgard Karin,Unden Johan,Romner Bertil
BACKGROUND:Cerebral blood flow (CBF) measurements are helpful in managing patients with traumatic brain injury (TBI), and testing the cerebrovascular reactivity to CO(2) provides information about injury severity and outcome. The complexity and potential hazard of performing CBF measurements limits routine clinical use. An alternative approach is to measure the CBF velocity using bedside, non-invasive, and transcranial Doppler (TCD) sonography. This study was performed to investigate if TCD is a useful alternative to CBF in patients with severe TBI. METHOD:CBF and TCD flow velocity measurements and cerebrovascular reactivity to hypocapnia were simultaneously evaluated in 27 patients with acute TBI. Measurements were performed preoperatively during controlled normocapnia and hypocapnia in patients scheduled for hematoma evacuation under general anesthesia. MAIN FINDING AND CONCLUSION:Although the lack of statistical correlation between the calculated reactivity indices, there was a significant decrease in TCD-mean flow velocity and a decrease in CBF with hypocapnia. CBF and TCD do not seem to be directly interchangeable in determining CO(2)-reactivity in TBI, despite both methods demonstrating deviation in the same direction during hypocapnia. TCD and CBF measurements both provide useful information on cerebrovascular events which, although not interchangeable, may complement each other in clinical scenarios.
Middle cerebral arterial flow changes on transcranial color and spectral Doppler sonography in patients with increased intracranial pressure.
Wang Yu,Duan Yun-You,Zhou Hai-Yan,Yuan Li-Jun,Zhang Li,Wang Wei,Li Li-Hong,Li Liang
Journal of ultrasound in medicine : official journal of the American Institute of Ultrasound in Medicine
OBJECTIVES:Intracranial pressure usually increases after severe brain injury. However, a method for noninvasive evaluation of intracranial pressure is still lacking. The purpose of this study was to explore the potential role of transcranial color Doppler sonography in assessing intracranial pressure by observing the middle cerebral artery blood flow parameters in patients with increased intracranial pressure of varying etiology. METHODS:The hemodynamic changes in the middle cerebral artery in patients with varying degrees of increased intracranial pressure were investigated by transcranial color Doppler sonography in 93 patients who had emergency surgery for brain injury. RESULTS:Middle cerebral artery Doppler flow spectra changed regularly as intracranial pressure increased. The pulsatility index (PI) and resistive index (RI) had a significantly positive correlation with intracranial pressure (r = 0.90 and 0.89, respectively; P< .001), whereas the middle cerebral artery diastolic velocity showed a significant negative correlation with intracranial pressure (r = -0.52; P< .01). A receiver operating characteristic curve showed that the RI and PI cutoff values were 0.705 and 1.335, respectively, for predicting increased intracranial pressure, with sensitivity of 0.885 and specificity of 0.970. CONCLUSIONS:In addition to the PI and RI, middle cerebral artery diastolic flow velocity measurement by transcranial color Doppler sonography may also be a useful variable for evaluating intracranial pressure in patients with acute brain injury.
Transcranial Doppler Sonography: Atypical Dicrotic Pulse Waveforms in a Man with HIV Infection and Severe Cardiomyopathy.
Suwatcharangkoon Sureerat,Meads Dana B,Tegeler Charles H,Reynolds Patrick S
Journal of neuroimaging : official journal of the American Society of Neuroimaging
A 27-year-old human immunodeficiency virus--positive man presented with abdominal pain. Computed tomography of the abdomen revealed large right pleural effusion, pericardial effusion and marked ascites with diffuse intra- and extraperitoneal lymphadenopathy. Echocardiography showed severely reduced left ventricular systolic function. After drainage of pleural and pericardial fluid, the patient developed severe hypotension and hypoxic respiratory failure. Extra- and intracranial neurovascular sonography demonstrated low carotid artery flow volume and dicrotic pulse waveforms in all vessels insonated bilaterally. This case report demonstrates an atypical dicrotic waveform pattern of transcranial Doppler in advanced ventricular dysfunction with shock.
Transcranial Doppler Monitoring in Carotid Endarterectomy: A Systematic Review and Meta-analysis.
Udesh Reshmi,Natarajan Piruthiviraj,Thiagarajan Karthy,Wechsler Lawrence R,Crammond Donald J,Balzer Jeffrey R,Thirumala Parthasarathy D
Journal of ultrasound in medicine : official journal of the American Institute of Ultrasound in Medicine
OBJECTIVES:To evaluate the efficacy of intraoperative transcranial Doppler monitoring in predicting perioperative strokes after carotid endarterectomy (CEA). METHODS:An electronic search of PubMed, Embase, and Web of Science databases was conducted for studies on transcranial Doppler monitoring in CEA published from January 1970 through September 2015. All titles and abstracts were independently screened on the basis of predetermined inclusion criteria, which included randomized clinical trials and prospective or retrospective cohort reviews, patients who underwent CEA with intraoperative transcranial Doppler monitoring (either middle cerebral artery velocity [MCAV] or cerebral microembolic signals [MES]) and postoperative neurologic assessments up to 30 days after the surgery, and studies including an abstract, published in English on adult humans 18 years and older with a sample size of 50 or greater. RESULTS:A total of 25articles with a sample population of 4705 patients were analyzed. Among the study patients, 189 developed perioperative strokes. Transcranial Doppler monitoring (either MCAV or MES) showed specificity of 72.7% (95% confidence interval [CI], 61.2%-81.8%) and sensitivity of 56.1% (95% CI, 46.8%-65.0%) for predicting perioperative strokes. Intraoperative MCAV changes during CEA showed strong specificity of 84.1% (95% CI, 74.4%-90.6) and sensitivity of 49.7% (95% CI, 40.6%-58.8) for predicting perioperative strokes. CONCLUSIONS:Patients with perioperative strokes are 4 times more likely to have had transcranial Doppler changes (either MCAV or MES) during CEA compared to patients without strokes. Simultaneous MCAV and MES monitoring by transcranial Doppler sonography and combined intraoperative monitoring of transcranial Doppler sonography with somatosensory evoked potentials and electroencephalography during CEA to predict perioperative stroke could not be evaluated because of a lack of clinical studies combining these measures.
Arterial blood gas analysis of samples directly obtained beyond cerebral arterial occlusion during endovascular procedures predicts clinical outcome.
Flores Alan,Sargento-Freitas Joao,Pagola Jorge,Rodriguez-Luna David,Piñeiro Socorro,Maisterra Olga,Rubiera Marta,Montaner Joan,Alvarez-Sabin Jose,Molina Carlos,Ribo Marc
Journal of neuroimaging : official journal of the American Society of Neuroimaging
UNLABELLED:Real-time intra-procedure information about ischemic brain damage degree may help physicians in taking decisions about pursuing or not recanalization efforts. METHODS:We studied gasometric parameters of blood samples drawn through microcatheter in 16 stroke patients who received endovascular reperfusion procedures. After crossing the clot with microcatheter, blood sample was obtained from the middle cerebral artery (MCA) segment distal to occlusion (PostOcc); another sample was obtained from carotid artery (PreOcc). An arterial blood gas (ABG) study was immediately performed. We defined clinical improvement as National Institutes of Health Stroke Scale (NIHSS) decrease of ≥4. RESULTS:The ABG analysis showed differences between PreOcc and PostOcc blood samples in mean oxygen partial pressure (Pre-PaO2: 78.9 ± 16 .3 vs. 73.9 ± 14 .9 mmHg; P < .001). Patients who presented clinical improvement had higher Post-PaO2 (81 ± 11 .4 vs. 64.8 ± 14 .4 mmHg; P = .025). A receiver-operator characteristic (ROC) curve determined Post-PaO2 > 70 mmHg that better predicted further clinical improvement. Patients with Post-PaO2 > 70 mmHg had higher chances of clinical improvement (81.8% vs. 0%; P = .002) and lower disability (median mRS:3 vs. 6; P= .024). In the logistic regression the only independent predictor of clinical improvement was Post-PaO2 > 70 (OR: 5.21 95% CI: 1.38-67.24; P = .013). CONCLUSION:Direct local blood sampling from ischemic brain is feasible during endovascular procedures in acute stroke patients. A gradient in oxygenation parameters was demonstrated between pre- and post-occlusion blood samples. ABG information may be used to predict clinical outcome and help in decision making in the angio-suite.
Blood Pressure Management for Acute Ischemic and Hemorrhagic Stroke: The Evidence.
Ko Sang-Bae,Yoon Byung-Woo
Seminars in respiratory and critical care medicine
Hypertension is the most common modifiable risk factor for stroke (both ischemic and hemorrhagic types). In the hyperacute phase, a majority of patients shows an elevated blood pressure (BP) at the time of presentation because of sympathetic hyperactivity or a physiological response to tissue ischemia. Therefore, BP may decrease spontaneously in a few hours and may drop further when complete recanalization is achieved. In stroke guidelines, an elevated BP is usually left untreated up to a systolic BP (SBP) of 220 mm Hg and a diastolic BP of 120 mm Hg. This recommendation is based on the BP level that corresponds to the upper limit of the pressure autoregulation zone above which cerebral blood flow is directly dependent on BP. However, in patients in whom administration of recombinant tissue-type plasminogen activator is indicated, BP should be controlled to a level < 185/110 mm Hg before infusion and should be maintained at levels < 180/105 mm Hg to limit the risk of intracerebral hemorrhage (ICH). In cases where endovascular thrombectomy is considered, the optimal intra- and postprocedural BP target have not yet been clearly identified. Expert opinion recommends that intraprocedural BP reduction could be associated with a risk of poor outcomes, and therefore, SBP may be reduced only to 120 to 140 mm Hg after successful reperfusion therapy. However, this recommendation is primarily based on observational studies and requires validation in prospective trials. It has been observed that in patients presenting with an ICH, there is no perihematomal penumbra noted and rapid BP reduction is generally well tolerated without a risk of neurological worsening. Multiple trials describing acute reduction of BP recommend SBP reduction only to 140 mm Hg because while there is no benefit of better functional outcomes below that level, there exists a definite risk of increased renal complications.
Management of Blood Pressure During and After Recanalization Therapy for Acute Ischemic Stroke.
Vitt Jeffrey R,Trillanes Michael,Hemphill J Claude
Frontiers in neurology
Ischemic stroke is a common neurologic condition and can lead to significant long term disability and death. Observational studies have demonstrated worse outcomes in patients presenting with the extremes of blood pressure as well as with hemodynamic variability. Despite these associations, optimal hemodynamic management in the immediate period of ischemic stroke remains an unresolved issue, particularly in the modern era of revascularization therapies. While guidelines exist for BP thresholds during and after thrombolytic therapy, there is substantially less data to guide management during mechanical thrombectomy. Ideal blood pressure targets after attempted recanalization depend both on the degree of reperfusion achieved as well as the extent of infarction present. Following complete reperfusion, lower blood pressure targets may be warranted to prevent reperfusion injury and promote penumbra recovery however prospective clinical trials addressing this issue are warranted.
Impact of blood pressure levels within first 24 hours after mechanical thrombectomy on clinical outcome in acute ischemic stroke patients.
Cernik David,Sanak Daniel,Divisova Petra,Kocher Martin,Cihlar Filip,Zapletalova Jana,Veverka Tomas,Prcuchova Andrea,Ospalik Dusan,Cerna Marie,Janousova Petra,Kral Michal,Dornak Tomas,Prasil Vojtech,Franc David,Kanovsky Petr
Journal of neurointerventional surgery
INTRODUCTION:Despite early management and technical success of mechanical thrombectomy (MT) for acute ischemic stroke (AIS), not all patients reach a good clinical outcome. Different factors may have an impact and we aimed to evaluate blood pressure (BP) levels in the first 24 hours after MT. METHODS:Consecutive AIS patients treated with MT were enrolled in the retrospective bi-center study. Neurological deficit was assessed with National Institutes of Health Stroke Scale (NIHSS) and functional outcome after 3 months with modified Rankin scale (mRS) with a score 0-2 for good outcome. The presence of symptomatic intracerebral hemorrhage (SICH) was assessed according to the SITS-MOST criteria. RESULTS:Of 703 treated patients, completed BP levels were collected in 690 patients (350 males, mean age 71±13 years) with median of admission NIHSS 17 points. Patients with mRS 0-2 had a lower median of systolic BP (SBP) compared with those with poor outcome (131 vs 140 mm Hg, P<0.0001). The rate of SICH did not differ between the patients with a median of SBP <140 mm Hg and ≥140 mm Hg. (5.1% vs 5.1%, P=0.980). Multivariate regression analysis with adjustment for potential confounders showed a median of distolic BP (P=0.024, OR: 0.977, 95% CI: 0.957 to 0.997) as a predictor of good functional outcome after MT, and a median of maximal SBP (P=0.038; OR: 0.990, 95% CI: 0.981 to 0.999) in the patients with achieved recanalization. CONCLUSION:Lowering of BP within the first 24 hours after MT may have a positive impact on clinical outcome in treated patients.
High Systolic Blood Pressure after Successful Endovascular Treatment Affects Early Functional Outcome in Acute Ischemic Stroke.
Maier Ilko L,Tsogkas Ioannis,Behme Daniel,Bähr Mathias,Knauth Michael,Psychogios Marios-Nikos,Liman Jan
Cerebrovascular diseases (Basel, Switzerland)
BACKGROUND:Endovascular treatment (EVT) has been shown to significantly improve functional outcome in patients with acute large cerebral vessel occlusions. To date, no evidence-based recommendations on blood pressure management after successful EVT exist. Previous studies showed an association between high pre-EVT systolic blood pressure (SBP) and functional outcome, but do not answer the question on how to manage blood pressure after successful recanalization. The purpose of this study was to determine the role of blood pressure measurements as a predictor for early functional outcome in patients with successful EVT. METHODS:Prospectively derived data from patients with acute large vessel occlusion within the anterior circulation and EVT was analyzed in this monocentric study. Mean systolic- and maximum SBP as well as SBP-peaks have been obtained for the first 24 h after successful EVT. Predictive value of SBP for discharge modified Rankin Scale (mRS) ≤2 has been investigated using logistic regression models. RESULTS:From 168 patients with successful EVT, 74 (44%) had a favorable outcome with an mRS ≤2. Mean- (127 vs. 131 mm Hg, p = 0.035) and maximum SBP (157 vs. 169 mm Hg, p < 0.001) as well as the number of SBP-peaks (0 vs. 1.5, p = 0.004) were lower in patients with favorable outcomes. Multivariable logistic regression showed high mean- and maximum SBP to predict unfavorable outcomes. Cutoff mean SBP was 141 mm Hg and maximum SBP 159 mm Hg. CONCLUSIONS:High SBP in the first 24 h after recanalization of acute anterior cerebral vessel occlusions is associated with unfavorable functional outcome. Interventional studies are needed to determine the role of SBP management as a modifiable parameter in the early phase after successful EVT.
Postreperfusion Blood Pressure Variability After Endovascular Thrombectomy Affects Outcomes in Acute Ischemic Stroke Patients With Poor Collateral Circulation.
Chang Jun Young,Jeon Sang-Beom,Jung Cheolkyu,Gwak Dong Seok,Han Moon-Ku
Frontiers in neurology
We evaluated the effect of 24 h blood pressure variability (BPV) on clinical outcomes in acute ischemic stroke patients with successful recanalization after endovascular recanalization therapy (ERT). Patients with anterior circulation occlusion were evaluated if they underwent ERT based on multiphase computed tomography angiography and achieved successful recanalization (≥thrombolysis in cerebral ischemia 2b). Collateral degrees were dichotomized based on the pial arterial filling score, with a score of 0-3 defined as a poor collateral status. BPV parameters include mean, standard deviation, coefficient of variation, and variation independent of the mean (VIM) for systolic blood pressure (SBP), diastolic blood pressure (DBP), mean blood pressure, and pulse rate (PR). These parameters were measured for 24 h after ERT and were analyzed according to occlusion sites and stroke mechanisms. Associations of BPV parameters with clinical outcomes were investigated with stratification based on the baseline collateral status. BPV was significantly different according to the occlusion sites and stroke mechanisms, and higher BPV was observed in patients with internal carotid artery occlusion or cardioembolic occlusion. After adjustment for confounders, most BPV parameters remained significant to predict functional outcomes at 3 months in patients with poor collateral circulation. However, no significant association was found between BPV parameters and clinical outcomes in patients with good collateral circulation. Postreperfusion BP management by decreasing BPV may have influence on improving clinical outcome in cases of poor collateral circulation among patients achieving successful recanalization after ERT.
Blood pressure control for acute severe ischemic and hemorrhagic stroke.
Current opinion in critical care
PURPOSE OF REVIEW:Severe ischemic or hemorrhagic stroke is a devastating cerebrovascular disease often demanding critical care. Optimal management of blood pressure (BP) in the acute phase is controversial. The purpose of this review is to display insights from recent studies on BP control in both conditions. RECENT FINDINGS:BP control in acute ischemic stroke has recently been investigated with regard to endovascular recanalizing therapies. Decreases from baseline BP and hypotension during the intervention have been found detrimental. Overall, a periinterventional SBP between 140 and 160 mmHg appeared favorable in several studies. In acute hemorrhagic stroke, the recently completed Antihypertensive Treatment of Acute Cerebral Hemorrhage II trial confirmed feasibility of early aggressive BP reduction but failed to demonstrate a reduction in hematoma growth or a clinical benefit. SUMMARY:Recent findings do not support benefits of intensive BP lowering in both acute hemorrhagic and ischemic stroke, with the possible exception of the postinterventional phase after successful endovascular recanalization of large-vessel occlusions. Although optimal ranges of BP values remain to be defined, high BP should still be treated according to guidelines. As stroke patients requiring critical care are underrepresented in most studies on BP, caution in transferring these findings is warranted and prospective research in that patient population needed.
The Relationship between Blood Pressure Variability, Recanalization Degree, and Clinical Outcome in Large Vessel Occlusive Stroke after an Intra-Arterial Thrombectomy.
Chang Jun Young,Jeon Sang Beom,Lee Jung Hwa,Kwon O-Ki,Han Moon-Ku
Cerebrovascular diseases (Basel, Switzerland)
BACKGROUND:Blood pressure variability (BPV) is associated with target organ damage progression and increased cardiovascular events, including stroke. The aim of this study was to evaluate the associations between short-term BPV during acute periods and recanalization degree, early neurological deterioration (END) occurrence, and functional outcomes in acute ischemic stroke patients who had undergone intra-arterial thrombectomy (IAT). METHODS:We retrospectively analyzed 303 patients with large vessel occlusive stroke who underwent IAT. The following BPV parameters, measured over 24 and 48 h after IAT, were compared: the mean, SD, coefficient of variation (CV), variation independent of the mean (VIM) for both the systolic BP (SBP) and diastolic BP, and the proportion of nocturnal SBP risers. RESULTS:BPV parameters decreased with higher recanalization degree. The mean SBP (SBPmean) over 24 and 48 h after IAT, and the SD of SBP (SBPSD), CV of SBP (SBPCV), and VIM of SBP (SBPVIM) during the 48 h following the procedure had significant associations with recanalization degree. Patients with END had higher BPV than that of those without END, and the difference was more evident for incomplete recanalization. Increased BPV was associated with a shift toward poor functional outcome at 3 months after adjustment, including recanalization degree (OR range for significant parameters, 1.26-1.64, p = 0.006 for 48 h SBPmean, p = 0.003 for 48 h SBPCV, otherwise p < 0.002). CONCLUSIONS:Short-term BPV over 24 and 48 h after IAT in acute ischemic stroke patients was related to recanalization degree, and END occurrence, and may be an independent predictor of clinical outcome.
Recanalization Modulates Association Between Blood Pressure and Functional Outcome in Acute Ischemic Stroke.
Martins Ana Inês,Sargento-Freitas João,Silva Fernando,Jesus-Ribeiro Joana,Correia Inês,Gomes João Pedro,Aguiar-Gonçalves Mariana,Cardoso Leila,Machado Cristina,Rodrigues Bruno,Santo Gustavo C,Cunha Luís
BACKGROUND AND PURPOSE:Historical stroke cohorts reported a U- or J-shaped relationship between blood pressure (BP) and clinical outcome. However, these studies predated current revascularization strategies, disregarding the recanalization state of the affected arterial territory. We aimed to investigate the relationship between BP in the first 24 hours after ischemic stroke and clinical outcome in patients submitted to intravenous or intra-arterial recanalization treatments. METHODS:Consecutive patients with acute stroke treated with intravenous thrombolysis or intra-arterial therapies were enrolled in a retrospective cohort study. BP was measured on regular intervals throughout day and night during the first 24 hours after stroke onset. The mean systolic BP and diastolic BP during the first 24 hours post stroke were calculated. Recanalization was assessed at 6 hours by transcranial color-coded Doppler, angiography, or angio-computed tomography. Functional outcome was assessed at 3 months by modified Rankin Scale. Linear and quadratic multivariate regression models were performed to determine associations between BP and functional outcome for the whole population and recanalyzed and nonrecanalyzed patients. RESULTS:We included 674 patients; mean age was 73.28 (SD, 11.50) years. Arterial recanalization was documented in 355 (52.70%) patients. In multivariate analyses, systolic BP and diastolic BP in the first 24 hours post stroke show a J-shaped relationship with functional outcome in the total population and in the nonrecanalyzed patients. Recanalyzed patients show a linear association with functional outcome (systolic BP: odds ratio, 1.015; 95% confidence interval, 1.007-1.024; P=0.001; R(2) change=0.001; P=0.412 and diastolic BP: odds ratio, 1.019; 95% confidence interval, 1.004-1.033; P=0.012; R(2) change<0.001; P=0.635). CONCLUSIONS:Systemic BP in the first 24 hours after ischemic stroke influences 3-month clinical outcome. This association is dependent on the revascularization status.
Systolic Blood Pressure Within 24 Hours After Thrombectomy for Acute Ischemic Stroke Correlates With Outcome.
Mistry Eva A,Mistry Akshitkumar M,Nakawah Mohammad Obadah,Khattar Nicolas K,Fortuny Enzo M,Cruz Aurora S,Froehler Michael T,Chitale Rohan V,James Robert F,Fusco Matthew R,Volpi John J
Journal of the American Heart Association
BACKGROUND:Current guidelines suggest treating blood pressure above 180/105 mm Hg during the first 24 hours in patients with acute ischemic stroke undergoing any form of recanalization therapy. Currently, no studies exist to guide blood pressure management in patients with stroke treated specifically with mechanical thrombectomy. We aimed to determine the association between blood pressure parameters within the first 24 hours after mechanical thrombectomy and patient outcomes. METHODS AND RESULTS:We retrospectively studied a consecutive sample of adult patients who underwent mechanical thrombectomy for acute ischemic stroke of the anterior cerebral circulation at 3 institutions from March 2015 to October 2016. We collected the values of maximum, minimum, and average values of systolic blood pressure, diastolic blood pressure, and mean arterial pressures in the first 24 hours after mechanical thrombectomy. Primary and secondary outcomes were patients' functional status at 90 days measured on the modified Rankin scale and the incidence and severity of intracranial hemorrhages within 48 hours. Associations were explored using an ordered multivariable logistic regression analyses. A total of 228 patients were included (mean age 65.8±14.3; 104 males, 45.6%). Maximum systolic blood pressure independently correlated with a worse 90-day modified Rankin scale and hemorrhagic complications within 48 hours (adjusted odds ratio=1.02 [1.01-1.03], =0.004; 1.02 [1.01-1.04], =0.002; respectively) in multivariable analyses, after adjusting for several possible confounders. CONCLUSIONS:Higher peak values of systolic blood pressure independently correlated with worse 90-day modified Rankin scale and a higher rate of hemorrhagic complications. Further prospective studies are warranted to identify whether systolic blood pressure is a therapeutic target to improve outcomes.
Exploring Reperfusion Following Endovascular Thrombectomy.
Kosior Jayme C,Buck Brian,Wannamaker Robert,Kate Mahesh,Liapounova Natalia A,Rempel Jeremy L,Butcher Kenneth
Background and Purpose- Cerebral perfusion in acute ischemic stroke patients is often assessed before endovascular thrombectomy (EVT), but rarely after. Perfusion data obtained following EVT may provide additional prognostic information. We developed a tool to quantitatively derive perfusion measurements from digital subtraction angiography (DSA) data and examined perfusion in patients following EVT. Methods- Source DSA images from acute anterior circulation stroke patients undergoing EVT were retrospectively assessed. Following deconvolution, maps of mean transit time (MTT) were generated from post-EVT DSA source data. Thrombolysis in Cerebral Infarction grades and MTT in patients with and without hemorrhagic transformation (HT) at 24 hours were compared. Receiver operating characteristic modeling was used to classify the presence/absence of HT at 24 hours by MTT. Results- Perfusion maps were generated in 50 patients using DSA acquisitions that were a median (interquartile range) of 9 (8-10) seconds in duration. The median post-EVT MTT within the affected territory was 2.6 (2.2-3.3) seconds. HT was observed on follow-up computed tomography in 16 (32%) patients. Thrombolysis in Cerebral Infarction grades did not differ in patients with HT from those without (P=0.575). Post-EVT MTT maps demonstrated focal areas of hyperperfusion (n=8) or persisting hypoperfusion (n=3) corresponding to the regions where HT later developed. The relationship between MTT and HT was U-shaped; HT occurred in patients at both the lowest and highest extremes of MTT. An MTT threshold <2 or >4 seconds was 81% sensitive and 94% specific for classifying the presence of HT at follow-up. Conclusions- Perfusion measurements can be obtained using DSA perfusion with minimal changes to current stroke protocols. Perfusion imaging post-recanalization may have additional clinical utility beyond visual assessment of source angiographic images alone.
Cerebral hyperperfusion on arterial spin labeling MRI after reperfusion therapy is related to hemorrhagic transformation.
Okazaki Shuhei,Yamagami Hiroshi,Yoshimoto Takeshi,Morita Yoshiaki,Yamamoto Haruko,Toyoda Kazunori,Ihara Masafumi
Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism
Early detection of hemorrhagic transformation after reperfusion therapy is crucial in acute stroke treatment. Here, we evaluated the relationship between hemorrhagic transformation and post-reperfusion hyperperfusion using pulsed arterial spin labeling (ASL) perfusion MRI and I-iodoamphetamine single-photon emission-computed tomography. Patients who developed hemorrhagic transformation showed significantly higher cerebral blood flow in the affected lesion after thrombolysis and/or endovascular intervention. Focal hyperperfusion (ipsilateral to contralateral ratio >1.5) was associated with hemorrhagic transformation after reperfusion (odds ratio, 9.3; 95% confidence interval, 1.4-64.0). Our findings suggest that post-reperfusion hyperperfusion on ASL could represent a reliable marker of hemorrhagic transformation.
Cerebral Hyperperfusion Syndrome After Endovascular Reperfusion Therapy in a Patient with Acute Internal Carotid Artery and Middle Cerebral Artery Occlusions.
Hashimoto Tetsuya,Matsumoto Shoji,Ando Mitsushige,Chihara Hideo,Tsujimoto Atsushi,Hatano Taketo
BACKGROUND:Cerebral hyperperfusion syndrome (CHS) is known to be a rare but devastating complication of carotid artery revascularization. Because patients with acute ischemic stroke due to acute major cerebral and/or cervical artery occlusion treated with endovascular reperfusion therapy may have impaired autoregulation in the cerebral vasculature, these patients may also develop CHS. Despite the growing number of endovascular reperfusion procedures for acute ischemic stroke, this complication has only rarely been reported. CASE DESCRIPTION:A 77-year-old man developed acute cerebral infarction as the result of occlusions of the right internal carotid artery and right middle cerebral artery. After systemic intravenous injection of recombinant tissue-type plasminogen activator, endovascular reperfusion therapy was initiated. The occluded arteries were successfully recanalized with thrombectomy by using a stent retriever for the middle cerebral artery and stent placement for the origin of the internal carotid artery. However, head computed tomography obtained 12 hours after treatment showed acute intracranial hemorrhage that did not involve the ischemic lesions. Under evaluation with transcranial near-infrared spectroscopy and single-photon emission computed tomography, the hemorrhage was considered to have been caused by CHS after reperfusion therapy. CONCLUSIONS:CHS may lead to unfavorable outcomes after reperfusion therapy for acute ischemic stroke. Recognizing clinical deterioration caused by CHS can be challenging in patients with neurologic disorders of acute ischemic stroke. Therefore, it is important to perform routine monitoring of regional cerebral oxygen saturation by using near-infrared spectroscopy, perform single-photon emission computed tomography promptly to evaluate cerebral blood flow, and maintain strict antihypertensive therapy to prevent CHS after reperfusion therapy.
Hyperperfusion after Endovascular Reperfusion Therapy for Acute Ischemic Stroke.
Shimonaga Koji,Matsushige Toshinori,Hosogai Masahiro,Hashimoto Yukishige,Mizoue Tatsuya,Ono Chiaki,Kurisu Kaoru,Sakamoto Shigeyuki
Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association
BACKGROUND AND PURPOSE:Patients with acute ischemic stroke (AIS) may display prolonged neurological deficits and conscious disturbance even after successful endovascular thrombectomy. We hypothesized that hemodynamic change after reperfusion might influence outcomes. This study investigated the factors causing hyperperfusion and outcomes. METHODS:We retrospectively analyzed 27 patients with AIS who underwent successful acute revascularization (TICI: Thrombolysis in Cerebral Infarction 2b + 3). Changes of the neurological status were precisely assessed by using the National Institutes of Health Stroke Scale (NIHSS). Ischemic lesions were scored by MRI with diffusion-weighted imaging (DWI), and blood flow in the middle cerebral artery territory was assessed by MRI with arterial spin labeling. Univariate analysis was performed to investigate correlations between hyperperfusion and demographic factors or the functional prognosis. RESULTS:Thirteen of the 27 (48%) patients developed hyperperfusion after reperfusion. A significant correlation was seen between hyperperfusion and the improvement of NIHSS at 24 hours (P < .0001), the duration of disturbance of consciousness (days) (P < .0001), DWI-ASPECTS (P = .001), hemorrhagic transformation (P = .007), and mRS less than or equal to 2 at 90 days (P = .007). CONCLUSIONS:The present findings suggested that some patients with AIS will develop hyperperfusion after successful acute revascularization. The status of hyperperfusion could prolong conscious disturbance and affect outcomes. Since the mechanism of hyperperfusion after revascularization depends on stroke etiology, diagnosing the type of ischemic stroke in the acute stage is important for managing postoperative treatment.
Increased middle cerebral artery mean blood flow velocity index after stroke thrombectomy indicates increased risk for intracranial hemorrhage.
Kneihsl Markus,Niederkorn Kurt,Deutschmann Hannes,Enzinger Christian,Poltrum Birgit,Fischer Renate,Thaler Daniela,Hermetter Christina,Wünsch Gerit,Fazekas Franz,Gattringer Thomas
Journal of neurointerventional surgery
BACKGROUND AND PURPOSE:Cerebral hyperperfusion has been related to the risk of intracranial hemorrhage (ICH) in stroke patients after vessel recanalization therapy. We hypothesized that after successful mechanical thrombectomy for acute anterior circulation stroke, hemodynamics detectable by transcranial Duplex (TCD) sonography would vary, and that increased blood flow velocities would be associated with ICH. METHODS:We retrospectively identified all ischemic stroke patients with successful endovascular recanalization for anterior circulation vessel occlusion (Thrombolysis in Cerebral Infarction 2b-3) between 2010 and 2017. We reviewed their postinterventional TCD examinations for mean blood flow (MBF) velocities of the recanalized and contralateral middle cerebral artery (MCA) and searched for an association with postinterventional ICH and clinical outcome. RESULTS:123 stroke patients (mean age 63±14 years, 40% women) with successful anterior circulation thrombectomy were analyzed. Of those, 18 patients had postinterventional ICH. ICH patients had an increased MCA MBF velocity index (=MBF velocity of the recanalized divided by the contralateral MCA) compared with non-ICH patients (1.32±0.39 vs 1.02±0.32, P<0.001). In multivariate analysis, a higher MCA MBF velocity index was associated with postinterventional ICH and poor 90 day outcome. CONCLUSIONS:A high MCA MBF velocity index on TCD after successful recanalization therapy for anterior circulation stroke indicates a risk for postinterventional ICH and worse prognosis.