Rapid Eye Movement Sleep Behavior Disorder: A Review of the Literature and Update on Current Concepts. Rodriguez Carlos L,Jaimchariyatam Nattapong,Budur Kumar Chest Rapid eye movement (REM) sleep behavior disorder (RBD) is characterized by abnormal behaviors emerging during REM sleep that may cause injury or sleep disruption. The diagnosis requires polysomnography (PSG) demonstrating a loss of normal skeletal muscle atonia during REM sleep. RBD results from dysfunction of the brain stem circuits responsible for maintaining normal REM sleep atonia and suppressing behaviors during REM sleep. The diagnosis of idiopathic RBD (IRBD), that is, RBD without an identifiable cause, is frequently followed years later by the development of a neurodegenerative disorder, most commonly one of the synucleinopathies. As such, RBD is often a step in the progression of a neurodegenerative disorder. In this circumstance, it is a manifestation of neurodegeneration occurring in the brain stem before spreading to adjacent and other CNS regions, resulting in the development of symptoms and signs that permit recognition of a specific neurodegenerative disorder. RBD has been linked with narcolepsy and has been associated with a variety of other disorders. The management of RBD focuses on preventive/safety measures, counseling, monitoring for the development of a neurodegenerative disorder, and pharmacotherapy, which is typically effective but not well understood. The purpose of this article is to review and update our current understanding of the clinical features, epidemiology, demographics, pathophysiology, evaluation, diagnosis, differential diagnosis, causes, associations, and the clinical management of RBD. 10.1016/j.chest.2017.03.015
    Brain imaging findings in idiopathic REM sleep behavior disorder (RBD) - A systematic review on potential biomarkers for neurodegeneration. Heller Julia,Brcina Nikolina,Dogan Imis,Holtbernd Florian,Romanzetti Sandro,Schulz Jörg B,Schiefer Johannes,Reetz Kathrin Sleep medicine reviews Idiopathic rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia characterized by the loss of physiological atonia of skeletal muscles with abnormal behavior during dream sleep. RBD may be the initial manifestation of neurodegenerative diseases, particularly of α-synucleinopathies such as Parkinson's disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA). However, gauging the individual risk of subsequent phenoconversion and making assumptions on the type of disease that may subsequently follow RBD is challenging. Over the past years, a growing number of studies have sought to establish reliable neuroimaging markers to detect neurodegenerative brain changes in RBD subjects at the earliest possible stage. The present review summarizes recent advances in brain imaging in RBD and provides recommendations for the application of currently available structural and functional neuroimaging modalities to monitor disease progression and risk of subsequent phenoconversion. Further imaging research applying multimodal approaches is encouraged to enhance accuracy of prognoses. Additionally, more longitudinal studies are warranted to validate findings from cross-sectional studies on RBD progression and risk of subsequent phenoconversion. Aside from enabling reliable prognoses on a single-subject-level in the near future, this might give further insight into RBD pathophysiology, and finally augment the development of intervention strategies and disease-modifying therapies. 10.1016/j.smrv.2016.06.006
    Molecular Mechanisms of REM Sleep. Yamada Rikuhiro G,Ueda Hiroki R Frontiers in neuroscience Rapid-eye movement (REM) sleep is a paradoxical sleep state characterized by brain activity similar to wakefulness, rapid-eye-movement, and lack of muscle tone. REM sleep is a fundamental brain function, evolutionary conserved across species, including human, mouse, bird, and even reptiles. The physiological importance of REM sleep is highlighted by severe sleep disorders incurred by a failure in REM sleep regulation. Despite the intense interest in the mechanism of REM sleep regulation, the molecular machinery is largely left to be investigated. In models of REM sleep regulation, acetylcholine has been a pivotal component. However, even newly emerged techniques such as pharmacogenetics and optogenetics have not fully clarified the function of acetylcholine either at the cellular level or neural-circuit level. Recently, we discovered that the G type muscarinic acetylcholine receptor genes, and , are essential for REM sleep. In this review, we develop the perspective of current knowledge on REM sleep from a molecular viewpoint. This should be a starting point to clarify the molecular and cellular machinery underlying REM sleep regulation and will provide insights to explore physiological functions of REM sleep and its pathological roles in REM-sleep-related disorders such as depression, PTSD, and neurodegenerative diseases. 10.3389/fnins.2019.01402
    The Biology of REM Sleep. Peever John,Fuller Patrick M Current biology : CB Considerable advances in our understanding of the mechanisms and functions of rapid-eye-movement (REM) sleep have occurred over the past decade. Much of this progress can be attributed to the development of new neuroscience tools that have enabled high-precision interrogation of brain circuitry linked with REM sleep control, in turn revealing how REM sleep mechanisms themselves impact processes such as sensorimotor function. This review is intended to update the general scientific community about the recent mechanistic, functional and conceptual developments in our current understanding of REM sleep biology and pathobiology. Specifically, this review outlines the historical origins of the discovery of REM sleep, the diversity of REM sleep expression across and within species, the potential functions of REM sleep (e.g., memory consolidation), the neural circuits that control REM sleep, and how dysfunction of REM sleep mechanisms underlie debilitating sleep disorders such as REM sleep behaviour disorder and narcolepsy. 10.1016/j.cub.2017.10.026
    Association between excessive daytime sleepiness, REM phenotype and severity of obstructive sleep apnea. Gabryelska Agata,Białasiewicz Piotr Scientific reports The aim of the study was to compare REM-dependent and REM-independent, obstructive sleep apnea syndrome (OSA) patients in relation to their daily sleepiness assessed by Epworth sleepiness scale (ESS). The study included 1863 consecutive patients, who were referred to a sleep centre with a presumed diagnosis of OSA. Following polysomnography, 292 patients fulfilled criteria for either REM-dependent OSA (REM-OSA, n = 102) or REM-independent OSA (nREM-OSA, n = 190). Both study groups were matched regarding sex and age. REM-OSA group had two times lower median apnoea-hypopnea index (AHI) compared to nREM-OSA (p < 0.001), yet day-time sleepiness measured by ESS was similar: median score 9.0 (6.0-11.0) and 8.0 (4.8-11.0), p = 0.109, respectively. Subsequent post-hoc ANCOVA analysis, with covariates (BMI, percent of total sleep time spent in REM stage, percent of total sleep time spent in the supine position), has shown statistically significant difference between study groups regarding AHI (p < 0.001) and no difference regarding ESS score (p = 0.063). Despite two times lower AHI, patients with REM-OSA present with similar day-time sleepiness as those with REM independent OSA. Daily sleepiness may be stronger associated with apneas/hypopneas occurring in REM than nREM sleep. 10.1038/s41598-019-56478-9
    Circuit mechanisms and computational models of REM sleep. Héricé Charlotte,Patel Amisha A,Sakata Shuzo Neuroscience research Rapid eye movement (REM) sleep or paradoxical sleep is an elusive behavioral state. Since its discovery in the 1950s, our knowledge of the neuroanatomy, neurotransmitters and neuropeptides underlying REM sleep regulation has continually evolved in parallel with the development of novel technologies. Although the pons was initially discovered to be responsible for REM sleep, it has since been revealed that many components in the hypothalamus, midbrain, pons, and medulla also contribute to REM sleep. In this review, we first provide an up-to-date overview of REM sleep-regulating circuits in the brainstem and hypothalamus by summarizing experimental evidence from neuroanatomical, neurophysiological and gain- and loss-of-function studies. Second, because quantitative approaches are essential for understanding the complexity of REM sleep-regulating circuits and because mathematical models have provided valuable insights into the dynamics underlying REM sleep genesis and maintenance, we summarize computational studies of the sleep-wake cycle, with an emphasis on REM sleep regulation. Finally, we discuss outstanding issues for future studies. 10.1016/j.neures.2018.08.003
    Analysis of the myoelectric characteristics of genioglossus in REM sleep and its improvement by CPAP treatment in OSA patients. Zhou Yingqian,Zhao Di,Yin Guoping,Li Jingjing,Cao Xin,Zhang Yuhuan,Ye Jingying Sleep & breathing = Schlaf & Atmung OBJECTIVES:To reveal the characteristics of genioglossus (GG) activation in moderate and severe obstructive sleep apnea (OSA) patients during rapid eye movement (REM) sleep compared with non-rapid eye movement (NREM) sleep and to determine whether continuous positive airway pressure (CPAP) could improve GG activation in OSA patients during sleep. METHODS:All subjects underwent polysomnography (PSG) with synchronous GG electromyography (GGEMG) recording with intra-oral surface electrodes at baseline on the first night. Only those subjects diagnosed with moderate and severe OSA were included and were manually titrated with CPAP to achieve a therapeutic pressure (Pt) with GGEMG recording on the second night. RESULTS:Nine OSA patients and six normal controls were analyzed in this study. The tonic GGEMG was higher in OSA patients during wakefulness (p = 0.003) and NREM sleep (p = 0.015), but it was not higher in REM sleep (p = 0.862). The average phasic activity of OSA patients was significantly higher in all stages, including wakefulness (p = 0.007), NREM sleep (p = 0.005), and REM sleep (p = 0.021). The peak phasic GGEMG was not different in wakefulness compared with normal controls (p = 0.240), but it was higher in OSA patients in NREM sleep (p = 0.001) and REM sleep (p = 0.021), and it was significantly reduced by using CPAP during sleep (NREM sleep: p = 0.027; REM sleep: p = 0.001). CONCLUSIONS:Our results demonstrate that GG activation during NREM and REM sleep is associated with component differences. The tonic component of GGEMG exhibited less of a compensatory increase compared with the phasic component in REM sleep, suggesting that it may be one of the pathological mechanisms of UA collapsibility in REM sleep. In addition, treatment with CPAP can normalize GGEMG activity and mostly reduced the peak phasic GGEMG during sleep. 10.1007/s11325-019-01875-7
    Brain cholinergic alterations in idiopathic REM sleep behaviour disorder: a PET imaging study with F-FEOBV. Bedard Marc-Andre,Aghourian Meghmik,Legault-Denis Camille,Postuma Ronald B,Soucy Jean-Paul,Gagnon Jean-François,Pelletier Amélie,Montplaisir Jacques Sleep medicine BACKGROUND:REM sleep behaviour disorder (RBD) occurs frequently in patients with synucleinopathies such as Parkinson's disease, dementia with Lewy body, or multiple system atrophy, but may also occur as a prodromal stage of those diseases; and is termed idiopathic RBD (iRBD) when not accompanied by other symptoms. Cholinergic degeneration of the mesopontine nuclei have been described in synucleinopathies with or without RBD, but this has not yet been explored in iRBD. We sought to assess cholinergic neuronal integrity in iRBD using PET neuroimaging with the F-fluoroethoxybenzovesamicol (FEOBV). METHODS:The sample included 10 participants evenly divided between healthy subjects and patients with iRBD. Polysomnography and PET imaging with FEOBV were performed in all participants. Standardized uptake value ratios (SUVRs) were compared between the two groups using voxel wise t-tests. Non-parametric correlations were also computed in patients with iRBD between FEOBV uptake and muscle tonic and phasic activity during REM sleep. RESULTS:Compared with healthy participants, significantly higher FEOBV uptakes were observed in patients with iRBD. The largest differences were observed in specific brainstem areas corresponding to the bulbar reticular formation, pontine coeruleus/subcoeruleus complex, tegmental periacqueductal grey, and mesopontine cholinergic nuclei. FEOBV uptake in iRBD was also higher than in controls in the ventromedial area of the thalamus, deep cerebellar nuclei, and some cortical territories (including the paracentral lobule, anterior cingulate, and orbitofrontal cortex). Significant correlation was found between muscle activity during REM sleep, and SUVR increases in both the mesopontine area and paracentral cortex. CONCLUSION:We showed here for the first time the brain cholinergic alterations in patients with iRBD. As opposed to the cholinergic depletion described previously in RBD associated with clinical Parkinson's disease, increased cholinergic innervation was found in multiple areas in iRBD. The most significant changes were observed in brainstem areas containing structures involved in the promotion of REM sleep and muscle atonia. This suggests that iRBD might be a clinical condition in which compensatory cholinergic upregulation in those areas occurs in association with the initial phases of a neurodegenerative process leading to a clinically observable synucleinopathy. 10.1016/j.sleep.2018.12.020
    The association between REM sleep and decision-making: Supporting evidences. Brunet Jean-François,McNeil Jessica,Doucet Éric,Forest Geneviève Physiology & behavior Studies suggest that REM sleep is important for the maintenance of prefrontal cortex functioning. Therefore, reducing REM sleep may have an impact on cognitive functions such as impulse control and decision-making processes. This study examined the association between impulsiveness and sensation seeking personality traits, REM sleep and performance on a decision-making computer task following a habitual night of sleep and a partial sleep deprivation (PSD) condition with advanced wake-up time. Eighteen young adults participated in two experimental conditions: a control (habitual bedtime and wake time) and a 50% PSD with an advanced wake time. Impulsiveness and sensation seeking personality traits were measured with a personality inventory (NEO-PI-3), sleep was assessed using standard polysomnography and the Iowa Gambling Task (IGT) was completed at noon following each sleep condition. Results showed that when sleep deprived, participants choose more often to play riskier decks of cards during the last half of the IGT. Results also showed that REM sleep duration and REM sleep deprivation were associated with riskier decisions on the IGT. Moreover, impulsiveness was associated with riskier decisions after a normal night of sleep. These findings suggest that REM sleep duration and impulsiveness are important factors to consider while investigating decision-making processes under conditions of uncertainty and risk. 10.1016/j.physbeh.2020.113109
    Association Between Serum Lipid Profile and Obstructive Respiratory Events During REM and Non-REM Sleep. Bikov Andras,Lazar Zsofia,Horvath Peter,Tarnoki David Laszlo,Tarnoki Adam Domonkos,Fesus Luca,Horvath Marton,Meszaros Martina,Losonczy Gyorgy,Kunos Laszlo Lung PURPOSE:Obstructive sleep apnoea (OSA) represents a risk for dyslipidaemia. Obstructive respiratory events during rapid eye movement (REM) sleep are more strongly related to the development of hypertension and diabetes than in non-REM. However, the relationship between sleep phases and serum lipid profile is unclear. We aimed to analyse the relationship between obstructive respiratory events in REM and non-REM sleep as well as serum lipid profile. METHODS:Polysomnography was performed in 94 adult subjects who did not take any lipid-modifying medications. Fasting venous blood sample was taken the following morning for total cholesterol, triglyceride, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol, lipoprotein(a), apoprotein A1 (ApoA1) and for apoprotein B (ApoB) measurements. Lipid profiles were correlated with apnoea-hypopnoea index (AHI) during REM (AHI) and non-REM (AHI) stages in all subjects. In addition, lipid profiles were compared between REM-dependent OSA patients (AHI ≥ 5/h, but AHI < 5/h) and control subjects (both AHI and AHI < 5/h). RESULTS:AHI correlated only with triglyceride concentrations (p = 0.04, Spearman's rho, ρ = 0.21). In contrast, there was a significant association between AHI and triglyceride (p = 0.02, ρ = 0.23), ApoB (p = 0.03, ρ = 0.21), HDL-C (p < 0.01, ρ = - 0.32) as well as ApoA1 levels (p = 0.04, ρ = - 0.21). However, these correlations were not present after adjustment for BMI (all p > 0.05). There was no difference in the lipid profile of REM-dependent OSA subjects and healthy controls (p > 0.05). CONCLUSIONS:Altered serum lipid profile is equally associated with a disturbed REM and non-REM sleep in OSA. Obesity must be considered as a strong covariate when interpreting lipid data in sleep apnoea. 10.1007/s00408-019-00195-7
    REM Sleep without atonia correlates with abnormal vestibular-evoked myogenic potentials in isolated REM sleep behavior disorder. Puligheddu Monica,Figorilli Michela,Serra Alessandra,Laccu Ilaria,Congiu Patrizia,Tamburrino Ludovica,de Natale Edoardo Rosario,Ginatempo Francesca,Deriu Franca,Loi Gianluigi,Fantini Maria Livia,Schenck Carlos H,Ferri Raffaele Sleep STUDY OBJECTIVES:The neurophysiological hallmark of REM sleep behavior disorder (RBD) is loss of atonia during REM sleep. Indeed, signs and symptoms of neurodegeneration can occur after years, even decades, from its beginning. This study aimed to measure neurophysiological alterations of the brainstem that potentially correlate with the severity of atonia loss, and determining whether a prodromal neurodegenerative disorder underlines this condition when it occurs as an isolated condition (iRBD). METHODS:Subjects with iRBD and matched healthy controls were recruited. The study included the recording of one-night polysomnography, vestibular-evoked myogenic potentials (VEMPs), and a [123I]-FP-CIT dopamine transporter (DAT) scan. The quantification of REM sleep without atonia (RSWA) was made according to two previously published manual methods and one automated method. RESULTS:The rate of alteration of VEMPs and VEMP score were significantly higher in iRBD patients than controls. Moreover, VEMP score was negatively correlated with the automated REM atonia index; a marginal statistical significance was also reached for the positive correlation with the visual tonic electromyographic parameter, while the other correlations, including that with DAT-scan score were not statistically significant. CONCLUSIONS:Brainstem neurophysiology in iRBD can be assessed by VEMPs and their alterations may possibly indicate an early expression of the neurodegenerative process underlying this disorder at the brainstem level, which awaits future longitudinal confirmation. The correlation between RSWA and VEMP alteration might also represent a prodromal aspect anticipating the possible evolution from iRBD to neurodegeneration, whereas DAT-scan abnormalities might represent a later step in this evolution. 10.1093/sleep/zsz128
    The relationship between anxiety, depression, daytime sleepiness in the REM-related mild OSAS and the NREM-related mild OSAS. Geckil Aysegul Altintop,Ermis Hilal Sleep & breathing = Schlaf & Atmung INTRODUCTION:Obstructive sleep apnea syndrome (OSAS) is a common form of sleep-related respiratory disease characterized by recurrent blockages in the upper airway. Rapid eye movement (REM)-related OSAS is a condition in which apneas and hypopneas are more common during REM sleep. We investigated whether there was any difference between REM-related mild OSAS group and NREM-related mild OSAS group in terms of anxiety, depression, and daytime sleepiness. METHODS:A total of 166 patients with mild OSAS (72 patients with REM-related and 94 NREM-related OSAS) participated in the study. Hospital Anxiety-Depression Scale (HADS) and Epworth Sleepiness Scale (ESS) questionnaires were completed by both groups. RESULTS:Anxiety and depression scores were significantly higher in patients with REM-related OSAS in comparison to the NREM-related OSAS group (p = 0.01, p = 0.02 respectively). There was no statistically significant difference between the two groups in terms of ESS scores (p = 0.60). CONCLUSION:The results of our study suggest that patients with REM-related OSAS have higher rates of depression and anxiety compared to non-REM-related OSAS patients and this may adversely affect quality of life. It may be possible to prevent psychiatric complications, such as depression and anxiety, by administering treatments that reduce REM sleep duration and intensity in patients with REM-related OSAS. 10.1007/s11325-019-01838-y
    REM-related obstructive sleep apnea: when does it matter? Effect on motor memory consolidation versus emotional health. Djonlagic Ina,Guo Meng,Igue Moroke,Malhotra Atul,Stickgold Robert Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine STUDY OBJECTIVES:The clinical importance of obstructive sleep apnea, which can be prevalent during rapid eye movement (REM) sleep, is unclear. The current study examines the effect of REM-related obstructive sleep apnea on motor memory consolidation as well as on mood states. METHODS:We compared performance on the motor sequence task (MST), psychomotor vigilance test (PVT), Functional Outcomes of Sleep Questionnaire, and the Profile of Mood State (POMS) survey between 3 groups: healthy controls (n = 18), REM-exclusive OSA (n = 17), and patients with OSA with respiratory events throughout REM and non-rapid eye movement (NREM) sleep (n = 18). RESULTS:As expected, performance on the MST improved overnight in the healthy control group. An improvement which was similar in magnitude was also observed in the REM-exclusive OSA group whereas patients with similar OSA during REM and NREM sleep showed reduced overnight memory consolidation. Consistent with these results, we found a correlation between overnight MST improvement and the apnea hypopnea index during NREM sleep (P = .041), but not during REM sleep (P = .424). However, patients with REM-exclusive apnea demonstrated the most negative emotions based on scoring highest on the POMS survey (P = .019). CONCLUSIONS:Our results provide evidence that although apneas occurring only during REM sleep do not have an effect on the encoding and stabilization of motor sequence memories, they are deleterious for emotional health. 10.5664/jcsm.8210
    REM sleep vs exploratory wakefulness: Alternatives within adult 'sleep debt'? Horne Jim Sleep medicine reviews Our declining sleep duration over early human infant development is largely through REM sleep (REM), loss, not of nonREM. It coincides with the infant's increasing locomotion providing for multisensory inputs ('exploratory wakefulness' - EW), together facilitating neural restructuring and behavioural adaptations ('neuroplasticity'). EW also involves curiosity, novelty, navigation, spatial memory, associated emotions, and feeding; all having brain processes particularly active in REM. It is proposed that: 1) REM is a proxy for EW in facilitating neuroplasticity; 2) necessitating REM having a locomotor output, actively inhibited (the atonia); 3) human adults retain many (neotenous) infant characteristics including large amounts of REM towards the end of usual sleep, where REM's qualitative changes indicate reduced sleep pressure, 4) as in infancy, some of our adult REM remains replaceable by EW (without REM rebounds), mostly in this final REM episode whenever EW need prevails. Accordingly, our adult sleep duration is adaptable to habitual shortening via this REM episode substituted by purposeful EW, which could provide extra (day) light exposure for circadian synchrony. Such processes may underlie seasonally shorter (6 h) sleep, eg in hunter-gather people. This flexibility of REM questions the extent of our western 'chronic sleep debt'. Evidence is provided to counter claims that this absent REM would cause obesity and related disorders. 200w. 10.1016/j.smrv.2019.101252
    An updated review of pediatric drug-induced sleep endoscopy. Wilcox Lyndy J,Bergeron Mathieu,Reghunathan Saranya,Ishman Stacey L Laryngoscope investigative otolaryngology Objectives:Drug-induced sleep endoscopy (DISE) involves assessment of the upper airway using a flexible endoscope while patients are in a pharmacologically-induced sleep-like state. The aim of this article is to review the current literature regarding the role of DISE in children with obstructive sleep apnea (OSA). The indications, typical anesthetic protocol, comparison to other diagnostic modalities, scoring systems, and outcomes are discussed. Methods:A comprehensive review of literature regarding pediatric DISE up through May 2017 was performed. Results:DISE provides a thorough evaluation of sites of obstruction during sedation. It is typically indicated for children with persistent OSA after tonsillectomy, those with OSA without tonsillar hypertrophy, children with risk factors predisposing then to multiple sites of obstruction, or when sleep-state dependent laryngomalacia is suspected. The dexmedotomidine and ketamine protocol, which replicates non-REM sleep, appears to be safe and is often used for pediatric DISE, although propofol is the most commonly employed agent for DISE in adults. Six different scoring systems (VOTE, SERS, Chan, Bachar, Fishman, Boudewyns) have been used to report pediatric DISE findings, but none is universally accepted. Conclusions:DISE is a safe and useful technique to assess levels of obstruction in children. There is currently no universally-accepted anesthetic protocol or scoring system for pediatric DISE, but both will be necessary in order to provide a consistent method to report findings, enhance communication among providers and optimize surgical outcomes. Level of Evidence:N/A. 10.1002/lio2.118
    Sleep state distribution of obstructive events in children: is obstructive sleep apnoea really a rapid eye movement sleep-related condition? Verginis Nicole,Jolley Damien,Horne Rosemary S C,Davey Margot J,Nixon Gillian M Journal of sleep research Obstructive sleep apnoea (OSA) in children is commonly considered to occur predominantly in rapid eye movement (REM) sleep, but clinical experience suggests that this is not universally the case. We hypothesized that there would be a subgroup of children with OSA who have non-REM (NREM) predominance of obstructive events and that these children share certain clinical characteristics. Thus, we aimed to compare the obstructive apnoea-hypopnoea index (OAHI) in REM versus NREM sleep and to assess factors influencing the distribution of events by sleep state. Polysomnography (PSG) recordings of 102 children aged 0-18 years with moderate to severe OSA (OAHI >or=5 h(-1)) were reviewed. OAHI was calculated separately for REM and NREM sleep. A REM predominance index (RPI) was determined using log transformation [RPI = log (REM OAHI + 0.5) - log (NREM OAHI + 0.5)] and compared with possible influencing factors using multiple linear regression. Analysis showed that obstructive events were more common in REM sleep (median REM OAHI 21.4 h(-1), median NREM OAHI 8.3 h(-1), P < 0.001). Mean RPI was significantly greater than zero (P = 0.003). However, a substantial minority of children (30.4%) had a higher NREM than REM OAHI. The factors that were related significantly to NREM predominance were older age (P = 0.02), higher arousal index (P < 0.001) and higher SpO(2) nadir (P < 0.001). Our findings demonstrate that while OSA is a REM sleep-related problem in the majority of children, there is a significant subset of children with NREM predominance of obstructive events. This finding highlights the importance of considering sleep state distribution of events in studies of the pathophysiology and outcomes of OSA in childhood. 10.1111/j.1365-2869.2009.00760.x
    Effectiveness of pediatric drug-induced sleep endoscopy for REM-predominant obstructive sleep apnea. Smith David F,He Shan,Peddireddy Nithin S,Vairavan Manickam P,Heubi Christine H,Shott Sally R,Cohen Aliza P,Ishman Stacey L Sleep & breathing = Schlaf & Atmung STUDY OBJECTIVES:Because dexmedetomidine (DEX)-induced sedation mimics non-rapid eye movement (NREM) sleep, its utility in sedating children with REM-predominant disease is unclear. We sought to determine the effectiveness of pediatric drug-induced sleep endoscopy (DISE) using DEX and ketamine for children with REM-predominant OSA, specifically whether or not at least one site of obstruction could be identified. METHODS:A retrospective case series of children without tonsillar hypertrophy undergoing DISE at a tertiary pediatric hospital from 10/2013 through 9/2015 who underwent subsequent surgery to address OSA with polysomnography (PSG) before and after. RESULTS:We included 56 children, mean age 5.6±5.4 years, age range 0.1-17.4 years, mean BMI 20.3±7.4 kg/m2 (76±29 percentile). At least one site of obstruction was identified in all patients, regardless of REM- or NREM-predominance. The mean obstructive apnea-hypopnea index (oAHI) improved (12.6 ± 10.7 to 9.0 ± 14.0 events/h) in children with REM-predominant (P = 0.013) and NREM-predominant disease (21.3 ± 18.9 to 10.3 ± 16.2 events/h) (P = 0.008). The proportion of children with a postoperative oAHI < 5 was 53% and 55% for REM- and NREMpredominant OSA, respectively. Unlike children with NREM-predominant disease, children with REM-predominant disease had significant improvement in the mean saturation nadir (P < 0.001), total sleep time (P = 0.006), and sleep efficiency (P = 0.015). CONCLUSIONS:For children with OSA without tonsillar hypertrophy, DISE using DEX/ketamine was useful to predict at least one site of obstruction, even for those with REM-predominant OSA. DISE-directed outcomes resulted in significant improvements in mean oAHI, total sleep time, sleep efficiency, saturation nadir, and the proportion with oAHI < 5, after surgery for some children with REM-predominant disease. 10.1007/s11325-020-02056-7