Sleep EEG maps the functional neuroanatomy of executive processes in adolescents born very preterm.
Wehrle Flavia M,Latal Beatrice,O'Gorman Ruth L,Hagmann Cornelia F,Huber Reto
Cortex; a journal devoted to the study of the nervous system and behavior
Executive function deficits are among the most frequent sequela of very preterm birth but the underlying neuronal mechanisms are not fully understood. We used high-density electroencephalography (EEG) recordings during sleep to assess alterations in the functional neuroanatomy of executive processes in adolescents born very preterm. The topographical distribution of sleep slow wave activity (SWA; 1-4.5 Hz EEG power) has previously been used to map cognitive abilities and is known to reflect the intensity of the prior use of the respective neuronal networks. We assessed 38 adolescents born before 32 weeks of gestation [age at assessment: 12.9 (SD: 1.7), range: 10.6-16.7 years] and 43 term-born peers [13.1 (2.0), 10.0-16.9]. Executive function abilities were quantified with a composite score derived from a comprehensive task battery. All-night high-density EEG (128 electrodes) was recorded and SWA of the first hour of sleep was calculated. Abilities were significantly poorer in the very preterm compared to the term-group, particularly, if the tasks demands were high (p < .01). The score was positively correlated with sleep SWA in a cluster of 15 electrodes over frontal and negatively in a cluster of 14 electrodes over central brain regions after controlling for age at assessment and correcting for multiple comparisons. Within the frontal cluster, sleep SWA was higher in very preterm compared to term-born participants when controlling for executive function performance and age at assessment (p = .02). No difference in SWA between very preterm and term-born participants was found for the central cluster (p = .29). Our results demonstrate a local increase of sleep SWA over brain regions associated with executive processes in adolescents born very preterm compared to similarly performing term-born peers. Thus, sleep SWA seems to map the higher effort needed for executive function tasks in adolescents born very preterm.
Slow wave activity and executive dysfunction in children with sleep disordered breathing.
Christiansz Jessica A,Lappin Chloe R,Weichard Aidan J,Nixon Gillian M,Davey Margot J,Horne Rosemary S C,Biggs Sarah N
Sleep & breathing = Schlaf & Atmung
PURPOSE:This study aimed to examine slow wave activity (SWA), a marker of homeostatic regulation, as a potential mechanism linking sleep disordered breathing (SDB) with executive dysfunction in children. METHODS:Executive function domains of working memory, spatial planning, information processing, and sustained attention were assessed using the Cambridge Neuropsychological Test Automated Battery (CANTAB) in children (N = 40; 5-12 years) referred for clinical diagnosis of SDB. Polysomnography records of non-snoring, age-matched controls (N = 34) were retrospectively examined for comparison of SWA. Power spectral analysis of the delta wave determined SWA. Group differences in sleep, respiratory, and SWA outcomes were examined. Mean CANTAB scores were compared to standardized norms and correlated against SWA. RESULTS:Children with SDB showed increased SWA compared to non-snoring controls and scored < 25th percentile for planning accuracy, speed of mental processing, and task efficiency, when compared against population norms. Increasing severity of SDB was associated with an increased difficulty in solving complex tasks and time on task performance. SWA was associated with performance on tasks of early problem solving and efficiency during sustained attention. CONCLUSIONS:SWA, a subtle measure of sleep disruption and sleep regulation, is associated with deficits in problem solving and sustained attention in children with SDB. As current mechanistic theories do not account for deficits observed in children with mild forms of SDB, this study provides a promising alternative.