The Role of NREM Sleep Instability in Child Cognitive Performance
649 NREM Sleep Instability in Child Cognitive Performance-Bruni et al activity identifies the interval that separates the repetitive elements (i.e., phase B). The alternation between the transient events and the background electrical activity is most likely an expression of arousal instability/stability. The relative proportions of SWA and faster EEG rhythms allow the subdivision of the A-phase of CAP into A1, A2, and A3 subtypes. The A1 subtype is characterized by a predominance of
... slow waves (EEG synchrony), whereas the A3 subtype has a predominance of fast low-amplitude rhythms (EEG desynchrony). The A2 subtype is a mixture of slow and fast EEG rhythms. A1 is the most common subtype of CAP, normally accounting for the majority of all CAP A-phases during normal sleep, occurring approximately 200-400 times per night. 2 In adults, CAP variables have been associated with neurocognitive performance. Aricò et al., 3 in 8 healthy adults, reported that higher CAP A1 rate was correlated with higher verbal fluency, working memory, and both delayed recall and recognition of words; while higher CAP A2 and A3 were associated with worse visual/nonverbal performance. Ferri et al., 4 in 15 healthy adults, investigated the impact of sleep microfragmentation on spatial attention, selective attention cognitive flexibility, visuospatial processing, and inhibition/perceptuoattentional processing. Ferri's group reported few significant relationships, but a trend for higher CAP A1 to be associated with better neurocognitive performance, and higher CAP A3 and (to lesser extent) CAP A2 to be associated with worse neurocognitive performance. In 10 healthy adults, increased CAP A1 following a learning task has been associated with improved motor learning, 5 and a higher CAP rate has been reported in one young adult with superior memory. 6 NREM SLEEP INSTABILITY IN CHILD COGNITIVE PERFORMANCE http://dx.Study Objectives: Based on recent reports of the involvement of cyclic alternating pattern (CAP) in cognitive functioning in adults, we investigated the association between CAP parameters and cognitive performance in healthy children. Design: Polysomnographic assessment and standardized neurocognitive testing in healthy children. Settings: Sleep laboratory. Participants: Forty-two children aged 7.6 ± 2.7 years, with an even distribution of body mass percentile (58.5 ± 25.5) and SES reflective of national norms. Measurements: Analysis of sleep macrostructure following the R&K criteria and of cyclic alternating pattern (CAP). The neurocognitive tests were the Stanford Binet Intelligence Scale (5 th edition) and a Neuropsychological Developmental Assessment (NEPSY) Results: Fluid reasoning ability was positively associated with CAP rate, particularly during SWS and with A1 total index and A1 index in SWS. Regression analysis, controlling for age and SES, showed that CAP rate in SWS and A1 index in SWS were significant predictors of nonverbal fluid reasoning, explaining 24% and 22% of the variance in test scores, respectively. Conclusion: This study shows that CAP analysis provides important insights on the role of EEG slow oscillations (CAP A1) in cognitive performance. Children with higher cognitive efficiency showed an increase of phase A1 in total sleep and in SWS Citation: Bruni O; Kohler M; Novelli L; Kennedy D; Lushington K; Martin J; Ferri R. The role of NREM sleep instability in child cognitive performance. SLEEP 2012;35(5):649-656.