Cyclic alternating pattern in peripubertal children

Objectives: The aim of this study is to complement the data on the expression and characteristics of cyclic alternating pattern (CAP) events in children, specifically in the peripubertal age group of 8 to 12 years and to analyze the association of CAP events with arousals. The study of CAP and arousal is a useful tool for assessing sleep instability and fragmentation in children. Design: Descriptive study. Participants: Ten sex-matched healthy children, aged 8 to 12 years, underwent standard polysomnography after 1 adaptation night in the sleep laboratory. Sleep stages, CAP, and arousals were analyzed according to standard international rules. Results: The mean CAP rate was 62.1% +/- 10.8% and the mean CAP cycle duration, 24.6 +/- 2.1 minutes. CAP A1 phase was the most numerous (85.5% +/- 3.9%), whereas the A2 phase was 9.1% +/- 4.7%, and the A3 phase as 5% +/- 2.3%, (P < .01). Differences between boys and girls were detected by analysis of variance, namely increases of phase A2 and A3 subtypes in girls (P < .001). Stronger phase A1 subtype expression in slow-wave sleep was verified in both sexes. Positive correlation between electroencephalogram arousals and the sum of phase A2 and A3 subtypes was also present. The overall CAP rate is higher in this age group than the rate previously reported in children aged 6 to 10 years (62.1% +/- 10.8% vs 33.4% +/- 5.3%). Conclusions: Our study provides normative data on CAP in children aged 8 to 12 years and indicates that age and Tanner stages must both be considered when investigating peripubertal children.