title: Cyclic alternating pattern in peripubertal children.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  Descriptive study.
  
  
  METHODS
  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.
authors.affiliation: Department of Psychobiology, Federal University of Sao Paulo, Brazil. m.cecilialopes@psicobio.epm.br
authors.forename: Maria Cecilia
authors.initials: MC
authors.lastname: Lopes
authors.forename: Agostinho
authors.initials: A
authors.lastname: Rosa
authors.forename: Suely
authors.initials: S
authors.lastname: Roizenblatt
authors.forename: Christian
authors.initials: C
authors.lastname: Guilleminault
authors.forename: Cassia
authors.initials: C
authors.lastname: Passarelli
authors.forename: Sergio
authors.initials: S
authors.lastname: Tufik
authors.forename: Dalva
authors.initials: D
authors.lastname: Poyares
mesh_terms: D002648:Child; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D010507:Periodicity; D017286:Polysomnography; D020178:Sleep Disorders, Circadian Rhythm / Q000453:epidemiology* / Q000503:physiopathology; D012894:Sleep Stages / Q000502:physiology; D011795:Surveys and Questionnaires