title: Visually detected NREM Stage 2 sleep spindles in kindergarten children are associated with stress challenge and coping strategies.
abstract: OBJECTIVE
  Sleep EEG spindles are linked to efficient cortical-subcortical connectivity and intellectual abilities. The aim of the present study was to investigate the relationship of spindle activity to psychosocial stress response and coping strategies in healthy kindergarten children.
  
  
  METHODS
  In a cross-sectional study of 41 5-year old kindergarten children we examined stress-induced hypothalamic-pituitary-adrenocortical (HPA) system activity by saliva cortisol measurements and sleep regulation by sleep EEG-monitoring. Stress response was measured during the application of a standardized psychological challenge appropriate at this age. NREM S2 sleep EEG spindles were visually scored and put into relation to coping and HPA activity parameters.
  
  
  RESULTS
  An increased total number of NREM S2 sleep spindles correlated positively with increased high ego-involvement strategies such as "positive emotions". By contrast, total number of NREM S2 sleep spindles correlated negatively with low ego-involvement strategies such as "denial" and "avoidance". Stress induced HPA-activity correlated positively with coping strategies with high ego-involvement; while there was no correlation with low ego-involvement strategies.
  
  
  CONCLUSIONS
  Total number of visually detected NREM S2 sleep spindles is elevated in children with coping involving positive, high ego-involvement; in contrast, low ego-involvement during stress is associated with reduced total number of NREM S2 sleep spindles.
authors.affiliation: Psychiatric Hospital of the University of Basel, Psychiatric Out-Patient Clinic, Basel, Switzerland. thorsten.mikoteit@upkbs.ch
authors.forename: Thorsten
authors.initials: T
authors.lastname: Mikoteit
authors.forename: Serge
authors.initials: S
authors.lastname: Brand
authors.forename: Johannes
authors.initials: J
authors.lastname: Beck
authors.forename: Sonja
authors.initials: S
authors.lastname: Perren
authors.forename: Agnes
authors.initials: A
authors.lastname: von Wyl
authors.forename: Kai
authors.initials: K
authors.lastname: von Klitzing
authors.forename: Edith
authors.initials: E
authors.lastname: Holsboer-Trachsler
authors.forename: Martin
authors.initials: M
authors.lastname: Hatzinger
mesh_terms: D000223:Adaptation, Psychological; D002675:Child, Preschool; D003674:Defense Mechanisms; D003717:Denial, Psychological; D004532:Ego; D004569:Electroencephalography; D004644:Emotions; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis; D007030:Hypothalamo-Hypophyseal System; D008297:Male; D010913:Pituitary-Adrenal System; D017286:Polysomnography; D012463:Saliva / Q000737:chemistry; D012894:Sleep Stages; D013315:Stress, Psychological
chemical_list: D006854:Hydrocortisone