title: The first phase of nocturnal sleep in mentally retarded children.
abstract: The first phase of sleep observed in 104 mentally retarded children (from 3 months to 8 years of age) was studied throughout nocturnal sleep, and the following results were obtained. In 4 out of 104 subjects, REM sleep onset was observed, and in the remaining 100 subjects NREM sleep onset was found at the first wakefulness-sleep transition of the night. Following awakenings (lasting 4 min or more) during the night, 170 (51.7%) out of a total of 329 samples were REM sleep onset, and 159 (48.3%) showed NREM sleep onset. The phases of sleep onset and those following awakenings evidenced no correlation between the frequency of NREM sleep onset and DQ or clinical EEG, whereas a positive correlation was found between the frequency of NREM sleep onset and age.
mesh_terms: D002648:Child; D002657:Child Development; D002675:Child, Preschool; D004569:Electroencephalography; D005260:Female; D006801:Humans; D007223:Infant; D008607:Intellectual Disability / Q000503:physiopathology*; D008297:Male; D012890:Sleep / Q000502:physiology*; D012895:Sleep, REM / Q000502:physiology; D014851:Wakefulness / Q000502:physiology