Primary sleep enuresis in childhood. Polysomnographic evidences of sleep stage and time modulation.

The objective of this study was to evaluate enuretic events and its relations to sleep stages, sleep cycles and time durations in a selected group of children with primary essential sleep enuresis. We evaluated 18 patients with mean age of 8.2 years old (ranging from 5 to 12 years); 10 were males and 8 females (n.s.). They were referred to the Sleep Disorders Center with the specific complaint of enuresis since the first years of life (primary). Pediatric, urologic and neurologic workup did not show objective abnormalities (essential). The standard all-night polysomnography including an enuresis sensor attached to the shorts in the crotch area was performed. Only enuretic events nights were included. All were drug free patients for two weeks prior to polysomnography. In this report, only one polysomnography per patient was considered. The enuretic events were phase related, occurring predominantly in non-REM (NREM) sleep (p < 0.05). There was no predominance of enuretic events among the NREM stages (n.s.). A tendency of these events to occur in the first two sleep cycles was detected but may be due to the longer duration of these cycles. The events were time modulated, adjusted to a normal distribution with a mean of 213.4 min of recording time.