Prevalence of periodic limb movements during sleep in normal children.

STUDY OBJECTIVES: Although the American Academy of Sleep Medicine (AASM) mandates that periodic limb movements during sleep (PLMS) be scored on every polysomnogram, and considers a periodic limb movement index (PLMI) > 5/h abnormal in children, there is a lack of community-derived data regarding the prevalence of PLMS in children, and no data to support this cutoff value. Therefore, the aim of this study was to determine the prevalence of PLMS in a sample of normal children. DESIGN: Retrospective study. PARTICIPANTS: 195 healthy, non-snoring children aged 5-17 years, recruited from the community, who underwent polysomnography for research purposes. METHODS: PLMS were scored using the AASM 2007 criteria. MEASUREMENTS AND RESULTS: The group age (median [IQR]) was 12.9 [10-15] years, and 58% were male. Sleep architecture was normal, and the obstructive apnea hypopnea index was 0.1 [0-0.3]/h. The median PLMI was 0/h, ranging from 0 to 35.5/h. Fifteen (7.7%) subjects had a PLMI > 5/h, and only 3 (1.5%) met the adult pathologic criterion of more than 15/h. Use of the 95th percentile PLMI cutoff of 7.2/h produced little difference in categorization between groups. Children with a PLMI > 5/h had a higher arousal index than those with a lower PLMI (11.6 [8.8-14.6] vs 8.1 [6.1-9.9]/h, respectively, P = 0.003). CONCLUSIONS: This study provides normative data to the field and supports the clinical periodic limb movement index cutoff of > 5/h based on both prevalence and the correlate of increased sleep fragmentation. Periodic limb movements during sleep are infrequent in normal children recruited from the community. CITATION: Marcus CL, Traylor J, Gallagher PR, Brooks LJ, Huang J, Koren D, Katz L, Mason TB, Tapia IE. Prevalence of periodic limb movements during sleep in normal children.

Enuresis in children with sleep apnea.

OBJECTIVES: To test the hypothesis that the presence of nocturnal enuresis is related to the severity of sleep apnea, we examined the relation between the Respiratory Disturbance Index (RDI, apneas plus hypopneas per hour of sleep) and the presence and severity of enuresis. STUDY DESIGN: All children 4 years of age and older who were referred to our sleep center for suspected sleep disordered breathing (SDB) were asked whether and how frequently they currently wet the bed. All patients underwent full overnight polysomnography (PSG). The relation between RDI and enuresis was examined by chi(2) analysis. A value of P <.05 was considered statistically significant. RESULTS: Ninety boys and 70 girls were studied; 66 children (41%) described current enuresis. At all ages, enuresis was more prevalent in our patients than control patients in the literature. Children with an RDI of < or =1 had a significantly lower prevalence of enuresis (17%) than did children with an RDI >1 (47%) (P <.05). Fourteen percent of children with an RDI < or =1 had frequent enuresis, compared with 32% of children with an RDI >1 (P <.05). There was no significant difference in the prevalence of enuresis in children with an RDI 1 to 5, 5 to 15, or >15 (P =.92). CONCLUSIONS: There is a high prevalence of enuresis in children with suspected sleep-disordered breathing. Children with an RDI >1 were at higher risk for enuresis than children with an RDI < or =1. This may be due to the effects of obstructive sleep apnea on arousal response, bladder pressure, or urinary hormone secretion.