Growing pains and periodic limb movements of sleep in children.

AIM: To investigate whether there was any association between growing pains (GP) and periodic limb movements of sleep (PLMS) in children referred for polysomnography (PSG), in light of the possible shared genetic determinants between GP and restless legs syndrome. METHODS: Records of all 903 children who underwent PSG at a paediatric hospital between January 2009 and May 2010 were retrospectively reviewed. Children aged 3-16 years, without neuromuscular or neurological/developmental disorders who were seen by a single sleep physician were included in the analysis. Data extracted included: current GP, PLMS index, mixed obstructive apnoea/hypopnoea index and patient demographics. GP was diagnosed in the pre-PSG consultation. RESULTS: GP was recorded in 43 of the eligible 230 children referred for PSG of whom 25.6% had a PLMS index ≥ 5/h, significantly higher than in the children without GP (10.2%) (odds ratio 3.04, χ(2) = 6.0, P = 0.014). The adjusted odds ratio for the association between GP and PLMS remained significant at 2.53 (95% CI 1.1-6.1, P < 0.05). A PLMS index ≥ 5/h was recorded in 30 of the 230 participants. GP and PLMS were also significantly multivariately associated with restlessness as the indication for PSG. CONCLUSIONS: Children with GP were three times more likely to have a PLMS index ≥ 5/h than children without GP on PSG. These results suggest that GP may be associated with PLMS, giving greater support for the hypothesis that GP might lie on the phenotypic spectrum of restless legs syndrome.

Parental symptom report and periodic limb movements of sleep in children.

STUDY OBJECTIVES: To examine the prevalence of raised periodic limb movements of sleep (PLMS) index in children referred for polysomnography (PSG) and whether parental report of symptoms correlates with objective measurement during PSG. METHODS: Records of children undergoing PSG from January 2006 to July 2006 were retrospectively reviewed. At their initial sleep clinic visit, parents had been asked whether their child was restless or moved their legs excessively during sleep. Their response to these questions was compared to the child's PLMS index (number of periodic limb movements per hour) during a full PSG. PLMS were scored according to internationally accepted criteria. RESULTS: Data were examined for 101 children (60 male) with mean age 6.5 years (range 1.2 to 17.6 years). Excessive leg movements were reported by parents in 50% and restlessness in 73%. A raised PLMS index (defined as > or = 5 per hour) was noted in 10 cases (prevalence 10%). Asking parents about whether their child kicks their legs excessively in sleep had sensitivity 50%, specificity 51%, positive predictive value (PPV) 10%, negative predictive value (NPV) 90% and positive likelihood ratio (LR+) 1.02 when compared to objective analysis. Asking parents about whether their child is restless in sleep had sensitivity 70%, specificity 26%, PPV 9%, NPV 89% and LR+ 0.95. CONCLUSIONS: Asking parents about their child's symptoms is not an accurate predictor of raised PLMS index. We recommend that leg electromyography be used in all pediatric sleep studies to record PLMS.

Incidence of sleep disorders in children with presumed normal variant short stature.

OBJECTIVE: To determine whether unrecognized obstructive sleep apnoea (OSA) is present in some children diagnosed with normal variant short stature. METHODS: One hundred and fifty-eight children aged less than 15 years and previously diagnosed with familial short stature or constitutional delay of growth were identified from the endocrine clinic database. A validated, standardized questionnaire designed to screen for symptoms of sleep disorders in children was mailed to the parents of eligible children. RESULTS: Fifty-three questionnaires were returned. Fifteen of these had an abnormal score (greater than the mean + three standard deviations in 1157 normal control children). Of these, 10 agreed to a sleep study. Overnight polysomnography showed no evidence of OSA or other sleep/breathing disorders. However, five (half) children showed frequent periodic leg movements of 6.3, 9.2, 9.4, 10.2 and 15.4 per h (adult normal <5 per h). CONCLUSIONS: We did not find OSA among a group of children with normal variant short stature. However, we found frequent periodic limb movements during sleep in a large proportion of the subjects, the significance of which remains to be determined.