title: Periodic limb movements and disrupted sleep in children with sickle cell disease.
abstract: OBJECTIVE
  To describe the rate, distribution and correlates of periodic limb movements in sleep (PLMS) in children with sickle cell disease (SCD).
  
  
  METHODS
  Prospective, cross-sectional.
  
  
  METHODS
  Hospital-based sleep laboratory.
  
  
  METHODS
  Sixty-four children aged 2-18 years with SCD, hemoglobin SS-type who had an overnight polysomnogram and a parent-completed Pediatric Sleep Questionnaire. Mean age was 8.4 years (SD 4.8); 50% were male.
  
  
  METHODS
  N/A.
  
  
  RESULTS
  The mean PLMS index was 3.7 (6.6) and ranged from 0 to 31.8, with 23.4% of the sample having PLMS ≥ 5/h. Sleep efficiency was decreased (P = 0.03), and the total arousal index (P = 0.003) and PLMS arousal index (P < 0.001) were increased in children with PLMS ≥ 5/h compared to those with PLMS < 5/h. PLMS were most frequent in NREM stage 2 sleep and during the fourth hour of sleep. Inter-movement interval duration peaked at 25-30 s. "Growing pains worst in bed" or "restlessness of the legs", suggesting restless legs syndrome (RLS), were reported in 12.5% of the total sample and were more common in children with elevated PLMS. A PLMS score for identifying elevated PLMS in children, based on items from the Pediatric Sleep Questionnaire, did not significantly predict PLMS ≥ 5/h.
  
  
  CONCLUSIONS
  Elevated PLMS are common in children with SCD and are associated with sleep disruption and symptoms of RLS. Future research into the time structure of PLMS, their causes and consequences, and development of a disease-specific sleep disorders screening questionnaire, is needed in children with SCD.
authors: University of Pennsylvania, Philadelphia, PA, USA.
authors: Valerie E
authors: VE
authors: Rogers
authors: Carole L
authors: CL
authors: Marcus
authors: Abbas F
authors: AF
authors: Jawad
authors: Kim
authors: K
authors: Smith-Whitley
authors: Kwaku
authors: K
authors: Ohene-Frempong
authors: Cheryl
authors: C
authors: Bowdre
authors: Julian
authors: J
authors: Allen
authors: Raanan
authors: R
authors: Arens
authors: Thornton B A
authors: TB
authors: Mason
mesh_terms: D000293:Adolescent; D000755:Anemia, Sickle Cell / Q000150:complications* / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005121:Extremities / Q000503:physiopathology; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009068:Movement; D017286:Polysomnography; D011446:Prospective Studies; D012148:Restless Legs Syndrome / Q000453:epidemiology / Q000209:etiology*; D012894:Sleep Stages / Q000502:physiology*