title: Pediatric periodic limb movement disorder: sleep symptom and polysomnographic correlates compared to obstructive sleep apnea.
abstract: OBJECTIVE
  Although periodic limb movements in sleep (PLMS) have been described in multiple pediatric publications, periodic limb movement disorder (PLMD) has not. The aims of this study were to describe the prevalence, sleep-related correlates, and polysomnographic correlates of PLMD in a large pediatric case series, and compare these to pediatric obstructive sleep apnea (OSA).
  
  
  METHODS
  All PLMD cases (defined by International Classification of Sleep Disorders, 2nd edition criteria + respiratory disturbance index [RDI] < 3) and OSA cases (defined by RDI ≥ 3 + PLMS < 5), from a single pediatric sleep practice, over a 2-year time span, were included. Chart, questionnaire, and polysomnographic data were compiled. Of 468 referred children, 66 PLMD cases were identified (14%).
  
  
  RESULTS
  The PLMD cases, mean age 8.1 years (range 1-17), were clinically characterized by frequent sleep onset and maintenance problems, difficulty awakening, restless sleep, leg pain/discomfort at night, and parasomnias. Compared to 90 OSA children, those with PLMD had a history of significantly more sleep onset and maintenance problems, leg pain/discomfort at night, parasomnias, getting out of bed at night, and family history of restless legs syndrome. Polysomnographically, PLMD cases had more awakenings, stage 1 sleep, stage shifts, and spontaneous arousals.
  
  
  CONCLUSIONS
  These data indicate that pediatric PLMD has important clinical and polysomnographic correlates. In addition, PLMD has many characteristics that are different from pediatric OSA, suggesting that PLMD is a distinct pediatric sleep disorder, of which clinicians should be aware.
authors.affiliation: The University of North Carolina-Charlotte, Charlotte, NC, USA. dpicchie@illinois.edu
authors.forename: Jeannine L
authors.initials: JL
authors.lastname: Gingras
authors.forename: Jane F
authors.initials: JF
authors.lastname: Gaultney
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Picchietti
mesh_terms: D017677:Age Distribution; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D015897:Comorbidity; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D008297:Male; D020189:Nocturnal Myoclonus Syndrome / Q000175:diagnosis* / Q000453:epidemiology*; D017286:Polysomnography / Q000379:methods; D015995:Prevalence; D012148:Restless Legs Syndrome / Q000175:diagnosis / Q000453:epidemiology; D012189:Retrospective Studies; D012720:Severity of Illness Index; D017678:Sex Distribution; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis* / Q000453:epidemiology*; D012893:Sleep Wake Disorders / Q000175:diagnosis / Q000453:epidemiology*