title: Periodic leg movements during sleep in children scheduled for adenotonsillectomy: frequency, persistence, and impact.
abstract: OBJECTIVE
  The aim of this study was to assess the frequency and potential clinical impact of periodic leg movements during sleep (PLMS), with or without arousals, as recorded incidentally from children before and after adenotonsillectomy (AT).
  
  
  METHODS
  Children scheduled for AT for any clinical indications who participated in the Washtenaw County Adenotonsillectomy Cohort II were studied at enrollment and again 6 months thereafter. Assessments included laboratory-based polysomnography, a Multiple Sleep Latency Test (MSLT), parent-completed behavioral rating scales, neuropsychological testing, and psychiatric evaluation.
  
  
  RESULTS
  Participants included 144 children (81 boys) aged 3-12 years. Children generally showed mild to moderate obstructive sleep apnea (median respiratory disturbance index 4.5 (Q1 = 2.0, Q3 = 9.5)) at baseline, and 15 subjects (10%) had at least five periodic leg movements per hour of sleep (PLMI ≥ 5). After surgery, 21 (15%) of n = 137 subjects who had follow-up studies showed PLMI ≥ 5 (p = 0.0067). Improvements were noted after surgery in the respiratory disturbance index; insomnia symptoms; sleepiness symptoms; mean sleep latencies; hyperactive behavior; memory, learning, attention, and executive functioning on NEPSY assessments; and frequency of attention-deficit/hyperactivity disorder (DSM-IV criteria). However, PLMI ≥ 5 failed to show associations with worse morbidity in these domains at baseline or follow-up. New appearance of PLMI ≥ 5 after surgery failed to predict worsening of these morbidities (all p > 0.05), with only one exception (NEPSY) where the magnitude of association was nonetheless negligible. Similar findings emerged for periodic leg movements with arousals (PLMAI ≥ 1).
  
  
  CONCLUSIONS
  PLMS, with and without arousals, become more common after AT in children. However, results in this setting did not suggest substantial clinical impact.
authors.affiliation: Sleep Disorders Center and Department of Neurology, University of Michigan, Ann Arbor, MI, USA. Electronic address: chervin@umich.edu.
authors.forename: Ronald D
authors.initials: RD
authors.lastname: Chervin
authors.affiliation: Sleep Disorders Center, University of Michigan, Ann Arbor, MI, USA; Department of Psychiatry, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
authors.forename: Seockhoon
authors.initials: S
authors.lastname: Chung
authors.affiliation: Sleep Disorders Center and Departments of Neurology, Oral and Maxillofacial Surgery, and Obstetrics and Gynecology, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Louise M
authors.initials: LM
authors.lastname: O'Brien
authors.affiliation: Sleep Disorders Center and Division of Pediatric Neurology, Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Timothy F
authors.initials: TF
authors.lastname: Hoban
authors.affiliation: Sleep Disorders Center and Division of Pediatric Otolaryngology, Department of Otolaryngology and Head and Neck Surgery, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Susan L
authors.initials: SL
authors.lastname: Garetz
authors.affiliation: Sleep Disorders Center and Department of Neurology, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Deborah L
authors.initials: DL
authors.lastname: Ruzicka
authors.affiliation: Department of Biostatistics, University of Michigan School of Public Health, Ann Arbor, MI, USA.
authors.forename: Kenneth E
authors.initials: KE
authors.lastname: Guire
authors.affiliation: Division of Neuropsychology, Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Elise K
authors.initials: EK
authors.lastname: Hodges
authors.affiliation: Division of Child Behavioral Health, Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Barbara T
authors.initials: BT
authors.lastname: Felt
authors.affiliation: Division of Neuropsychology, Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Bruno J
authors.initials: BJ
authors.lastname: Giordani
authors.affiliation: Department of Psychiatry, Central Michigan University, Mount Pleasant, MI, USA.
authors.forename: James E
authors.initials: JE
authors.lastname: Dillon
mesh_terms: D000233:Adenoidectomy / Q000009:adverse effects / Q000706:statistics & numerical data; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D020189:Nocturnal Myoclonus Syndrome / Q000453:epidemiology* / Q000209:etiology; D017286:Polysomnography; D007319:Sleep Initiation and Maintenance Disorders / Q000453:epidemiology; D014068:Tonsillectomy / Q000009:adverse effects / Q000706:statistics & numerical data; D014851:Wakefulness
keywords: Arousals; Child; Cognition; Periodic leg movements; Periodic limb movement disorder; Polysomnography; Sleep apnea, obstructive; Sleepiness