title: Do periodic arm movements during sleep exist in healthy subjects? A polysomnographic study.
abstract: BACKGROUND
  Despite several polysomnographic studies on periodic leg movements (PLM) in healthy sleep, data on the prevalence and characteristics of periodic arm movements (PAM) in normal subjects are lacking. We aimed to investigate PAM and their association with PLM during wakefulness and sleep in healthy subjects.
  
  
  METHODS
  Ninety-one participants underwent video-polysomnography according to American Academy of Sleep Medicine 2007 criteria. In addition to standard electromyographic registration, data for both flexor digitorum superficialis muscles were recorded.
  
  
  RESULTS
  Sixty-two subjects (68.1%) had a PAM index during wakefulness >5/h (median PAM index during wakefulness, 8.8/h; range, 0-77). Seven subjects (7.7%) had a PAM index >5/h during sleep (median PAM index during sleep, 0.7/h; range, 0-47.4). In 14% of cases, PAM during wakefulness were coincident with PLM during wakefulness. During sleep, this coincidence was not evident. The correlation between PAM and PLM was weak to moderate (during wakefulness: Spearman's ρ = 0.576, P < 0.001; during sleep: Spearman's ρ = 0.222, P = 0.036).
  
  
  CONCLUSIONS
  In healthy subjects, PAM occur predominantly during wakefulness with no apparent true periodicity. In contrast to classical PLM, some PAM may not present a true periodic phenomenon, but rather random voluntary movements meeting the wide range of periodicity criteria for PLM.
authors.affiliation: Department of Neurology, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: David
authors.initials: D
authors.lastname: Gabelia
authors.affiliation: Department of Neurology, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Thomas
authors.initials: T
authors.lastname: Mitterling
authors.affiliation: Department of Neurology, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Birgit
authors.initials: B
authors.lastname: Högl
authors.affiliation: Department of Neurology, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Gregor K
authors.initials: GK
authors.lastname: Wenning
authors.affiliation: Department of Neurology, Innsbruck Medical University, Innsbruck, Austria. Electronic address: birgit.frauscher@i-med.ac.at.
authors.forename: Birgit
authors.initials: B
authors.lastname: Frauscher
mesh_terms: D000328:Adult; D000368:Aged; D001132:Arm; D001143:Arousal; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020189:Nocturnal Myoclonus Syndrome / Q000175:diagnosis*; D017286:Polysomnography; D012016:Reference Values; D012894:Sleep Stages; D014741:Video Recording; D014851:Wakefulness; D055815:Young Adult
keywords: AASM 2.0; Healthy subjects; Periodic arm movements; Polysomnography; Sleep