title: Characterization of REM sleep without atonia in patients with narcolepsy and idiopathic hypersomnia using AASM scoring manual criteria.
abstract: BACKGROUND
  The AASM Manual for the Scoring of Sleep and Associated Events (Manual) has provided standardized definitions for tonic and phasic REM sleep without atonia (RSWA). This study used Manual criteria to characterize REM sleep in patients with narcolepsy and idiopathic hypersomnia (IH).
  
  
  METHODS
  A retrospective review of PSG data from ICSD-2 defined patients with narcolepsy or IH, performed by two board certified sleep medicine physicians. Data compiled included REM sleep epochs and the presence in REM sleep of epochs scored as sustained muscle activity (tonic), and excessive transient muscle activity (phasic) as defined by Manual criteria.
  
  
  RESULTS
  PSG data from 8 narcolepsy patients (mean age: 27.5 years; age range: 11-55) showed mean ± standard deviation values for: total REM sleep epochs 205 ± 46.1; RSWA/ phasic epochs 56.1 ± 25.4; and RSWA/tonic epochs 15.0 ± 10.7. PSG data from 8 IH patients (mean age: 33.1 years; age range: 20-57) showed mean ± standard deviation values of total REM sleep epochs 163.8 ± 67.9; RSWA/phasic epochs 6.2 ± 3.5; and RSWA/tonic epochs 0.2 ± 0.4. Comparison revealed intergroup differences in phasic REM sleep (p < 0.01) and tonic REM sleep (p < 0.01) were significantly increased in narcoleptics compared to IH.
  
  
  CONCLUSIONS
  Our retrospective analysis showed that RSWA phasic activity and RSWA tonic activity are significantly increased in patients meeting ICSD-2 criteria for narcolepsy compared to patients meeting ICSD-2 criteria for IH. This robust difference, with further validation, could be useful as electrophysiological criteria differentiating the two disorders and understanding the physiological differences.
authors.affiliation: Department of Neurology, Division of Sleep Medicine, Louisiana State University School of Medicine Shreveport, LA 71103, USA. lordydel@yahoo.com
authors.forename: Lourdes M
authors.initials: LM
authors.lastname: DelRosso
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Chesson
authors.forename: Romy
authors.initials: R
authors.lastname: Hoque
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D002648:Child; D005260:Female; D006801:Humans; D020177:Idiopathic Hypersomnia / Q000150:complications* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009290:Narcolepsy / Q000150:complications* / Q000503:physiopathology; D015588:Observer Variation; D017286:Polysomnography / Q000379:methods*; D020187:REM Sleep Behavior Disorder / Q000150:complications* / Q000175:diagnosis* / Q000503:physiopathology; D012189:Retrospective Studies; D056508:Sleep Medicine Specialty / Q000379:methods; D012895:Sleep, REM / Q000502:physiology*; D012955:Societies, Medical; D014481:United States; D055815:Young Adult
keywords: Narcolepsy; REM sleep without atonia; idiopathic hypersomnia; phasic; rapid eye movement sleep; tonic