title: Differences in electroencephalographic findings among categories of narcolepsy-spectrum disorders.
abstract: OBJECTIVE
  To clarify the differences in quantitative electroencephalographic (EEG) measures and their relation to clinical symptoms among narcolepsy-spectrum disorders.
  
  
  METHODS
  The enrolled patients were: 28 with narcolepsy with cataplexy (NA-CA); 16 with NA without cataplexy (NA w/o CA) and HLA-DRB1*1501/DQB1*0602 positive (NA w/o CA HLA+); 22 with NA w/o CA and HLA negative (NA w/o CA HLA-); and 22 with idiopathic hypersomnia without long sleep time (IHS w/o LST). Nocturnal polysomnography (n-PSG) and quantitative EEG evaluation, as well as the Multiple Sleep Latency test (MSLT), were conducted for all patients.
  
  
  RESULTS
  Patients with NA-CA or NA w/o CA HLA+ showed lower alpha power, higher delta and theta power during wakefulness, and higher alpha and beta power during rapid eye movement (REM) sleep, compared to those with NA w/o CA HLA- or IHS w/o LST. The former two groups also showed lower sleep efficiency and a higher rate of positivity of REM-related symptoms than the other two groups.
  
  
  CONCLUSIONS
  In narcolepsy, the presence of cataplexy and HLA positivity are associated with EEG slowing during wakefulness and increased fast EEG activity during REM sleep, REM-related symptoms and disrupted nocturnal sleep in narcolepsy.
authors.affiliation: Department of Somnology, Tokyo Medical University, Tokyo, Japan; Department of Life Sciences and Bio-informatics, Division of Biomedical Laboratory Sciences, Graduate School of Health Sciences, Tokyo Medical and Dental University, Tokyo, Japan. Electronic address: taeko_ssi@yahoo.co.jp.
authors.forename: Taeko
authors.initials: T
authors.lastname: Sasai-Sakuma
authors.affiliation: Department of Somnology, Tokyo Medical University, Tokyo, Japan; Japan Somnology Center, Neuropsychiatric Research Institute, Tokyo, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Inoue
mesh_terms: D000328:Adult; D004569:Electroencephalography; D005260:Female; D059866:HLA-DQ beta-Chains / Q000378:metabolism; D059811:HLA-DRB1 Chains / Q000378:metabolism; D006801:Humans; D008297:Male; D009290:Narcolepsy / Q000503:physiopathology*; D017286:Polysomnography; D012895:Sleep, REM / Q000502:physiology; D014851:Wakefulness / Q000502:physiology; D055815:Young Adult
chemical_list: D059866:HLA-DQ beta-Chains; C069051:HLA-DQB1 antigen; D059811:HLA-DRB1 Chains
keywords: Electroencephalogram; HLA-DRB1*1501/DQB1*0602; Idiopathic hypersomnia; Narcolepsy; Nocturnal polysomnography