title: A Polysomnography Study of Kleine-Levin Syndrome in a Single Center.
abstract: BACKGROUND
  Kleine-Levin syndrome (KLS) is a rare sleep disorder characterized by recurrent episodes of hypersomnia. Polysomnographic (PSG) researches of KLS have been reported only in few publications in the past decades. This study aimed to investigate the characteristics of PSG of KLS.
  
  
  METHODS
  This study, which was conducted from March 2010 to July 2014, included seven patients diagnosed with KLS in the Sleep and Wake Disorder Center of Huashan Hospital, Fudan University (Shanghai, China). PSG and multiple sleep latency tests (MSLT) were performed during their episodes and the results were evaluated.
  
  
  RESULTS
  Five of the seven patients were males. The mean age at KLS onset was 15.6 ± 3.6 years. The number of episodes ranged from 2 to 7. The duration of episodes lasted from 4 to 11 days. The sleep architecture and proportion were normal in most of the patients. The average value of mean sleep latency was 6.9 ± 4.1 min. No sleep-onset rapid eye movement (SOREM) was detected in three of the patients, whereas one patient experienced one period of SOREM, and such episodes occurred twice in other two patients.
  
  
  CONCLUSIONS
  We found that sleep architecture and proportion were normal in most KLS patients. However, the results of PSG and MSLT had no specificity for KLS patients.
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200040, China.
authors.forename: Yan-Wen
authors.initials: YW
authors.lastname: Luo
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200040, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Yu
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200040, China.
authors.forename: Lu-Hua
authors.initials: LH
authors.lastname: Yuan
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200040, China.
authors.forename: Guo-Xing
authors.initials: GX
authors.lastname: Zhu
mesh_terms: D000293:Adolescent; D002648:Child; D002681:China; D005260:Female; D006801:Humans; D017593:Kleine-Levin Syndrome / Q000175:diagnosis* / Q000503:physiopathology*; D008297:Male; D017286:Polysomnography / Q000379:methods*; D012189:Retrospective Studies; D012893:Sleep Wake Disorders / Q000503:physiopathology; D012895:Sleep, REM / Q000502:physiology