title: Impaired decision-making in idiopathic REM sleep behavior disorder.
abstract: BACKGROUND
  Patients with REM sleep behavior disorder (RBD) frequently develop Parkinson's disease (PD), which can impair decision-making ability. This study was undertaken to investigate decision-making ability and its relation to olfactory function in patients with idiopathic RBD.
  
  
  METHODS
  This study used the Iowa Gambling Task (IGT) and the Sniffin' Stick Test for examination of 38 patients with idiopathic RBD (iRBD) and 34 age-matched healthy control subjects (HC). Associations between these test results and other clinical RBD variables were also assessed.
  
  
  RESULTS
  Total IGT score and Sniffin' Stick Test scores were significantly lower in the iRBD group than in the HC group. The iRBD group IGT scores in the first, third, and final blocks were significantly lower than those of the HC group. In the iRBD group, no association was found between the total IGT score and the Sniffin' Stick Test score or any clinical RBD variable.
  
  
  CONCLUSIONS
  Impaired decision-making associated with iRBD can herald PD. However, decision-making disability is thought to appear irrespective of olfactory dysfunction and progression of RBD pathology.
authors.affiliation: Japan Somnology Center, Neuropsychiatric Research Institute, Tokyo, Japan. taeko_ssi@yahoo.co.jp
authors.forename: Taeko
authors.initials: T
authors.lastname: Sasai
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Miyamoto
authors.forename: Masayuki
authors.initials: M
authors.lastname: Miyamoto
authors.forename: Masaoki
authors.initials: M
authors.lastname: Iwanami
authors.forename: Takashi
authors.initials: T
authors.lastname: Abe
authors.forename: Masato
authors.initials: M
authors.lastname: Matsuura
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Inoue
mesh_terms: D000368:Aged; D003071:Cognition / Q000502:physiology*; D003657:Decision Making / Q000502:physiology*; D005221:Fatigue / Q000503:physiopathology; D005260:Female; D005715:Gambling / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000503:physiopathology; D020187:REM Sleep Behavior Disorder / Q000503:physiopathology*; D012894:Sleep Stages / Q000502:physiology; D012903:Smell / Q000502:physiology*