title: Longitudinal study of cognitive function in idiopathic REM sleep behavior disorder.
abstract: OBJECTIVE
  To assess the longitudinal course of cognitive functions in a cohort of patients with idiopathic REM sleep behavior disorder (iRBD).
  
  
  METHODS
  Prospective study with baseline and 2-year follow-up.
  
  
  METHODS
  Sleep disorders center.
  
  
  METHODS
  Twenty-four cognitively asymptomatic iRBD patients (18 M; mean age: 69.5 ± 7.3 y) and 12 sex-, age-, and education-matched healthy subjects.
  
  
  METHODS
  Participants underwent to a video-PSG, a focused neuropsychological evaluation and a neurological examination. Following the first evaluation, subjects were reassessed after a mean interval of 25.8 months.
  
  
  RESULTS
  Executive functions, attention and language were normal at baseline and at 2 year follow-up examination. At baseline, iRBD patients showed poorer performance than controls in delayed verbal memory (story recall test: P = 0.001) and in visuo-constructional abilities (Copy of the Rey-Osterrieth complex figure: P = 0.0005). At follow-up, they not only performed worse than controls in the same tests (story recall: P = 0.0001; Copy of the Rey-Osterrieth complex figure: P = 0.0004), but they also showed an impairment in visuo-spatial learning (Corsi supraspan test; P < 0.0001). ANOVAs showed a significant worsening in visuo-spatial learning over time in RBD compared to controls (P = 0.0001). Furthermore, 3 patients fulfilled the UK Brain Bank criteria for Parkinson disease, but this was unrelated to cognitive deterioration.
  
  
  CONCLUSIONS
  Although no patients developed dementia, the decline observed in some tests involving the memory and visuo-constructional domains in idiopathic RBD suggests the presence of an underlying evolving degenerative process.
authors.affiliation: Sleep Disorders Center, Università Vita-Salute San Raffaele, Milan, Italy. fantini.marialivia@hsr.it
authors.forename: Maria Livia
authors.initials: ML
authors.lastname: Fantini
authors.forename: Elena
authors.initials: E
authors.lastname: Farini
authors.forename: Paola
authors.initials: P
authors.lastname: Ortelli
authors.forename: Marco
authors.initials: M
authors.lastname: Zucconi
authors.forename: Mauro
authors.initials: M
authors.lastname: Manconi
authors.forename: Stefano
authors.initials: S
authors.lastname: Cappa
authors.forename: Luigi
authors.initials: L
authors.lastname: Ferini-Strambi
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D003072:Cognition Disorders / Q000150:complications* / Q000503:physiopathology / Q000523:psychology; D056344:Executive Function / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D017286:Polysomnography; D011446:Prospective Studies; D020187:REM Sleep Behavior Disorder / Q000150:complications* / Q000503:physiopathology / Q000523:psychology; D018709:Statistics, Nonparametric