title: Risk factors for neurodegeneration in idiopathic rapid eye movement sleep behavior disorder: a multicenter study.
abstract: OBJECTIVE
  To assess whether risk factors for Parkinson disease and dementia with Lewy bodies increase rate of defined neurodegenerative disease in idiopathic rapid eye movement (REM) sleep behavior disorder (RBD).
  
  
  METHODS
  Twelve centers administered a detailed questionnaire assessing risk factors for neurodegenerative synucleinopathy to patients with idiopathic RBD. Variables included demographics, lifestyle factors, pesticide exposures, occupation, comorbid conditions, medication use, family history, and autonomic/motor symptoms. After 4 years of follow-up, patients were assessed for dementia or parkinsonism. Disease risk was assessed with Kaplan-Meier analysis, and epidemiologic variables were compared between convertors and those still idiopathic using logistic regression.
  
  
  RESULTS
  Of 305 patients, follow-up information was available for 279, of whom 93 (33.3%) developed defined neurodegenerative disease. Disease risk was 25% at 3 years and 41% after 5 years. Patients who converted were older (difference = 4.5 years, p < 0.001), with similar sex distribution. Neither caffeine, smoking, nor alcohol exposure predicted conversion. Although occupation was similar between groups, those who converted had a lower likelihood of pesticide exposure (occupational insecticide = 2.3% vs 9.0%). Convertors were more likely to report family history of dementia (odds ratio [OR] = 2.09), without significant differences in Parkinson disease or sleep disorders. Medication exposures and medical history were similar between groups. Autonomic and motor symptoms were more common among those who converted. Risk factors for primary dementia and parkinsonism were generally similar, except for a notably higher clonazepam use in dementia convertors (OR = 2.6).
  
  
  CONCLUSIONS
  Patients with idiopathic RBD are at very high risk of neurodegenerative synucleinopathy. Risk factor profiles between convertors and nonconvertors have both important commonalities and differences.
authors.affiliation: Department of Neurology, McGill University, Montreal General Hospital, Montreal, Quebec, Canada; Sleep Medicine Center for Advanced Studies, Sacred Heart Hospital of Montreal, Montreal, Quebec, Canada.
authors.forename: Ronald B
authors.initials: RB
authors.lastname: Postuma
authors.forename: Alex
authors.initials: A
authors.lastname: Iranzo
authors.forename: Birgit
authors.initials: B
authors.lastname: Hogl
authors.forename: Isabelle
authors.initials: I
authors.lastname: Arnulf
authors.forename: Luigi
authors.initials: L
authors.lastname: Ferini-Strambi
authors.forename: Raffaele
authors.initials: R
authors.lastname: Manni
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Miyamoto
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Oertel
authors.forename: Yves
authors.initials: Y
authors.lastname: Dauvilliers
authors.forename: Yo-El
authors.initials: YE
authors.lastname: Ju
authors.forename: Monica
authors.initials: M
authors.lastname: Puligheddu
authors.forename: Karel
authors.initials: K
authors.lastname: Sonka
authors.forename: Amelie
authors.initials: A
authors.lastname: Pelletier
authors.forename: Juan
authors.initials: J
authors.lastname: Santamaria
authors.forename: Birgit
authors.initials: B
authors.lastname: Frauscher
authors.forename: Smaranda
authors.initials: S
authors.lastname: Leu-Semenescu
authors.forename: Marco
authors.initials: M
authors.lastname: Zucconi
authors.forename: Michele
authors.initials: M
authors.lastname: Terzaghi
authors.forename: Masayuki
authors.initials: M
authors.lastname: Miyamoto
authors.forename: Marcus M
authors.initials: MM
authors.lastname: Unger
authors.forename: Bertrand
authors.initials: B
authors.lastname: Carlander
authors.forename: Maria-Livia
authors.initials: ML
authors.lastname: Fantini
authors.forename: Jacques Y
authors.initials: JY
authors.lastname: Montplaisir
mesh_terms: D000368:Aged; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D019636:Neurodegenerative Diseases / Q000175:diagnosis* / Q000453:epidemiology*; D020187:REM Sleep Behavior Disorder / Q000175:diagnosis* / Q000453:epidemiology*; D012307:Risk Factors; D011795:Surveys and Questionnaires