title: Olfactory dysfunction predicts early transition to a Lewy body disease in idiopathic RBD.
abstract: OBJECTIVE
  The aim of the present study was to determine the predictive value of olfactory dysfunction for the early development of a synuclein-mediated neurodegenerative disease in subjects with idiopathic REM sleep behavior disorder (iRBD) over an observational period of 5 years.
  
  
  METHODS
  Thirty-four patients with polysomnography-confirmed iRBD underwent olfactory testing using the entire Sniffin' Sticks test assessing odor identification, odor discrimination, and olfactory threshold. Patients with iRBD were prospectively followed up over a period of 4.9 ± 0.3 years (mean ± SD). The diagnosis of neurodegenerative diseases was based on current clinical diagnostic criteria.
  
  
  RESULTS
  After 2.4 ± 1.7 years (mean ± SD), 9 patients (26.5%) with iRBD developed a Lewy body disease (6 Parkinson disease and 3 dementia with Lewy bodies). The entire Sniffin' Sticks test and the identification subtest had the same overall diagnostic accuracy of 82.4% (95% confidence interval: 66.1%-92.0%) in predicting conversion. The relative risk for a Lewy body disease in the lowest tertile of olfactory function was 7.3 (95% confidence interval: 1.8-29.6) compared with the top 2 tertiles.
  
  
  CONCLUSIONS
  Assessment of olfactory function, particularly odor identification, may help to predict the development of a Lewy body disease in patients with iRBD over a relatively short time period and thus to identify patients suitable for future disease modification trials.
authors.affiliation: From the Department of Neurology (P.M., B.H., B.F., C.M., T.M., V.G., F.B., C.S., W.P., K.S.), Medical University Innsbruck; Department of Medical Statistics, Informatics and Health Economics (G.G.), Medical University Innsbruck, Austria; Neurology Service (A.I., J.S., E.T., M.S.), Hospital Clinic, Barcelona; Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CIBERNED) (A.I., J.S., E.T., M.S.); and IDIBAPS (A.I., J.S., E.T., M.S.), Barcelona, Spain.
authors.forename: Philipp
authors.initials: P
authors.lastname: Mahlknecht
authors.affiliation: From the Department of Neurology (P.M., B.H., B.F., C.M., T.M., V.G., F.B., C.S., W.P., K.S.), Medical University Innsbruck; Department of Medical Statistics, Informatics and Health Economics (G.G.), Medical University Innsbruck, Austria; Neurology Service (A.I., J.S., E.T., M.S.), Hospital Clinic, Barcelona; Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CIBERNED) (A.I., J.S., E.T., M.S.); and IDIBAPS (A.I., J.S., E.T., M.S.), Barcelona, Spain. klaus.seppi@uki.at airanzo@clinic.ub.es.
authors.forename: Alex
authors.initials: A
authors.lastname: Iranzo
authors.affiliation: From the Department of Neurology (P.M., B.H., B.F., C.M., T.M., V.G., F.B., C.S., W.P., K.S.), Medical University Innsbruck; Department of Medical Statistics, Informatics and Health Economics (G.G.), Medical University Innsbruck, Austria; Neurology Service (A.I., J.S., E.T., M.S.), Hospital Clinic, Barcelona; Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CIBERNED) (A.I., J.S., E.T., M.S.); and IDIBAPS (A.I., J.S., E.T., M.S.), Barcelona, Spain.
authors.forename: Birgit
authors.initials: B
authors.lastname: Högl
authors.affiliation: From the Department of Neurology (P.M., B.H., B.F., C.M., T.M., V.G., F.B., C.S., W.P., K.S.), Medical University Innsbruck; Department of Medical Statistics, Informatics and Health Economics (G.G.), Medical University Innsbruck, Austria; Neurology Service (A.I., J.S., E.T., M.S.), Hospital Clinic, Barcelona; Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CIBERNED) (A.I., J.S., E.T., M.S.); and IDIBAPS (A.I., J.S., E.T., M.S.), Barcelona, Spain.
authors.forename: Birgit
authors.initials: B
authors.lastname: Frauscher
authors.affiliation: From the Department of Neurology (P.M., B.H., B.F., C.M., T.M., V.G., F.B., C.S., W.P., K.S.), Medical University Innsbruck; Department of Medical Statistics, Informatics and Health Economics (G.G.), Medical University Innsbruck, Austria; Neurology Service (A.I., J.S., E.T., M.S.), Hospital Clinic, Barcelona; Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CIBERNED) (A.I., J.S., E.T., M.S.); and IDIBAPS (A.I., J.S., E.T., M.S.), Barcelona, Spain.
authors.forename: Christoph
authors.initials: C
authors.lastname: Müller
authors.affiliation: From the Department of Neurology (P.M., B.H., B.F., C.M., T.M., V.G., F.B., C.S., W.P., K.S.), Medical University Innsbruck; Department of Medical Statistics, Informatics and Health Economics (G.G.), Medical University Innsbruck, Austria; Neurology Service (A.I., J.S., E.T., M.S.), Hospital Clinic, Barcelona; Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CIBERNED) (A.I., J.S., E.T., M.S.); and IDIBAPS (A.I., J.S., E.T., M.S.), Barcelona, Spain.
authors.forename: Joan
authors.initials: J
authors.lastname: Santamaría
authors.affiliation: From the Department of Neurology (P.M., B.H., B.F., C.M., T.M., V.G., F.B., C.S., W.P., K.S.), Medical University Innsbruck; Department of Medical Statistics, Informatics and Health Economics (G.G.), Medical University Innsbruck, Austria; Neurology Service (A.I., J.S., E.T., M.S.), Hospital Clinic, Barcelona; Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CIBERNED) (A.I., J.S., E.T., M.S.); and IDIBAPS (A.I., J.S., E.T., M.S.), Barcelona, Spain.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Tolosa
authors.affiliation: From the Department of Neurology (P.M., B.H., B.F., C.M., T.M., V.G., F.B., C.S., W.P., K.S.), Medical University Innsbruck; Department of Medical Statistics, Informatics and Health Economics (G.G.), Medical University Innsbruck, Austria; Neurology Service (A.I., J.S., E.T., M.S.), Hospital Clinic, Barcelona; Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CIBERNED) (A.I., J.S., E.T., M.S.); and IDIBAPS (A.I., J.S., E.T., M.S.), Barcelona, Spain.
authors.forename: Monica
authors.initials: M
authors.lastname: Serradell
authors.affiliation: From the Department of Neurology (P.M., B.H., B.F., C.M., T.M., V.G., F.B., C.S., W.P., K.S.), Medical University Innsbruck; Department of Medical Statistics, Informatics and Health Economics (G.G.), Medical University Innsbruck, Austria; Neurology Service (A.I., J.S., E.T., M.S.), Hospital Clinic, Barcelona; Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CIBERNED) (A.I., J.S., E.T., M.S.); and IDIBAPS (A.I., J.S., E.T., M.S.), Barcelona, Spain.
authors.forename: Thomas
authors.initials: T
authors.lastname: Mitterling
authors.affiliation: From the Department of Neurology (P.M., B.H., B.F., C.M., T.M., V.G., F.B., C.S., W.P., K.S.), Medical University Innsbruck; Department of Medical Statistics, Informatics and Health Economics (G.G.), Medical University Innsbruck, Austria; Neurology Service (A.I., J.S., E.T., M.S.), Hospital Clinic, Barcelona; Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CIBERNED) (A.I., J.S., E.T., M.S.); and IDIBAPS (A.I., J.S., E.T., M.S.), Barcelona, Spain.
authors.forename: Viola
authors.initials: V
authors.lastname: Gschliesser
authors.affiliation: From the Department of Neurology (P.M., B.H., B.F., C.M., T.M., V.G., F.B., C.S., W.P., K.S.), Medical University Innsbruck; Department of Medical Statistics, Informatics and Health Economics (G.G.), Medical University Innsbruck, Austria; Neurology Service (A.I., J.S., E.T., M.S.), Hospital Clinic, Barcelona; Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CIBERNED) (A.I., J.S., E.T., M.S.); and IDIBAPS (A.I., J.S., E.T., M.S.), Barcelona, Spain.
authors.forename: Georg
authors.initials: G
authors.lastname: Goebel
authors.affiliation: From the Department of Neurology (P.M., B.H., B.F., C.M., T.M., V.G., F.B., C.S., W.P., K.S.), Medical University Innsbruck; Department of Medical Statistics, Informatics and Health Economics (G.G.), Medical University Innsbruck, Austria; Neurology Service (A.I., J.S., E.T., M.S.), Hospital Clinic, Barcelona; Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CIBERNED) (A.I., J.S., E.T., M.S.); and IDIBAPS (A.I., J.S., E.T., M.S.), Barcelona, Spain.
authors.forename: Florian
authors.initials: F
authors.lastname: Brugger
authors.affiliation: From the Department of Neurology (P.M., B.H., B.F., C.M., T.M., V.G., F.B., C.S., W.P., K.S.), Medical University Innsbruck; Department of Medical Statistics, Informatics and Health Economics (G.G.), Medical University Innsbruck, Austria; Neurology Service (A.I., J.S., E.T., M.S.), Hospital Clinic, Barcelona; Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CIBERNED) (A.I., J.S., E.T., M.S.); and IDIBAPS (A.I., J.S., E.T., M.S.), Barcelona, Spain.
authors.forename: Christoph
authors.initials: C
authors.lastname: Scherfler
authors.affiliation: From the Department of Neurology (P.M., B.H., B.F., C.M., T.M., V.G., F.B., C.S., W.P., K.S.), Medical University Innsbruck; Department of Medical Statistics, Informatics and Health Economics (G.G.), Medical University Innsbruck, Austria; Neurology Service (A.I., J.S., E.T., M.S.), Hospital Clinic, Barcelona; Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CIBERNED) (A.I., J.S., E.T., M.S.); and IDIBAPS (A.I., J.S., E.T., M.S.), Barcelona, Spain.
authors.forename: Werner
authors.initials: W
authors.lastname: Poewe
authors.affiliation: From the Department of Neurology (P.M., B.H., B.F., C.M., T.M., V.G., F.B., C.S., W.P., K.S.), Medical University Innsbruck; Department of Medical Statistics, Informatics and Health Economics (G.G.), Medical University Innsbruck, Austria; Neurology Service (A.I., J.S., E.T., M.S.), Hospital Clinic, Barcelona; Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CIBERNED) (A.I., J.S., E.T., M.S.); and IDIBAPS (A.I., J.S., E.T., M.S.), Barcelona, Spain. klaus.seppi@uki.at airanzo@clinic.ub.es.
authors.forename: Klaus
authors.initials: K
authors.lastname: Seppi
mesh_terms: D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D020961:Lewy Body Disease / Q000175:diagnosis* / Q000503:physiopathology*; D008297:Male; D009812:Odorants; D000857:Olfaction Disorders / Q000175:diagnosis / Q000503:physiopathology*; D010812:Physical Stimulation / Q000379:methods; D017286:Polysomnography; D011379:Prognosis; D020187:REM Sleep Behavior Disorder / Q000175:diagnosis / Q000503:physiopathology*