Philipp Mahlknecht1, Alex Iranzo2, Birgit Högl1, Birgit Frauscher1, Christoph Müller1, Joan Santamaría1, Eduardo Tolosa1, Monica Serradell1, Thomas Mitterling1, Viola Gschliesser1, Georg Goebel1, Florian Brugger1, Christoph Scherfler1, Werner Poewe1, Klaus Seppi2. 1. 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. 2. 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.
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.
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: Elmar H Pinkhardt; Huijing Liu; Di Ma; Jing Chen; Adrian Pachollek; Martin S Kunz; Jan Kassubek; Albert C Ludolph; Yining Huang; Haibo Chen; G Bernhard Landwehrmeyer; Zhaoxia Wang; Wen Su Journal: PLoS One Date: 2019-11-08 Impact factor: 3.240
Authors: Horacio Kaufmann; Lucy Norcliffe-Kaufmann; Jose-Alberto Palma; Italo Biaggioni; Phillip A Low; Wolfgang Singer; David S Goldstein; Amanda C Peltier; Cyndia A Shibao; Christopher H Gibbons; Roy Freeman; David Robertson Journal: Ann Neurol Date: 2017-02 Impact factor: 10.422