{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,26]],"date-time":"2026-08-26T23:48:09Z","timestamp":1787788089327,"version":"build-2784847793"},"reference-count":40,"publisher":"Public Library of Science (PLoS)","issue":"2","license":[{"start":{"date-parts":[[2021,2,19]],"date-time":"2021-02-19T00:00:00Z","timestamp":1613692800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"abstract":"<jats:sec id=\"sec001\">\n<jats:title>Background<\/jats:title>\n<jats:p>Rapid eye movement sleep behavior disorder (RBD) and olfactory dysfunction are useful for early diagnosis of Parkinson\u2019s disease (PD). RBD and severe olfactory dysfunction are also regarded as risk factors for cognitive impairment in PD. This study aimed to assess the associations between RBD, olfactory function, and clinical symptoms in patients with PD.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec002\">\n<jats:title>Methods<\/jats:title>\n<jats:p>The participants were 404 patients with non-demented PD. Probable RBD (pRBD) was determined using the Japanese version of the RBD screening questionnaire (RBDSQ-J) and the RBD Single-Question Screen (RBD1Q). Olfactory function was evaluated using the odor identification test for Japanese. Clinical symptoms were evaluated using the Movement Disorder Society Revision of the Unified PD Rating Scale (MDS-UPDRS) parts I\u2013IV.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec003\">\n<jats:title>Results<\/jats:title>\n<jats:p>In total, 134 (33.2%) patients indicated a history of pRBD as determined by the RBD1Q and 136 (33.7%) by the RBDSQ-J based on a cutoff value of 6 points. Moreover, 101 patients were diagnosed as pRBD by both questionnaires, 35 by the RBDSQ-J only, and 33 by the RBD1Q only. The MDS-UPDRS parts I\u2013III scores were significantly higher and disease duration significantly longer in the pRBD group. pRBD was significantly associated with male gender and the MDS-UPDRS part I score. The olfactory identification function was significantly reduced in the pRBD group.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec004\">\n<jats:title>Conclusions<\/jats:title>\n<jats:p>About 33% of the patients with PD had pRBD based on the questionnaires, and both motor and non-motor functions were significantly decreased in these patients. These results suggest that more extensive degeneration occurred in patients with non-demented PD with RBD.<\/jats:p>\n<\/jats:sec>","DOI":"10.1371\/journal.pone.0247443","type":"journal-article","created":{"date-parts":[[2021,2,20]],"date-time":"2021-02-20T03:22:41Z","timestamp":1613791361000},"page":"e0247443","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":20,"title":["Associations between probable REM sleep behavior disorder, olfactory disturbance, and clinical symptoms in Parkinson\u2019s disease: A multicenter cross-sectional study"],"prefix":"10.1371","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7384-0930","authenticated-orcid":true,"given":"Mutsumi","family":"Iijima","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yasuyuki","family":"Okuma","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Keisuke","family":"Suzuki","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fumihito","family":"Yoshii","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shigeru","family":"Nogawa","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Takashi","family":"Osada","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Koichi","family":"Hirata","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kazuo","family":"Kitagawa","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nobutaka","family":"Hattori","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2021,2,19]]},"reference":[{"key":"pone.0247443.ref001","doi-asserted-by":"crossref","first-page":"293","DOI":"10.1093\/sleep\/9.2.293","article-title":"Chronic behavioral disorders of human REM sleep: a new category of parasomnia","volume":"9","author":"CH Schenck","year":"1986","journal-title":"Sleep"},{"key":"pone.0247443.ref002","doi-asserted-by":"crossref","first-page":"424","DOI":"10.1016\/S1474-4422(06)70441-0","article-title":"Rapid-eye-movementsleep behaviour disorder and neurodegenerative diseases","volume":"5","author":"JF Gagnon","year":"2006","journal-title":"Lancet Neurol"},{"key":"pone.0247443.ref003","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1111\/j.1749-6632.2009.05115.x","article-title":"REM sleep behavior disorder: Updated review of the core features, the REM sleep behavior disorder-neurodegenerative disease association, evolving concepts, controversies, and future directions","volume":"1184","author":"BF Boeve","year":"2010","journal-title":"Ann NY Acad Sci"},{"key":"pone.0247443.ref004","doi-asserted-by":"crossref","first-page":"634","DOI":"10.1002\/mds.27018","article-title":"REM sleep behavior disorder in Parkinson\u2019s disease and other synucleinopathies","volume":"32","author":"EK St Louis","year":"2017","journal-title":"Mov Disord"},{"key":"pone.0247443.ref005","doi-asserted-by":"crossref","first-page":"585","DOI":"10.1212\/WNL.59.4.585","article-title":"REM sleep behavior disorder and REM sleep without atonia in Parkinson\u2019s disease","volume":"59","author":"JF Gagnon","year":"2002","journal-title":"Neurology"},{"key":"pone.0247443.ref006","doi-asserted-by":"crossref","first-page":"164","DOI":"10.1159\/000189269","article-title":"Parkinson\u2019s disease with and without REM sleep behaviour disorder: Are there any clinical differences?","volume":"61","author":"A Yoritaka","year":"2009","journal-title":"Eur Neurol"},{"issue":"5","key":"pone.0247443.ref007","first-page":"60","article-title":"Symptoms of rapid eye movement sleep behavior disorder are associated with cholinergic denervation in Parkinson disease","volume":"71","author":"V Kotagal","year":"2012","journal-title":"Ann Neurol"},{"key":"pone.0247443.ref008","doi-asserted-by":"crossref","first-page":"1606","DOI":"10.1007\/s00415-011-6386-1","article-title":"REM sleep behavior disorder in Japanese patients with Parkinson\u2019s disease: a multicenter study using the REM sleep behavior disorder screening questionnaire","volume":"259","author":"Y Nihei","year":"2012","journal-title":"J Neurol"},{"key":"pone.0247443.ref009","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1016\/j.sleep.2012.10.011","article-title":"Clinical significance of REM sleep behavior disorder in Parkinson\u2019s disease","volume":"14","author":"T Nomura","year":"2013","journal-title":"Sleep Medicine"},{"key":"pone.0247443.ref010","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1186\/1471-2377-13-18","article-title":"Probable rapid eye movement sleep behavior disorder, nocturnal disturbances and quality of life in patients with Parkinson\u2019s disease: a case-controlled study using the rapid eye movement sleep behavior disorder screening questionnaire","volume":"13","author":"K Suzuki","year":"2013","journal-title":"BMC Neurol"},{"key":"pone.0247443.ref011","doi-asserted-by":"crossref","first-page":"953","DOI":"10.1136\/jnnp-2017-316136","article-title":"Impact of sleep-related symptoms on clinical motor subtypes and disability in Parkinson\u2019s disease: a multicenter cross-sectional study","volume":"88","author":"K Suzuki","year":"2017","journal-title":"J Neurol Neurosurg Psychiatry"},{"key":"pone.0247443.ref012","doi-asserted-by":"crossref","first-page":"865","DOI":"10.1002\/mds.26989","article-title":"Validation of the MDS research criteria for prodromal Parkinson\u2019s disease: Longitudinal assessment in a REM sleep behavior disorder (RBD) cohort","volume":"32","author":"SM Fereshtehnejad","year":"2017","journal-title":"Mov Disord"},{"key":"pone.0247443.ref013","doi-asserted-by":"crossref","first-page":"62","DOI":"10.1016\/j.parkreldis.2018.03.021","article-title":"Investigation of non-motor symptoms in first-degree relatives of patients with Parkinson\u2019s disease","volume":"52","author":"J Liu","year":"2018","journal-title":"Parkinsonism Relat Disord"},{"key":"pone.0247443.ref014","doi-asserted-by":"crossref","first-page":"1288","DOI":"10.1136\/jnnp-2018-318275","article-title":"Non-motor features of Parkinson\u2019s disease in a nested case\u2013control study of US men","volume":"89","author":"KC Hughes","year":"2018","journal-title":"J Neurol Neurosurg Psychiatry"},{"key":"pone.0247443.ref015","doi-asserted-by":"crossref","first-page":"126","DOI":"10.1093\/brain\/awh322","article-title":"Combination of \u2018idiopathic\u2019 REM sleep behaviour disorder and olfactory dysfunction as possible indicator for \u03b1-synucleinopathy demonstrated by dopamine transporter FP-CIT-SPECT","volume":"128","author":"K Stiasny-Kolster","year":"2005","journal-title":"Brain"},{"key":"pone.0247443.ref016","doi-asserted-by":"crossref","first-page":"e89741","DOI":"10.1371\/journal.pone.0089741","article-title":"Neurodegenerative disorder risk in idiopathic REM sleep behavior disorder: study in 174 patients","volume":"9","author":"A Iranzo","year":"2014","journal-title":"PloS One"},{"key":"pone.0247443.ref017","doi-asserted-by":"crossref","first-page":"654","DOI":"10.1212\/WNL.0000000000001265","article-title":"Olfactory dysfunction predicts early transition to a Lewy body disease in idiopathic RBD","volume":"84","author":"Sleep Innsbruck Barcelona Group","year":"2015","journal-title":"Neurology"},{"key":"pone.0247443.ref018","doi-asserted-by":"crossref","first-page":"744","DOI":"10.1093\/brain\/awz030","article-title":"Risk and predictors of dementia and parkinsonism in idiopathic REM sleep behavior disorder: a multicentre study","volume":"142","author":"RB Postuma","year":"2019","journal-title":"Brain"},{"key":"pone.0247443.ref019","doi-asserted-by":"crossref","first-page":"e894","DOI":"10.1212\/WNL.0000000000006134","article-title":"REM behavior disorder predicts motor progression and cognitive decline in Parkinson disease","volume":"91","author":"G Pagano","year":"2018","journal-title":"Neurology"},{"key":"pone.0247443.ref020","doi-asserted-by":"crossref","first-page":"35","DOI":"10.1186\/s40035-017-0105-5","article-title":"Clinical features of Parkinson\u2019s disease with and without rapid eye movement sleep behavior disorder","volume":"6","author":"Y Liu","year":"2017","journal-title":"Transl. Neurodegener"},{"key":"pone.0247443.ref021","doi-asserted-by":"crossref","first-page":"331","DOI":"10.1038\/nrneurol.2009.62","article-title":"Hallucinations in Parkinson disease","volume":"5","author":"NJ Diederich","year":"2009","journal-title":"Nat Rev Neurol"},{"key":"pone.0247443.ref022","doi-asserted-by":"crossref","first-page":"560","DOI":"10.1136\/jnnp-2013-306104","article-title":"REM sleep behaviour disorder is associated with worse quality of life and other non-motor features in early Parkinson\u2019s disease","volume":"85","author":"M Rolinski","year":"2014","journal-title":"J Neurol Neurosurg Psychiatry"},{"key":"pone.0247443.ref023","doi-asserted-by":"crossref","first-page":"1035","DOI":"10.1016\/j.sleep.2013.04.018","article-title":"Rapid eye movement sleep behavior disorder in treatment-na\u00efve Parkinson disease patients","volume":"14","author":"L Plomhause","year":"2013","journal-title":"Sleep Medicine"},{"key":"pone.0247443.ref024","doi-asserted-by":"crossref","first-page":"2386","DOI":"10.1002\/mds.21740","article-title":"The REM sleep behavior disorder screening questionnaire\u2013a new diagnostic instrument","volume":"22","author":"K Stiasny-Kolster","year":"2007","journal-title":"Mov Disord"},{"key":"pone.0247443.ref025","doi-asserted-by":"crossref","first-page":"1151","DOI":"10.1016\/j.sleep.2009.05.007","article-title":"The REM sleep behavior disorder screening questionnaire:Validation study of a Japanese version","volume":"10","author":"T Miyamoto","year":"2009","journal-title":"Sleep Medicine"},{"key":"pone.0247443.ref026","doi-asserted-by":"crossref","first-page":"711","DOI":"10.1016\/j.sleep.2011.01.015","article-title":"Utility of the REM sleep behavior disorder screening questionnaire (RBDSQ) in Parkinson\u2019s disease patients","volume":"12","author":"T Nomura","year":"2011","journal-title":"Sleep Medicine"},{"key":"pone.0247443.ref027","doi-asserted-by":"crossref","first-page":"913","DOI":"10.1002\/mds.25037","article-title":"A Single-Question Screen for REM Sleep Behavior Disorder: A Multicenter Validation Study","volume":"27","author":"RB Postuma","year":"2012","journal-title":"Mov Disord"},{"key":"pone.0247443.ref028","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1093\/sleep\/zsz323","article-title":"Diagnosing REM sleep behavior disorder in Parkinson\u2019s disease without a gold standard: a latent-class model study","volume":"43","author":"M Figorilli","year":"2020","journal-title":"Sleep"},{"key":"pone.0247443.ref029","doi-asserted-by":"crossref","first-page":"181","DOI":"10.1136\/jnnp.55.3.181","article-title":"Accuracy of clinical diagnosis of idiopathic Parkinson\u2019s disease: a clinico-pathological study of 100 cases","volume":"55","author":"AJ Hughes","year":"1992","journal-title":"J Neurol Neurosurg Psychiatry"},{"key":"pone.0247443.ref030","doi-asserted-by":"crossref","first-page":"200","DOI":"10.1002\/mdc3.12058","article-title":"Official Japanese Version of the Movement Disorder Society-Unified Parkinson\u2019s Disease Rating Scale: validation against the original English version","volume":"1","author":"K Kashihara","year":"2014","journal-title":"Mov Disord Clin Pract"},{"key":"pone.0247443.ref031","doi-asserted-by":"crossref","first-page":"1887","DOI":"10.2169\/internalmedicine.47.1345","article-title":"Smell identification in Japanese Parkinson\u2019s disease patients: using the odor stick identification test for Japanese subjects","volume":"47","author":"M Iijima","year":"2008","journal-title":"Intern Med"},{"key":"pone.0247443.ref032","doi-asserted-by":"crossref","first-page":"1039","DOI":"10.1007\/s10072-017-2886-9","article-title":"Diagnostic accuracy of REM sleep behavour disorder screening questionnaire: a meta-analysis","volume":"38","author":"K Li","year":"2017","journal-title":"Neurol Sci"},{"key":"pone.0247443.ref033","doi-asserted-by":"crossref","first-page":"171","DOI":"10.1002\/mdc3.12591","article-title":"The REM sleep behavior disorder screening questionnaire is not valid in de novo Parkinson\u2019s disease","volume":"5","author":"C Halsband","year":"2018","journal-title":"Mov Disord Clin Prac"},{"key":"pone.0247443.ref034","doi-asserted-by":"crossref","first-page":"194","DOI":"10.1016\/j.jns.2019.02.028","article-title":"Apathy in Parkinson\u2019s disease with REM sleep behavior disorder","volume":"399","author":"P Bargiotas","year":"2019","journal-title":"J Neurol Sci"},{"key":"pone.0247443.ref035","doi-asserted-by":"crossref","first-page":"26782","DOI":"10.1038\/srep26782","article-title":"Structural brain alterations associated with rapid eye movement sleep behavior disorder in Parkinson\u2019s disease","volume":"6","author":"S Boucetta","year":"2016","journal-title":"Sci Rep"},{"key":"pone.0247443.ref036","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1093\/sleep\/zsz062","article-title":"Brain atrophy in Parkinson\u2019s disease with polysomnography-confirmed REM sleep behavior disorder","volume":"42","author":"S Rahayel","year":"2019","journal-title":"Sleep"},{"key":"pone.0247443.ref037","doi-asserted-by":"crossref","first-page":"1162","DOI":"10.1097\/NEN.0000000000000014","article-title":"Pedunculopontine cholinergic cell loss in hallucinating Parkinson disease patients but not in dementia with Lewy bodies patients","volume":"72","author":"DH Hepp","year":"2013","journal-title":"J Neuropathol Exp Neurol"},{"key":"pone.0247443.ref038","doi-asserted-by":"crossref","first-page":"96","DOI":"10.1016\/j.cortex.2015.10.015","article-title":"Altered functional connectivity in lesional peduncular hallucinosis with REM sleep behavior disorder","volume":"74","author":"MR Geddes","year":"2016","journal-title":"Cortex"},{"key":"pone.0247443.ref039","doi-asserted-by":"crossref","first-page":"527","DOI":"10.1016\/j.nbd.2011.10.026","article-title":"Olfaction in Parkinson\u2019s disease and related disorders","volume":"46","author":"RL Doty","year":"2012","journal-title":"Neurobiol Dis"},{"key":"pone.0247443.ref040","doi-asserted-by":"crossref","first-page":"161","DOI":"10.1093\/brain\/awr321","article-title":"Severe olfactory dysfunction is a prodromal symptom of dementia associated with Parkinson\u2019s disease: a 3 year longitudinal study","volume":"135","author":"T Baba","year":"2012","journal-title":"Brain"}],"container-title":["PLOS ONE"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0247443","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,2,20]],"date-time":"2021-02-20T03:23:12Z","timestamp":1613791392000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0247443"}},"subtitle":[],"editor":[{"given":"Mathias","family":"Toft","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2021,2,19]]},"references-count":40,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2021,2,19]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0247443","relation":{},"ISSN":["1932-6203"],"issn-type":[{"value":"1932-6203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,2,19]]}}}