{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,15]],"date-time":"2026-05-15T22:57:44Z","timestamp":1778885864491,"version":"3.51.4"},"reference-count":34,"publisher":"Springer Science and Business Media LLC","issue":"2","license":[{"start":{"date-parts":[[2024,9,26]],"date-time":"2024-09-26T00:00:00Z","timestamp":1727308800000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2024,9,26]],"date-time":"2024-09-26T00:00:00Z","timestamp":1727308800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"funder":[{"DOI":"10.13039\/501100006407","name":"Natural Science Foundation of Henan Province","doi-asserted-by":"publisher","award":["232300420061"],"award-info":[{"award-number":["232300420061"]}],"id":[{"id":"10.13039\/501100006407","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Joint Construction Project of Medical Science and Technology Research Plan of Henan Province","award":["LHGJ20230549"],"award-info":[{"award-number":["LHGJ20230549"]}]},{"name":"Joint Construction Project of Medical Science and Technology Research Plan of Henan Province","award":["LHGJ20210548"],"award-info":[{"award-number":["LHGJ20210548"]}]},{"name":"National Foreign Expert Project","award":["G2023026014L"],"award-info":[{"award-number":["G2023026014L"]}]},{"name":"Research Innovation Support Program for Graduate Students of Xinxiang Medical University","award":["YJSCX2022114Y"],"award-info":[{"award-number":["YJSCX2022114Y"]}]}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Neurol Sci"],"published-print":{"date-parts":[[2025,2]]},"abstract":"<jats:title>Abstract<\/jats:title>\n          <jats:sec>\n            <jats:title>Background<\/jats:title>\n            <jats:p>Excessive daytime sleepiness (EDS) and freezing of gait (FOG) are prevalent non-motor and motor symptoms in patients with Parkinson\u2019s disease (PD), significantly impacting their quality of life. However, the correlation between EDS and FOG progression in\u00a0<jats:italic>de novo<\/jats:italic>\u00a0PD patients remains controversial.<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Methods<\/jats:title>\n            <jats:p>A total of 328 participants from the Parkinson\u2019s Progression Markers Initiative (PPMI) were divided into two groups: 43 with EDS (EDS group) and 285 without EDS (nEDS group). The cumulative incidence of FOG was assessed at the 5-year follow-up using Kaplan\u2013Meier and log-rank tests. Multivariate Cox proportional hazards models were used to assess the impact of EDS on FOG progression in PD patients, with validation for robustness through sensitivity and subgroup analyses.<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Results<\/jats:title>\n            <jats:p>The EDS group experienced a higher incidence of FOG throughout the 5-year follow-up than did the nEDS group. Multivariate Cox proportional hazards models showed significantly association between EDS severity and enhanced risk of developing FOG (HR\u2009=\u20091.076, 95% CI:1.007\u2009~\u20091.149, <jats:italic>P<\/jats:italic>\u2009=\u20090.031). For sensitivity analysis, parallel analyses\u00a0were performed\u00a0by substituting the independent variable with categorical variables, which yielded analogous outcomes (HR\u2009=\u20091.837, 95% CI:1.063\u2009~\u20093.174,\u00a0<jats:italic>P<\/jats:italic>\u2009=\u20090.029). Furthermore, subgroup analyses based on sex, age, TD\/PIGD classification, depressive symptoms, cognitive impairment, mean caudate nucleus uptake level, mean putamen nucleus uptake level and CSF A\u03b2-42 level revealed no significant interactions between subgroups (all\u00a0<jats:italic>P<\/jats:italic>\u00a0values for interaction were\u2009&gt;\u20090.05).<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Conclusion<\/jats:title>\n            <jats:p>EDS is a potential prognosis factor for the progression of FOG in patients with PD.<\/jats:p>\n          <\/jats:sec>","DOI":"10.1007\/s10072-024-07738-8","type":"journal-article","created":{"date-parts":[[2024,9,26]],"date-time":"2024-09-26T08:02:04Z","timestamp":1727337724000},"page":"723-731","update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Impact of excessive daytime sleepiness on the progression of freezing of gait in de novo Parkinson\u2019s disease: a cohort study"],"prefix":"10.1007","volume":"46","author":[{"given":"Min","family":"Chen","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yanjie","family":"Guo","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xuewei","family":"Zhang","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Maoyun","family":"Zhao","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tinghua","family":"Zheng","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jingyang","family":"Song","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Feng-Tao","family":"Liu","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2096-7249","authenticated-orcid":false,"given":"Hongxia","family":"Xing","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"297","published-online":{"date-parts":[[2024,9,26]]},"reference":[{"key":"7738_CR1","doi-asserted-by":"publisher","first-page":"734","DOI":"10.1016\/S1474-4422(11)70143-0","volume":"10","author":"JG Nutt","year":"2011","unstructured":"Nutt JG, Bloem BR, Giladi N et al (2011) Freezing of gait: moving forward on a mysterious clinical phenomenon. Lancet Neurol 10:734\u2013744. https:\/\/doi.org\/10.1016\/S1474-4422(11)70143-0","journal-title":"Lancet Neurol"},{"key":"7738_CR2","doi-asserted-by":"publisher","first-page":"153","DOI":"10.1007\/s13760-019-01217-0","volume":"121","author":"T Akt\u00fcrk","year":"2021","unstructured":"Akt\u00fcrk T, G\u00fcven H, G\u00fcven B, \u00c7omo\u011flu S (2021) Association of freezing of gait and clinical features in patients with Parkinson\u2019s disease. Acta Neurol Belg 121:153\u2013159. https:\/\/doi.org\/10.1007\/s13760-019-01217-0","journal-title":"Acta Neurol Belg"},{"key":"7738_CR3","doi-asserted-by":"publisher","first-page":"1712","DOI":"10.1212\/WNL.56.12.1712","volume":"56","author":"N Giladi","year":"2001","unstructured":"Giladi N, McDermott MP, Fahn S et al (2001) Freezing of gait in PD: Prospective assessment in the DATATOP cohort. Neurology 56:1712\u20131721. https:\/\/doi.org\/10.1212\/WNL.56.12.1712","journal-title":"Neurology"},{"key":"7738_CR4","doi-asserted-by":"publisher","first-page":"884","DOI":"10.1001\/jamaneurol.2014.753","volume":"71","author":"S Perez-Lloret","year":"2014","unstructured":"Perez-Lloret S, Negre-Pages L, Damier P et al (2014) Prevalence, determinants, and effect on quality of life of freezing of gait in Parkinson disease. JAMA Neurol 71:884. https:\/\/doi.org\/10.1001\/jamaneurol.2014.753","journal-title":"JAMA Neurol"},{"key":"7738_CR5","doi-asserted-by":"publisher","first-page":"12","DOI":"10.1186\/s40035-020-00191-5","volume":"9","author":"C Gao","year":"2020","unstructured":"Gao C, Liu J, Tan Y, Chen S (2020) Freezing of gait in Parkinson\u2019s disease: pathophysiology, risk factors and treatments. Transl Neurodegener 9:12. https:\/\/doi.org\/10.1186\/s40035-020-00191-5","journal-title":"Transl Neurodegener"},{"key":"7738_CR6","doi-asserted-by":"publisher","first-page":"121","DOI":"10.3389\/fneur.2019.00121","volume":"10","author":"Y Xiang","year":"2019","unstructured":"Xiang Y, Xu Q, Sun Q et al (2019) Clinical features and correlates of excessive daytime sleepiness in Parkinson\u2019s disease. Front Neurol 10:121. https:\/\/doi.org\/10.3389\/fneur.2019.00121","journal-title":"Front Neurol"},{"key":"7738_CR7","doi-asserted-by":"publisher","first-page":"149","DOI":"10.1007\/s10072-023-06974-8","volume":"45","author":"E Naghavi","year":"2024","unstructured":"Naghavi E, Aliasin MM (2024) Epworth sleepiness scale is associated with increased striatal dopamine uptake in Parkinson\u2019s disease: a cross-sectional study. Neurol Sci 45:149\u2013154. https:\/\/doi.org\/10.1007\/s10072-023-06974-8","journal-title":"Neurol Sci"},{"key":"7738_CR8","doi-asserted-by":"publisher","first-page":"311","DOI":"10.1016\/j.gaitpost.2018.12.009","volume":"68","author":"SJ Banks","year":"2019","unstructured":"Banks SJ, Bayram E, Shan G et al (2019) Non-motor predictors of freezing of gait in Parkinson\u2019s disease. Gait Posture 68:311\u2013316. https:\/\/doi.org\/10.1016\/j.gaitpost.2018.12.009","journal-title":"Gait Posture"},{"key":"7738_CR9","doi-asserted-by":"publisher","first-page":"e40","DOI":"10.1212\/WNL.0000000000006692","volume":"92","author":"R Kim","year":"2019","unstructured":"Kim R, Lee J, Kim H-J et al (2019) CSF \u03b2-amyloid42 and risk of freezing of gait in early Parkinson disease. Neurology 92:e40\u2013e47. https:\/\/doi.org\/10.1212\/WNL.0000000000006692","journal-title":"Neurology"},{"key":"7738_CR10","doi-asserted-by":"publisher","first-page":"6452","DOI":"10.1007\/s00415-022-11294-6","volume":"269","author":"L Lv","year":"2022","unstructured":"Lv L, Zhang H, Tan X et al (2022) Associated factors and abnormal dorsal raphe nucleus connectivity patterns of freezing of gait in Parkinson\u2019s disease. J Neurol 269:6452\u20136466","journal-title":"J Neurol"},{"key":"7738_CR11","doi-asserted-by":"publisher","DOI":"10.1002\/brb3.1244","volume":"9","author":"M Sawada","year":"2019","unstructured":"Sawada M, Wada-Isoe K, Hanajima R, Nakashima K (2019) Clinical features of freezing of gait in Parkinson\u2019s disease patients. Brain Behav 9:e01244. https:\/\/doi.org\/10.1002\/brb3.1244","journal-title":"Brain Behav"},{"key":"7738_CR12","doi-asserted-by":"publisher","first-page":"779","DOI":"10.5664\/jcsm.9022","volume":"17","author":"X Tang","year":"2021","unstructured":"Tang X, Yu L, Yang J et al (2021) Association of sleep disturbance and freezing of gait in Parkinson disease: prevention\/delay implications. J Clin Sleep Med JCSM Off Publ Am Acad Sleep Med 17:779\u2013789. https:\/\/doi.org\/10.5664\/jcsm.9022","journal-title":"J Clin Sleep Med JCSM Off Publ Am Acad Sleep Med"},{"key":"7738_CR13","doi-asserted-by":"publisher","DOI":"10.1002\/brb3.931","volume":"8","author":"R Ou","year":"2018","unstructured":"Ou R, Wei Q, Cao B et al (2018) Predictors of freezing of gait in Chinese patients with Parkinson\u2019s disease. Brain Behav 8:e00931. https:\/\/doi.org\/10.1002\/brb3.931","journal-title":"Brain Behav"},{"key":"7738_CR14","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0269227","volume":"17","author":"RD Landes","year":"2022","unstructured":"Landes RD, Glover A, Pillai L et al (2022) Levodopa ONOFF-state freezing of gait: Defining the gait and non-motor phenotype. PLoS ONE 17:e0269227. https:\/\/doi.org\/10.1371\/journal.pone.0269227","journal-title":"PLoS ONE"},{"key":"7738_CR15","doi-asserted-by":"publisher","first-page":"1030","DOI":"10.1212\/WNL.0b013e3182a4a408","volume":"81","author":"A Videnovic","year":"2013","unstructured":"Videnovic A, Marlin C, Alibiglou L et al (2013) Increased REM sleep without atonia in Parkinson disease with freezing of gait. Neurology 81:1030\u20131035. https:\/\/doi.org\/10.1212\/WNL.0b013e3182a4a408","journal-title":"Neurology"},{"key":"7738_CR16","doi-asserted-by":"publisher","first-page":"629","DOI":"10.1016\/j.pneurobio.2011.09.005","volume":"95","author":"K Marek","year":"2011","unstructured":"Marek K, Jennings D, Lasch S et al (2011) The Parkinson Progression Marker Initiative (PPMI). Biol Markers Neurodegener Dis 95:629\u2013635. https:\/\/doi.org\/10.1016\/j.pneurobio.2011.09.005","journal-title":"Biol Markers Neurodegener Dis"},{"key":"7738_CR17","doi-asserted-by":"publisher","first-page":"2129","DOI":"10.1002\/mds.22340","volume":"23","author":"CG Goetz","year":"2008","unstructured":"Goetz CG, Tilley BC, Shaftman SR et al (2008) Movement disorder society-sponsored revision of the Unified Parkinson\u2019s Disease Rating Scale (MDS-UPDRS): Scale presentation and clinimetric testing results. Mov Disord 23:2129\u20132170. https:\/\/doi.org\/10.1002\/mds.22340","journal-title":"Mov Disord"},{"key":"7738_CR18","doi-asserted-by":"publisher","first-page":"173","DOI":"10.1016\/j.parkreldis.2020.10.033","volume":"81","author":"R Kim","year":"2020","unstructured":"Kim R, Shin JH, Park S et al (2020) Apolipoprotein E \u03b54 genotype and risk of freezing of gait in Parkinson\u2019s disease. Parkinsonism Relat Disord 81:173\u2013178. https:\/\/doi.org\/10.1016\/j.parkreldis.2020.10.033","journal-title":"Parkinsonism Relat Disord"},{"key":"7738_CR19","doi-asserted-by":"publisher","first-page":"540","DOI":"10.1093\/sleep\/14.6.540","volume":"14","author":"MW Johns","year":"1991","unstructured":"Johns MW (1991) A new method for measuring daytime sleepiness: the epworth sleepiness scale. Sleep 14:540\u2013545. https:\/\/doi.org\/10.1093\/sleep\/14.6.540","journal-title":"Sleep"},{"key":"7738_CR20","doi-asserted-by":"publisher","first-page":"935","DOI":"10.1007\/s00401-016-1552-2","volume":"131","author":"J-H Kang","year":"2016","unstructured":"Kang J-H, Mollenhauer B, Coffey CS et al (2016) CSF biomarkers associated with disease heterogeneity in early Parkinson\u2019s disease: the Parkinson\u2019s Progression Markers Initiative study. Acta Neuropathol (Berl) 131:935\u2013949. https:\/\/doi.org\/10.1007\/s00401-016-1552-2","journal-title":"Acta Neuropathol (Berl)"},{"key":"7738_CR21","doi-asserted-by":"publisher","DOI":"10.1016\/j.arr.2022.101834","volume":"84","author":"ABR Leite Silva","year":"2023","unstructured":"Leite Silva ABR, Gon\u00e7alves De Oliveira RW, Di\u00f3genes GP et al (2023) Premotor, nonmotor and motor symptoms of Parkinson\u2019s Disease: A new clinical state of the art. Ageing Res Rev 84:101834. https:\/\/doi.org\/10.1016\/j.arr.2022.101834","journal-title":"Ageing Res Rev"},{"key":"7738_CR22","doi-asserted-by":"publisher","first-page":"162","DOI":"10.1212\/WNL.0000000000001737","volume":"85","author":"LK Tholfsen","year":"2015","unstructured":"Tholfsen LK, Larsen JP, Schulz J et al (2015) Development of excessive daytime sleepiness in early Parkinson disease. Neurology 85:162\u2013168. https:\/\/doi.org\/10.1212\/WNL.0000000000001737","journal-title":"Neurology"},{"key":"7738_CR23","doi-asserted-by":"publisher","first-page":"1151","DOI":"10.1007\/s10072-019-03785-8","volume":"40","author":"S-W Yoo","year":"2019","unstructured":"Yoo S-W, Kim J-S, Oh Y-S et al (2019) Excessive daytime sleepiness and its impact on quality of life in de novo Parkinson\u2019s disease. Neurol Sci 40:1151\u20131156. https:\/\/doi.org\/10.1007\/s10072-019-03785-8","journal-title":"Neurol Sci"},{"key":"7738_CR24","doi-asserted-by":"publisher","first-page":"1097251","DOI":"10.3389\/fneur.2023.1097251","volume":"14","author":"K Ogaki","year":"2023","unstructured":"Ogaki K, Fujita H, Nozawa N et al (2023) Factors contributing to sleep disturbances and excessive daytime sleepiness in patients with Parkinson\u2019s disease. Front Neurol 14:1097251. https:\/\/doi.org\/10.3389\/fneur.2023.1097251","journal-title":"Front Neurol"},{"key":"7738_CR25","doi-asserted-by":"publisher","DOI":"10.1016\/j.nbd.2023.106048","volume":"179","author":"JL McKay","year":"2023","unstructured":"McKay JL, Nye J, Goldstein FC et al (2023) Levodopa responsive freezing of gait is associated with reduced norepinephrine transporter binding in Parkinson\u2019s disease. Neurobiol Dis 179:106048. https:\/\/doi.org\/10.1016\/j.nbd.2023.106048","journal-title":"Neurobiol Dis"},{"key":"7738_CR26","doi-asserted-by":"publisher","first-page":"1442","DOI":"10.1212\/01.wnl.0000183056.89590.0d","volume":"65","author":"RD Abbott","year":"2005","unstructured":"Abbott RD, Ross GW, White LR et al (2005) Excessive daytime sleepiness and subsequent development of Parkinson disease. Neurology 65:1442\u20131446. https:\/\/doi.org\/10.1212\/01.wnl.0000183056.89590.0d","journal-title":"Neurology"},{"key":"7738_CR27","doi-asserted-by":"publisher","first-page":"1710","DOI":"10.1002\/mds.26048","volume":"29","author":"AJ Espay","year":"2014","unstructured":"Espay AJ, LeWitt PA, Kaufmann H (2014) Norepinephrine deficiency in Parkinson\u2019s disease: The case for noradrenergic enhancement. Mov Disord 29:1710\u20131719. https:\/\/doi.org\/10.1002\/mds.26048","journal-title":"Mov Disord"},{"key":"7738_CR28","doi-asserted-by":"publisher","first-page":"48","DOI":"10.1016\/j.ejphar.2012.08.016","volume":"695","author":"B Tang","year":"2012","unstructured":"Tang B, Dafny N (2012) Methylphenidate modulates the locus ceruleus neuronal activity in freely behaving rat. Eur J Pharmacol 695:48\u201356. https:\/\/doi.org\/10.1016\/j.ejphar.2012.08.016","journal-title":"Eur J Pharmacol"},{"key":"7738_CR29","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1007\/s40263-012-0017-y","volume":"27","author":"D Devos","year":"2013","unstructured":"Devos D, Moreau C, Delval A et al (2013) Methylphenidate: A treatment for Parkinson\u2019s disease? CNS Drugs 27:1\u201314. https:\/\/doi.org\/10.1007\/s40263-012-0017-y","journal-title":"CNS Drugs"},{"key":"7738_CR30","doi-asserted-by":"publisher","first-page":"1148","DOI":"10.1212\/WNL.0b013e3182886a76","volume":"80","author":"EE Benarroch","year":"2013","unstructured":"Benarroch EE (2013) Pedunculopontine nucleus: Functional organization and clinical implications. Neurology 80:1148\u20131155. https:\/\/doi.org\/10.1212\/WNL.0b013e3182886a76","journal-title":"Neurology"},{"key":"7738_CR31","doi-asserted-by":"publisher","first-page":"693","DOI":"10.1002\/mds.26923","volume":"32","author":"C Gallea","year":"2017","unstructured":"Gallea C, Ewenczyk C, Degos B et al (2017) Pedunculopontine network dysfunction in Parkinson\u2019s disease with postural control and sleep disorders. Mov Disord 32:693\u2013704. https:\/\/doi.org\/10.1002\/mds.26923","journal-title":"Mov Disord"},{"key":"7738_CR32","doi-asserted-by":"publisher","first-page":"9","DOI":"10.1038\/s41531-023-00455-7","volume":"9","author":"A Davin","year":"2023","unstructured":"Davin A, Chabard\u00e8s S, Devergnas A et al (2023) Excessive daytime sleepiness in a model of Parkinson\u2019s disease improved by low-frequency stimulation of the pedunculopontine nucleus. NPJ Park Dis 9:9. https:\/\/doi.org\/10.1038\/s41531-023-00455-7","journal-title":"NPJ Park Dis"},{"key":"7738_CR33","doi-asserted-by":"publisher","first-page":"10","DOI":"10.1002\/mds.27098","volume":"33","author":"W Thevathasan","year":"2018","unstructured":"Thevathasan W, Debu B, Aziz T et al (2018) Pedunculopontine nucleus deep brain stimulation in Parkinson\u2019s disease: A clinical review. Mov Disord 33:10\u201320. https:\/\/doi.org\/10.1002\/mds.27098","journal-title":"Mov Disord"},{"key":"7738_CR34","doi-asserted-by":"publisher","first-page":"880","DOI":"10.1126\/science.aav2546","volume":"363","author":"JK Holth","year":"2019","unstructured":"Holth JK, Fritschi SK, Wang C et al (2019) The sleep-wake cycle regulates brain interstitial fluid tau in mice and CSF tau in humans. Science 363:880\u2013884. https:\/\/doi.org\/10.1126\/science.aav2546","journal-title":"Science"}],"container-title":["Neurological Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1007\/s10072-024-07738-8.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/article\/10.1007\/s10072-024-07738-8\/fulltext.html","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1007\/s10072-024-07738-8.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,1,27]],"date-time":"2025-01-27T09:17:10Z","timestamp":1737969430000},"score":1,"resource":{"primary":{"URL":"https:\/\/link.springer.com\/10.1007\/s10072-024-07738-8"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,9,26]]},"references-count":34,"journal-issue":{"issue":"2","published-print":{"date-parts":[[2025,2]]}},"alternative-id":["7738"],"URL":"https:\/\/doi.org\/10.1007\/s10072-024-07738-8","relation":{},"ISSN":["1590-1874","1590-3478"],"issn-type":[{"value":"1590-1874","type":"print"},{"value":"1590-3478","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,9,26]]},"assertion":[{"value":"11 May 2024","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"20 August 2024","order":2,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"26 September 2024","order":3,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"order":1,"name":"Ethics","group":{"name":"EthicsHeading","label":"Declarations"}},{"value":"Each PPMI site\u2019s institutional review board approved the study.","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Ethical approval"}},{"value":"All participants signed an informed consent form after being fully informed.","order":3,"name":"Ethics","group":{"name":"EthicsHeading","label":"Informed consent"}},{"value":"The authors have no competing interests to declare that are relevant to the content of this article.","order":4,"name":"Ethics","group":{"name":"EthicsHeading","label":"Conflict of interest"}}]}}