BACKGROUND: Parkinson's disease (PD) comorbid with rapid eye movement sleep behavior disorder (RBD) may show more severe motor and nonmotor symptoms, suggesting a distinct PD subtype.
OBJECTIVE: The aim of this study was to investigate the impact of RBD on the longitudinal change of motor and nonmotor symptoms in patients with PD.
METHODS: Patients with early PD (diagnosed within 3.5 years) recruited from 2010 to 2019 were followed every 18 months in the Oxford Parkinson's Disease Centre Discovery cohort. At each visit, we used standard questionnaires and measurements to assess demographic features and motor and nonmotor symptoms (including RBD, daytime sleepiness, mood, autonomic symptoms, cognition, and olfaction). Data were analyzed with linear mixed effects and Cox regression models. Possible RBD (pRBD) was longitudinally determined according to RBD Screening Questionnaire scores.
RESULTS: A total of 923 patients were recruited (mean age: 67.1 ± 9.59 years; 35.9% female), and 788 had follow-up assessment(s) (mean: 4.8 ± 1.98 years, range: 1.3-8.3). Among them, 33.3% were identified as pRBD (PD + pRBD). Patients with PD + pRBD had more severe baseline symptoms and showed faster progression on Movement Disorder Society-Unified Parkinson's Disease Rating Scale parts I and III, Purdue Pegboard test, and Beck Depression Inventory scores. Moreover, PD + pRBD was associated with an increased level of risk for mild cognitive impairment (hazard ratio [HR] = 1.36, 95% confidence interval [CI]: 1.01-1.83), freezing of gait (HR = 1.42, 95% CI: 1.10-1.86), and frequent falling (HR = 1.62, 95% CI: 1.02-2.60).
CONCLUSIONS: Patients with PD + pRBD progress faster on motor, mood, and cognitive symptoms, confirming a more aggressive PD subtype that can be identified at baseline and has major clinical implications. © 2021 International Parkinson and Movement Disorder Society.
Bibliographical noteFunding Information:
This study was funded by the Monument Trust Discovery Award from Parkinson's UK (J‐1403) and supported by the National Institute for Health Research (NIHR) Oxford Biomedical Research Centre (BRC).
Dr. Yaping Liu was supported by the Postdoctoral Fellowship in Clinical Neurosciences of the Chinese University of Hong Kong. Michael A. Lawton has nothing to report. Dr. Christine Lo was funded from the NIHR Oxford Biomedical Research Centre. Francesca Bowring has nothing to report. Johannes C. Klein is supported by the NIHR Oxford Health Clinical Research Facility. Dr. Agustin Querejeta‐Coma has nothing to report. Dr. Sangeeta Scotton has nothing to report. Jessica Welch has nothing to report. Dr. Jamil Razzaque has nothing to report. Dr. Thomas Barber has nothing to report. Prof. Yoav Ben‐Shlomo has nothing to report. Prof. Michele Hu has nothing to report.
© 2021 International Parkinson and Movement Disorder Society