Search

International audience; Objective: We aimed to identify timing distortions in production and perception of rhythmic events in patients with idiopathic REM sleep behavior disorder (iRBD) as early markers of Parkinson's disease (PD).Methods: Rhythmic skills, clinical characteristics, dysautonomia, depression, and olfaction were compared in 97 participants, including 21 participants with iRBD, 38 patients with PD, and 38 controls, matched for age, gender, and education level. Rhythmic disturbances can be easily detected with dedicated motor tasks via a tablet application. Rhythm production was tested in two conditions: to examine the ability to generate a spontaneous endogenous rhythm, tapping rate and variability in a finger tapping task without external stimulation was measured, while the ability to synchronize to an external rhythm was tested with finger tapping to external auditory cues. Rhythm perception was measured with a task, in which the participants had to detect a deviation from a regular rhythm. Participants with iRBD had dopamine transporter imaging.Results: Participants with iRBD and PD revealed impaired spontaneous rhythm production and poor rhythm perception compared to controls. Impaired rhythm production was correlated with olfaction deficits, dysautonomia, impaired non-motor aspects of daily living, and dopamine uptake measures.Conclusions: Participants with iRBD show impaired rhythm production and perception; this impairment is correlated with other early markers for PD. Testing rhythmic skills with short and inexpensive tests may be promising for screening for potential future PD in iRBD patients.

Background: Walking regularly in Parkinson’s disease has beneficial effects on movement and quality of life. Yet, patients usually show reduced physical activity compared to healthy older adults. Using auditory stimulation, such as music, can facilitate walking but patients vary significantly in their response to the stimulus. An individualized approach adapting musical tempo to patients’ gait cadence, and capitalizing on these individual differences, is likely to provide a rewarding experience, with beneficial effects on gait in Parkinson’s disease. We aim to evaluate the observance, safety, tolerance, usability and enjoyment of a new smartphone application coupled with wearable sensors (BeatPark) delivering individualized musical stimulation for gait auto-rehabilitation at home. Methods: Forty-five patients with Parkinson’s disease underwent a one month, outdoor, gait rehabilitation program, using the BeatPark application (30 min/day, 5 days/week). The music tempo was aligned in real time to patients’ gait cadence while fostering an increase of cadence up to +20% of the patient’s preferred cadence. Evaluation was based on BeatPark use measures, questionnaires and a six-minute walk test before and after the rehabilitation program. Findings: Patients used the application 78.8 % (±28.2) of the prescribed duration and mostly enjoyed it, across the whole program. 75 % of them rated the application as easy to use. While using BeatPark, patients increased their ‘walk for exercise’ duration and frequency, reduced their fear of falling, and improved their quality of life. After the program, they improved their gait parameters in the six-minute walk test. Interpretation BeatPark is an easy to use and enjoyable musical application for individualized gait rehabilitation in Parkinson’s disease increasing ‘walk for exercise’ duration, confidence in gait and quality of life. Trial Registration: NCT02647242 Funding: This research was supported by a European grant: BeatHealth: Health and Wellness on the Beat (EU FP7-ICT contract #610633). Declaration of Interests: None to declare. Ethics Approval Statement: The study was approved by the National Ethics Committee (CPP Sud Mediterannee III, Nimes, France, ID-RCB: 2015-A00531-48). All participants gave written informed consent before participating.