Turning alterations detected by mobile health technology in idiopathic REM sleep behavior disorder

Abstract

Abstract Introduction: Idiopathic REM sleep Behavior Disorder (iRBD) is a condition at high risk of developing Parkinson’s disease (PD) and other alpha-synucleinopathies. Aim of the study was to evaluate subtle turning alterations by using Mobile health technology (MHT) in iRBD individuals without subthreshold parkinsonism.Methods A total of 148 participants (23 persons with polysomnography-confirmed iRBD without subthreshold parkinsonism, 60 drug-naïve PD patients and 65 age-matched controls (HC)) were included in this prospective cross-sectional study. All underwent a multidimensional assessment including cognitive and non-motor symptoms assessment. Then a Timed-Up-and-Go test (TUG) at normal and fast speed was performed using MHT (Rehagait®, Hasomed, Germany). Durations, mean and peak angular velocities of the turns were compared using a multivariate model correcting for age and sex.Results Compared to HC, PD patients showed longer turn durations and lower mean and peak angular velocities of the turns in both TUGs (all p ≤ 0.001). iRBD participants showed also a longer turn duration and lower mean (p = 0.006) and peak angular velocities (p < 0.001) compared to HC, but only in the TUG at normal speed.Conclusion MHT assessment identified subtle alterations of turning at normal speed in iRBD patients. The lack of difference between iRBD patients and HC at fast speed may indicate the presence of (unconscious) compensation mechanisms that are activated during challenging mobility conditions. Longitudinal studies are warranted to evaluate the value of objective turning parameters in defining the risk of conversion to PD in iRBD and in tracking motor progression in prodromal PD.