Two-year smartphone motor monitoring in isolated REM sleep behavior disorder and Parkinson’s disease

Abstract We aimed to assess the sensitivity of key motor smartphone tasks to detect disease progression in subjects with isolated rapid eye movement sleep behavior disorder (iRBD) and early Parkinson’s disease (PD) compared to healthy controls. Twenty-six healthy controls, 22 patients with iRBD and 23 patients with early-stage PD performed speech, psychomotor, hand tremor, and U-turn tasks using a smartphone every 14 days for 24 months. Disease progression in iRBD was observed through monopitch during reading and slowing turn speed (both p < 0.05), whereas in PD, shortening of time to first voice break during phonation ( p < 0.05). Several speech, psychomotor, and U-turn measures showed adequate cross-sectional sensitivity to distinguish iRBD or PD from controls. Significant learning effect in the first year influenced measures derived from oral diadochokinesis, tapping, and hand tremor. This study represents guidance for future remote smartphone trials that integrate diverse motor domains to monitor prodromal and early Parkinsonism.