Efficacy of Dual-task Telerehabilitation to Prevent Worsening in Activities of Daily Living in People With Parkinson's Disease at High Risk for Dementia: A Proof-of-concept Study

Telerehabilitation is a promising tool for treating and preventing further disease progression in Parkinson's disease (PD) [1, 2]. First studies in people with PD (PwPD) verified the feasibility of home-based digital cognitive training [3-7]. Progression in cognitive impairment and the onset and worsening of problems with complex everyday tasks are hallmarks of the prodromal phase of Parkinson's disease dementia (PDD). Consequently, the risk of PDD conversion is dramatically increased for PwPD with both mild cognitive impairment (PD-MCI) and complex activities of daily living (ADL) problems related to cognitive impairment [8]. Therefore, this group may be a promising target group for interventions, as they are at risk for serious and rapidly progressive cognitive deterioration.

PwPD with PD-MCI show deficits in motor-cognition [9] and attentional-control, both of which affect ADL [10]. Dual-task cognitive trainings (DCT) shows great potential to lower down the disease process [11, 12], but so far no home-based DCT with the primary endpoint of complex ADL and cognition has been conducted in PwPD. We adapted an on-site DCT to improve both physical and cognitive function in PwPD [13]. The training will be conducted as a telerehabilitation training in PwPD with PD-MCI and cognitive ADL impairment, identified with the Functional Activities Questionnaire (FAQ). Of PwPD with PD-MCI who have more cognitive rather than motor associated ADL dysfunction (reflected by a value of the FAQ quotient > 1.008), nearly 50% develop dementia (PDD) within three years [8].

In our single-center randomized, controlled non-pharmacological intervention, 42 PwPD with PD-MCI and FAQ quotient >1.008 will be assessed with pre-(T0) and post(T1), 6-months (T2) and 12-month follow-up (T3) testing. After 1:1 randomization to either the experimental DCT or the control motor training (CMT), both groups will leg-cycle safely in a comfortable chair on a bicycle ergometer, 3 times a week for 30 minutes. While cycling, the DCT group will additionally perform digital cognitive training on a tablet, covering attention, working memory and executive function. The cognitive training will automatically adapt to performance levels and is remotely accessible. The training is aimed to enhance cognition as well as ADL and to prevent its further decline, with an emphasis on maintaining ADLs in the prodromal stage of Parkinson's disease dementia (PDD).