Disorders of Gait, Postural Stability and Cognition in Parkinson's Disease: Presymptomatic Detection and Targeted Rehabilitation

* Background: In a pilot study, Milman et al. 2014 showed that computer-based cognitive training focusing on executive function and attention performed at home might improve selected gait parameters in early patients with Parkinson´s disease (PD). * Goal 1: To explore this effect in advanced PD patients * Hypothesis 1: Effect of cognitive training focusing on executive function and attention will be detected also in advanced PD patients and this effect will be larger as compared to the results published by Milman et al. 2014. * Goal 2: To verify the results published by Milman et al. 2014 using more targeted clinical and instrumental gait assessment, including dual-task gait evaluation as well as instrumental testing of turn fluency (Bertoli et al. 2019). * Hypothesis 2: The results published by Milman et al. 2014 will be confirmed and an effect on dual-task gait and turn fluency will be shown. * Goal 3: To explore the role of the form of therapy setting, i.e. whether group setting might increase the effect of cognitive training on gait as compared to individual cognitive training at home. Such results have been shown in the case of a physiotherapy intervention by King et al. 2015. * Hypothesis 3: The effect of group cognitive training on gait will be larger as compared to individual dose-matched, computer-based cognitive training performed at home. However, it remains to be determined whether the effect size difference between the two groups will outweigh the advantages of tele-rehabilitation. * Design: Randomised-controlled trial * Interventions: experimental group: group cognitive training focusing on executive function and attention; control group: computer-based cognitive training focusing on executive function and attention performed at home. Intervention in both groups will be dose-matched (experimental: 60 mins, 2x/week, 12 weeks; control: 30 mins, 4x/week, 12 weeks) * Follow-up: at 1 and 3 months time points. * Power analysis results: at least 38 patients.