Effects of Cognitive Training on Balance and Motor Symptoms in Parkinson's Disease: An Exploratory Randomized Controlled Trial

Background Cognitive rehabilitation is a potential intervention for cognitive but also motor disorders in Parkinson's disease (PD). Objective To investigate the effects of cognitive rehabilitation on balance and motor symptoms in PD. Methods A randomized controlled trial in a community setting, in people with mild-to-moderate PD (Hoehn and Yahr <= III) without cognitive impairment (MoCA >= 24) was conducted. Thirty-nine participants were randomly allocated to receive a cognitive intervention (Experimental Group, n = 20) or no intervention (Control Group, n = 19). The experimental protocol involved self-administered cognitive rehabilitation using the NeuronUP platform, focusing on sustained attention and information processing speed training (30 min/day, 3 days/week, 4 weeks). The Berg Balance Scale (BBS) was the main outcome. Motor variables included UPDRS-III, Percentage of Limits of Stability (%LOS) and Timed Up and Go Test (TUG). Neuropsychological variables included TMT-A, TMT-B, Processing Speed (Digit Symbol-Coding and Symbol Search) and Stroop test. Results At post-intervention, marginal improvements were observed in BBS (Mean Difference = 2.23 points, 95%CI [-0.03, 4.49], p = 0.053) and significant improvements in the UPDRS-III (Mean Difference = -4.02 points, 95%CI [-7.82, -0.23], p = 0.039). No significant improvements were found in the rest of the motor and cognitive variables. Conclusions Self-administered cognitive training did not improve balance or cognition but significantly reduced motor symptom severity in PD. The effect of more intensive or in-person cognitive rehabilitation protocols on balance needs to be evaluated.