Impact of Transcranial Direct Current Stimulation on Dual-Task Gait Performance in Parkinson's Disease: A Systematic Review.

BackgroundParkinson's disease (PD) impairs motor and cognitive functions, increasing fall risk during dual-task activities. While transcranial direct current stimulation (tDCS), a non-invasive brain stimulation technique, has been studied for improving these functions in PD, its effect on dual-task gait remains unclear.ObjectiveThis review aims to evaluate the effects of tDCS on dual-task gait performance in PD.MethodsA systematic search was conducted in PubMed, Embase, and Web of Science for studies published before September 2024. Eligible studies included PD patients, used tDCS, and measured dual-task gait performance. Two researchers independently assessed methodological quality using the Cochrane Risk of Bias tool.ResultsFour randomized controlled trials and four crossover studies, involving 222 PD patients (mean age 64.17 years, range 50.9-72) at Hoehn & Yahr stages 1-3, met the inclusion criteria. Three of six studies targeting the dorsolateral prefrontal cortex showed significant improvements in dual-task gait performance, particularly in gait speed (p ≤ 0.046), compared to sham. No significant improvements were observed with primary motor cortex or cerebellar stimulation (all p's ≥ 0.100).ConclusionstDCS targeting the dorsolateral prefrontal cortex may improve dual-task gait performance in PD, but further studies are needed to refine protocols and confirm its therapeutic potential.