Transcranial Direct Current Stimulation in Motor Therapy for Patients With Parkinson’s Disease: A Systematic Review

Abstract

Parkinson’s disease (PD) is a neurodegenerative disorder that leads to motor and non-motor impairments, including tremors, bradykinesia, and rigidity. Current treatments, such as pharmacological therapies and deep brain stimulation, have efficacy and side effects limitations. Transcranial direct current stimulation (tDCS) is a non-invasive technique that may offer a complementary approach to managing PD motor symptoms. This review aims to evaluate the efficacy of tDCS in improving motor outcomes in PD patients. This systematic review followed PRISMA guidelines and was registered on the PROSPERO platform (CRD4202457096). We included randomized controlled trials (RCTs) that assessed tDCS in PD patients with a control group. Studies were identified through PubMed, Embase, and Cochrane Library searches up to January 2025. Data on participant demographics, interventions, outcomes, and results were extracted and analyzed. Risk of bias was assessed using the Cochrane RoB 2 tool. Five studies involving 176 participants (mean age 67.13 years) were included. Results indicated that tDCS improved motor outcomes, including gait, posture, and balance. Notably, it demonstrated enhanced dual-task gait speed and improvements in gait cadence. Also, it was reported that there were reductions in freezing of gait severity, while improvements in trunk stability and postural control. Despite promising findings, heterogeneity across studies was observed, particularly regarding stimulation parameters and outcome measures. This review provides evidence that tDCS can improve motor symptoms in PD, particularly gait and posture. However, variability in stimulation protocols and small sample sizes limit generalizability. Larger, standardized trials are needed to confirm tDCS’s efficacy, optimize treatment parameters, and assess long-term effects. tDCS shows potential as an adjunctive therapy for managing motor symptoms in PD patients.