Effect of Transcranial Direct Current Stimulation Combined With Rehabilitation on Arm and Hand Function in Stroke Patients: A Systematic Review and Meta-Analysis

Stroke is a major cause of chronic disability, as motor deficits in the upper limbs remain a persistent issue for many survivors. Transcranial direct current stimulation (tDCS) is a potential non-invasive neuromodulation method to enhance neuroplasticity, but evidence regarding its effectiveness when paired with rehabilitation remains mixed. This systematic review and meta-analysis aimed to assess the impact of adding tDCS to rehabilitation on upper limb motor recovery and activity. Electronic databases were searched for randomized controlled trials (RCTs) comparing active tDCS (anodal, cathodal, or bihemispheric) plus rehabilitation against sham tDCS plus rehabilitation. The primary endpoint was motor impairment of the upper extremity, evaluated via the Fugl-Meyer Assessment for upper extremity (FMA-UE). Secondary endpoints comprised functional activity, grip strength, and safety profiles. A random-effects model was employed for data synthesis, and risk of bias was evaluated using the Cochrane RoB 2 tool. The analysis included 45 RCTs with 1,568 participants. The combination of active tDCS and rehabilitation demonstrated a statistically significant enhancement in FMA-UE scores relative to sham (mean difference (MD) = 7.11, 95% CI: 5.76 to 8.46; p < 0.0001), surpassing the minimal clinically important difference. Subgroup analysis revealed that the effect was most pronounced in the subacute phase (MD = 11.72) compared to the chronic phase (MD = 4.89). Functional activity also showed significant improvement (standardized mean difference = 0.62). No significant differences were found between stimulation montages (anodal, cathodal, bihemispheric). Adverse events were similar between groups. tDCS appears to provide a clinically meaningful adjunctive benefit to rehabilitation for improving upper limb motor function in stroke patients, particularly in the subacute phase. The findings support the potential integration of tDCS into stroke rehabilitation protocols, although future research should focus on optimizing stimulation parameters and personalizing treatment.