tDCS Combined with CIMT for Post-stroke Upper Extremity Rehabilitation: Systematic Review and Meta-Analysis

Background: Transcranial direct current stimulation (tDCS) has been widely used as an adjunctive treatment for motor function after stroke. Objective: To quantify the effect of tDCS combined with constraint-induced movement therapy (CIMT) on the functional recovery of the upper limb after stroke. Methods: By May 2024, two independent authors screened relevant randomized controlled trials (RCTs) published in English from PubMed, Embase, Web of Science and the Cochrane Library. Publication bias was assessed using the Egger's test. Results: Of the 221 retrieved records, seven publications met the criteria for systematic review and quantitative analysis. According to estimates of Hedges'g, significant effects were revealed from Fugl-Meyer Assessment for Upper Limbs (UL-FMA) for upper limb impairment (g = 0.587, 95% CI = 0.256 to 0.919, p < 0.05) and Motor Activity Log-Amount of Movement (MAL-AoM) for perceived amount of motor (g = 0.386, 95% CI = 0.030 to 0.743, p < 0.05). Significant results favoring combined therapy were not found in Motor Activity Log-Quality of Movement (MAL-QoM) (g = 0.181, 95% CI = -0.169 to 0.531, p > 0.05), grip strength (g = 0.135, 95% CI = -0.214 to 0.485, p > 0.05) or Wolf Motor Function Test (WMFT) (g = 0.210, 95% CI = -0.117 to 0.537, p > 0.05). Conclusions: Our findings confirmed that tDCS enhanced the effect of CIMT in improving upper limb impairment and perceived amount of motor in daily life after stroke.