Effects of transcranial direct current stimulation on lower limb function, balance and quality of life after stroke: a systematic review and meta-analysis

Objective This systematic review with meta-analysis aimed to evaluate the effectiveness of tDCS on lower limb function, balance and quality of life in stroke patients.Methods The search included PubMed, CENTRAL, PEDro, Web of Science, SCOPUS, PsycINFO Ovid, CINAHL EBSCO, EMBASE, ScienceDirect, reference lists of relevant reviews, clinical trials registries and academic google, in June and July 2021. Randomized controlled trials were selected, which present the effect of tDCS on lower limb motor function recovery in stroke patients, comparing any type of active tDCS versus sham; parallel or crossover study design; adult patients; stimulation on the primary motor cortex; articles published in any language; without restriction of publication period.Results Nineteen studies were included. The treatment with active tDCS did not improve motor function (Chi2 = 32,87, I2 = 76%, SMD = 0,36 e 95% CI −0,18–0,90). Subgroup analyzes showed a significant effect favorable to tDCS, in relation to motor function, in the acute and subacute post stroke phases. However, the quality of evidence for this outcome was very low. Regarding balance outcome, a meta-analysis showed a significant difference in favor of active tDCS, but the quality of the evidence was considered very low. As for the quality of life outcome, no statistically significant difference was found in favor of tDCS.Discussion There is a lack of evidence in recommending the use of tDCS in isolation in the treatment of patients after stroke, aiming at improving motor function, balance and quality of life. However, it is possible that tDCS can be beneficial when associated with other therapies or interventions.