Combining transcranial direct-current stimulation with gait training in patients with neurological disorders: a systematic review.

Only eight controlled trials were included, with 187 participants across stroke, Parkinson's disease and spinal cord injury. The trials used different electrode placements, current densities, session durations, number of sessions and gait training methods, so the results could not be compared directly. Some positive findings came from very small groups, including two participants in one sham group and four participants in one intervention group for the Timed Up and Go variable. Only some trials had follow-up, and only two positive trials with follow-up showed an effect that lasted up to one month. Adverse effects were not investigated systematically, although none were reported. Participants were analysed only if they completed the study, so the review may not show what happens to patients who stop treatment. The review excluded studies with fewer than five sessions or fewer than five participants in the stimulation group, which may have removed relevant evidence. The review included only English or Spanish trials.

Do not read the positive results as proof that tDCS improves walking by itself. The included trials combined active tDCS with gait training, and the review found no conclusive support for that combination.