Transcranial direct current stimulation provides no clinically important benefits over walking training for improving walking in Parkinson's disease: a systematic review.

Abstract Questions Does walking training combined with transcranial direct current stimulation (tDCS) improve walking (ie, speed, cadence and step length) and reduce falls and freezing, compared with no/sham intervention, in people with Parkinson's disease? Is walking training combined with tDCS superior to walking training alone? Are any benefits carried over to social participation and/or maintained beyond the intervention period? Design A systematic review with meta-analyses of randomised clinical trials. Participants Ambulatory adults with a clinical diagnosis of Parkinson's disease. Intervention tDCS combined with walking training. Outcome measures Primary outcomes were walking speed, cadence and step length. Secondary outcomes were number of falls, fear of falling, freezing of gait and social participation. Results Five trials involving 117 participants were included. The mean PEDro score of the included trials was 8 out of 10. Participants undertook training for 30 to 60 minutes, two to three times per week, on average for 4 weeks. Moderate-quality evidence indicated that the addition of tDCS to walking training produced negligible additional benefit over the effect of walking training alone on walking speed (MD −0.01 m/s, 95% CI −0.05 to 0.04), step length (MD 1.2 cm, 95% CI −1.2 to 3.5) or cadence (MD −3 steps/minute, 95% CI −6 to 1). No evidence was identified with which to estimate the effect of the addition of tDCS to walking training on freezing of gait, falls and social participation. Conclusion The addition of tDCS to walking training provided no clinically important benefits on walking in ambulatory people with Parkinson's disease. Registration PROSPERO CRD42020162908.