A systematic review and meta-analysis on the effectiveness of transcranial direct current stimulation (tDCS) on swallowing function of post-stroke patients.

OBJECTIVE: The purpose of this study was to investigate the therapeutic effects of transcranial direct current stimulation (tDCS) on swallowing function in post-stroke patients.

DESIGN: We searched for potentially eligible randomized controlled trials from electronic databases, including the PubMed, Embase, Web of Science, Cochrane Library, China National Knowledge Infrastructure, Wanfang, and Chinese Science and Technology Periodical (VIP) databases, from their inception to January 15, 2021. All statistical analyses were performed using RevMan 5.4, and the standardized mean difference with 95% confidence intervals was estimated for the swallowing function outcomes and to understand the mean effect size.

RESULTS: Ten studies involving 343 participants were included in this meta-analysis. The overall analyses demonstrated a significant effect size for swallowing function. Subgroup analyses suggested that both acute and chronic stroke patients showed significant effects on swallowing function after tDCS. Furthermore, compared with sham stimulation, tDCS anodal to the affected, unaffected, and bilateral hemispheres can produce a significant effect size for swallowing function in stroke patients.

CONCLUSIONS: This meta-analysis showed that tDCS is likely to be effective for the recovery of dysphagia in post-stroke patients, in the acute or chronic phase, and that the effect of anodal tDCS to unaffected hemispheres is larger.