The Effects of Neuromodulators on Spasticity, Balance, and Gait in Patients with MS: A Systematic Review and Meta-Analysis Study

Introduction: Multiple sclerosis (MS) is a common neurological disorder in societies. The most common symptoms in patients with MS are gait disorders and spasticity. Pharmacological therapies have mild therapeutic influence with more side effects for management of these symptoms. There is evidence that neuro-rehabilitation techniques have more appropriate effects rather than pharmacological therapies. In this regard, some studies indicated the beneficial effects of brain stimulation techniques on gait improvement and decreasing spasticity in patients with MS, while the others have not shown any efficacy. Accordingly, conducting a meta-analysis study in this issue is very important. Methods: A systematic search was performed in PubMed, Scopus, and ISI Web of Science from database inception on December 6, 2020, to find interventional studies assessing the effects of neuromodulators (transcranial direct-current stimulation [tDCS] or transcranial magnetic stimulation [TMS]) on spasticity, balance, and gait in patients with MS. The included studies were qualitatively assessed by the Physiotherapy Evidence Database (PEDro) scale. Finally, the homogeneity studies were analyzed by Stata software. Study-specific results were pooled by using a random-effects model. Results: A total of seven studies were included in the analysis. In the pooled analysis of studies, a significant effect of the TMS technique on spasticity was observed in patients with MS: -0.80 (95% CI: -1.31, -0.29). In addition, no significant effect of the single-session tDCS technique on gait speed was observed in patients with MS: 0.11 (95% CI: -0.11, 0.32). Conclusions: One of the main causes of discrepancy in the findings of included studies is the number of sessions for using neuromodulator techniques. A single session of anodal tDCS is not enough to improve gait in patients with MS. In addition, meta-analysis shows that multi-session TMS is effective intervention for decreasing spasticity in patients with MS.