Non-invasive Brain Stimulation Combined with Exercise on Gait in Patients with Parkinson's Disease: Systematic Review and Meta-Analysis

Background Effects of Non-invasive brain stimulation (NIBS) combined with exercise on gait in patients with Parkinson's disease (PD) have been highly inconsistent.Objective To assess the clinical effects of NIBS combined with exercise on gait in PD and analyze the specifics of the intervention protocols related to the outcomes.Methods PubMed, Web of Science, Embase, and Cochrane Library were searched up to July 2023. Included were randomized controlled trials that investigated how NIBS combined with exercise affected gait in PD.Results We examined nine studies, comprising 242 patients, for our meta-analysis. According to our findings, NIBS combined with exercise improved TUGT time (MD -0.83; 95% CI, -1.48 to -0.17) and gait parameters including stride length (MD 19.93; 95% CI, 3.06 to 36.81). In subgroup analyses of different intervention types, UPDRS-III scores were significantly reduced by repetitive transcranial magnetic stimulation (rTMS) combined with exercise (MD -5.63; 95% CI, -9.31 to -1.95) and NIBS combined with treadmill training (MD -5.95; 95% CI, -10.12 to -1.79). TUGT time (MD -1.07; 95% CI, -1.94 to -0.20) and cadence (MD -6.06; 95% CI, -10.24 to -1.87) were significantly affected by transcranial direct current stimulation (tDCS) combined with exercise. NIBS combined with physical therapy produced a notable improvement in TUGT time (MD -1.31; 95% CI, -2.37 to -0.26).Conclusions NIBS combined with exercise may have synergistic effects on gait performance in PD. To achieve the greatest benefits for individuals with PD, future research should concentrate on identifying the most appropriate stimulation parameters and intervention features.