Efficacy of transcranial direct current stimulation combined with gait training in patients with Parkinson's disease: Systematic review and meta-analysis

Abstract

Parkinson's disease, the second most prevalent neurological disorder, is a multisystem neurodegenerative disease characterized by both motor and non-motor symptoms. Transcranial direct current stimulation (tDCS) is a non-invasive brain neuromodulation technique that has been shown to be effective in some neurological conditions and for some clinical outcomes. To evaluate the efficacy of tDCS combined with gait training in Parkinson's disease, compared to placebo, absence of treatment, conventional therapy, or other therapies. A systematic review and meta-analysis were performed in accordance with the PRISMA guidelines and registered in PROSPERO CRD42024542552. The literature search was conducted in PubMed, CINAHL, SPORT Discus, Web of Science, Scopus, MEDLINE, and Academic Search Ultimate (EBSCO) databases up to May 2024, limited to trials from the last 10 years. A total of 600 articles were identified; 9 were included in the systematic review and 8 in the meta-analysis. Significant intra-group changes were observed, but in the meta-analysis, no significant differences were seen between tDCS + gait training and tDCS placebo + gait training, although variables such as motor function slightly favored the combination (MD = -0.49; 95% CI [-1.55; 0.57], I2 = 0%). The combination of tDCS and gait training could provide significant motor benefits in terms of gait speed, functional mobility, cadence, motor function, quality of life, 6MWT, coordination and dynamic balance, flexibility, and stretch resistance in patients with Parkinson's disease, but not in a more effective way than the same training without stimulation.