Effectiveness of Lee Silverman Voice Treatment for Improving Motor Function in Patients With Parkinson's Disease: A Systematic Review and Meta-analysis of Randomized Clinical Trials.

Abstract

Lee Silverman Voice Treatment is an exercise program developed for patients with Parkinson's disease. This systematic review and meta-analysis evaluate the benefits of Lee Silverman Voice Treatment on motor function in these patients. A comprehensive search was conducted in Embase, PubMed, Cochrane Library, Scopus, MEDLINE, ScienceDirect, and PEDro up to October 2024. Two investigators reviewed studies comparing Lee Silverman Voice Treatment with other interventions on motor function outcomes. Study quality was assessed using the Cochrane Risk of Bias tool, and certainty of the evidence was evaluated using Grading of Recommendations Assessment, Development, and Evaluation methodology. The search identified 827 studies, with 6 included in the systematic review and 5 in the meta-analysis. Lee Silverman Voice Treatment significantly improved walking speed, as measured by the 10-Meter Walk Test mean difference (MD) -0.60, (95% confidence interval (CI) = -1.17, -0.02, P = 0.04). No significant improvement was found in quality of life (Parkinson's Disease Questionnaire-39 items, MD -2.79, 95% CI = -7.38, 1.80, P = 0.23). Sensitivity analysis revealed significant improvement in motor function (Unified Parkinson's Disease Rating Scale Part III, MD -5.52, 95% CI = -7.72, -3.32, P < 0.05). The certainty of evidence ranged from moderate to low. Lee Silverman Voice Treatment could be more effective than general exercise in improving gait speed and motor function in patients with mild to moderate Parkinson's disease. However, because of the variability in study quality and the limited number of participants, these findings should be interpreted with caution.