Electroconvulsive Therapy for Parkinson's Disease: A Systematic Review and Meta-Analysis

Background: Electroconvulsive therapy (ECT) is a well-established treatment for psychiatric disorders, including depression and psychosis. ECT has been reported to be effective in treating such psychiatric symptoms in patients with Parkinson's disease (PD) and has been also reported to be effective in treating motor symptoms. The aim of the study is to summarize previous clinical studies investigating the efficacy of ECT for symptoms in patients with PD. Methods: A systematic review and meta-analysis of any study designs assessing motor and/or non-motor symptoms in patients with PD before and after ECT. Co-primary outcomes were set as motor manifestations assessed using the Unified Parkinson's Disease Rating Scale or other rating scales, and non-motor symptoms included depression and psychosis. Secondary outcomes were wearing-off phenomenon and cognitive function. The impact of ECT on those symptoms was examined by comparing the severity of the symptoms before and after ECT using a random effect model and was expressed in standardized mean difference. Results: Of 1219 identified citations, 14 studies (n = 129; 1 randomized controlled study, 9 prospective observational studies, and 4 retrospective studies) were analyzed. The findings were as follows: ECT significantly improved motor manifestations in patients with PD, and the improvement was significant in the subpopulation without psychiatric symptoms; ECT significantly improved depression and psychosis; and ECT significantly relieved wearing-off phenomenon and did not worsen cognitive functioning. Conclusion: The current meta-analysis suggests the potential benefit of ECT on motor and non-motor symptoms in presumably complicated and difficult-to-treat subgroups.