Efficacy of repetitive transcranial magnetic stimulation in Parkinson's disease: an updated systematic review and meta-analysis of randomized controlled trials.

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) has emerged as a potential noninvasive treatment option for managing motor and non-motor symptoms in Parkinson's disease (PD). While numerous randomized controlled trials have evaluated its efficacy, the evidence remains inconsistent. This updated systematic review and meta-analysis aims to consolidate the available data to assess the effectiveness of rTMS in improving motor symptoms, cognitive function, and quality of life in patients with PD.

METHOD: A comprehensive search was conducted across multiple databases, including PubMed, Scopus, and Cochrane Library, from their inception to December 2024. Randomized controlled trials (RCTs) comparing rTMS with sham stimulation or other controls in patients with PD were included. The primary outcome was improved motor symptoms, as measured by the Unified Parkinson's Disease Rating Scale (UPDRS) part III or MD-UPDRS-III. Data were pooled using a random effects model, and heterogeneity was assessed with the I 2 statistic.

RESULTS

A total of 20 RCTs, including 693 participants, met the inclusion criteria. rTMS was associated with significant improvements in UPDRS-III (standardized mean difference [SMD] 0.53 [0.31, 0.74], I 2 = 28%, P < 0.00001) and MD-UPDRS-III (SMD 0.42 [0.19, 0.66], I 2 = 0%, P = 0.0005) scores. Cognitive function, assessed by Mini-Mental State Exam, showed no significant improvement. Beck Depression Inventory (SMD 0.36 [0.12, 0.61], I 2 = 0%, P = 0.003) showed significant improvement. However, both HDRS (SMD 0.16 [-0.16, 0.47], I 2 = 0%, P = 0.33) and MADRS (SMD 0.55 [-0.31, 1.41], I 2 = 63%, P = 0.21).

CONCLUSION

This updated meta-analysis provides evidence that rTMS is a safe and effective intervention for improving motor symptoms and cognitive function in PD patients. However, its effects on mood and long-term outcomes require further investigation.