Efficacy of Repetitive Transcranial Magnetic Stimulation over the Supplementary Motor Area on Motor Function in Parkinson's Disease: A Meta-Analysis.

Objectives: The objective of this study was to assess the effect of repetitive transcranial magnetic stimulation (rTMS) on the supplementary motor area (SMA) in motor function in Parkinson's disease (PD) patients.

Method: Databases searched included 5 databases from October 7,2022 to January 4, 2023. The Cochrane Bias Risk Assessment Tool was used for quality assessment. Standardized mean differences (SMDs) were calculated using a random-effects model. Outcome measure is the motor function examination of the motor part of Unified Parkinson's Disease Rating Scale (UPDRS-III).

Results: Seven studies totaling 374 patients were included. Meta-analysis showed that stimulation of SMA significantly improved motor function in PD patients compared with sham stimulation (SMD = -1.24; 95% CI, -2.24 to -0.24; P = 0.02; I 2 = 93%). Stimulation of the same target (SMA), subgroup analysis showed that high-frequency rTMS (HF-rTMS) is more effective than low-frequency rTMS (LF-rTMS) in improving motor function in PD (SMD = -1.39; 95% CI, -2.21 to -0.57; P = 0.04; I 2 = 77.2%).

Conclusions: Overall, rTMS over SMA had a statistically significant improvement in motor function in PD patients, and HF-rTMS is statistically significantly more effective than LF-rTMS.