Background: To evaluate the effects and optimal parameters of repetitive transcranial magnetic stimulation (rTMS) on cognition function of Parkinson's disease (PD) patients and to estimate which cognitive function may obtain more benefits from rTMS. Method: The articles dealing with rTMS on cognition of PD patients were retrieved from the databases until April 2019. Two researchers selected research papers, evaluated their quality, extracted data, and cross-checked them according to the

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... n and exclusion criteria. The standardized mean differences (SMDs) with 95 % confidence interval (CI) of cognitive outcome for different parameters, scales, and cognitive functions were estimated. Results: Fourteen studies involving 173 subjects were included in the study. A significant effect size was observed with the mini-mental state examination (MMSE) for the global cognitive outcome based on the evidence of four published articles. Further subtests for different cognitive domains demonstrated prominent effect for the executive function. The significant effect sizes for executive function were found with multiple sessions of high-frequency rTMS over frontal cortex, especially over dorsolateral prefrontal cortex (DLPFC). All of the other cognitive domains including memory, attention, and language ability did not obtain significant effects. Conclusions: Multiple sessions of high-requency rTMS over the DLPFC may have positive effect on executive function in PD patients. Further well designed studies with large sample sizes are needed to verify our results and ascertain the long-term effects of rTMS.