Repetitive transcranial magnetic stimulation for cognitive and emotional symptoms in neurodegenerative diseases: a systematic review and dose-response meta-analysis.

OBJECTIVE

We summarized the existing clinical evidence of repetitive transcranial magnetic stimulation (rTMS) for cognitive and emotional symptoms in Parkinson's disease (PD) and alzheimer's disease (AD), and conducted a series of dose-response meta-analyses to determine the magnitude and curve relationship between pulse quantity changes and treatment effect sizes.

METHODS

We retrieved existing evidence from 5 databases and collected relevant results data on rTMS treatment for cognitive and emotional symptoms in PD and AD. We analyzed the data using R software to evaluate the effect size using MD or SMD and 95% confidence intervals (CI), used heterogeneity tests to evaluate the differences in efficacy among the evidence, and used restricted cubic splines (RCS) to fit the dose-response curve.

RESULTS

A total of 17 studies were included in this study. We found that the total pulse quantity showed a significant bell-shaped curve in MoCA (χ2 = 6.82, df = 2, p = 0.03), HAMA (χ2 = 9.16, df = 2, p = 0.01), and ADL (χ2 = 8.22, df = 2, p = 0.01), with optimal effects achieved at 16153, 12138, and 17,237 pulses respectively-indicating that clinical application should control pulses within these ranges to avoid insufficient or excessive doses weakening efficacy. A significant upward curve was observed in MMSE (χ2 = 12.94, df = 2, p = 0.001), meaning higher pulse counts (up to the 80,000-pulse upper limit in this study) may further improve basic cognitive function, providing a reference for dose adjustment in patients with cognitive impairment.

CONCLUSION

Our meta-analysis results show that rTMS exhibits significant efficacy in cognitive and emotional symptoms of PD and AD. The dose-response results show that the total pulse quantity in MoCA, HAMA, and ADL of PD and AD patients presents a typical bell-shaped curve, and a typical upward curve in MMSE. This indicates that there is a curve relationship between pulse stimulation quantity and efficacy, and the pulse stimulation quantity should be emphasized in the clinical application of rTMS.