Efficacy analysis of three brain stimulation techniques for Alzheimer’s disease: a meta-analysis of repeated transcranial magnetic stimulation, transcranial direct current stimulation, and deep brain stimulation

ABSTRACT

Introduction

This systematic review and meta-analysis study investigates the efficacy of repeated transcranial magnetic stimulation (rTMS), transcranial direct current stimulation (tDCS), and deep brain stimulation (DBS) using neuropsychological assessments as a potential treatment option for Alzheimer's disease (AD).

Methods

PubMed, Embase, and the Cochrane Library were searched for studies on rTMS, tDCS, and DBS for the treatment of patients with AD between April 1970 and October 2022. The mini-Mental State Examination (MMSE) and AD Assessment Scale – Cognitive Subscale (ADAS-Cog) were adopted as the efficacy index.

Results

The analysis yielded 17 eligible studies. rTMS greatly improved the cognition of patients with AD (immediate post-treatment WMD of MMSE score: 2.06, p < 0.00001; short-term follow-up WMD of MMSE score: 2.12, p = 0.006; WMD of ADAS-Cog score in single-arm studies: -4.97, p = 0.001). DBS did not reverse the progression of cognitive decline (WMD of ADAS-Cog score in single-arm studies: 7.40, p < 0.00001). Furthermore, tDCS demonstrated no significant efficacy in improving cognition in random clinical trials or single-arm studies.

Conclusion

rTMS is a promising non-medicinal alternative for cognitive improvement inpatients with AD.

KEYWORDS:

• Alzheimer’s disease
• cognition
• repeated transcranial magnetic stimulation
• transcranial direct current stimulation
• deep brain stimulation

Author contributions

Peilin Huang and Lin Lin were involved in the conception and design, analysis, interpretation of the data, and the drafting of the paper; Jiejun Zhang and Yingzhe Cheng took part in the interpretation of the data; Xiaodong Pan revised it critically for intellectual content and the final approval of the version to be published; and that all authors agree to be accountable for all aspects of the work.

Acknowledgments

We sincerely thank Professor Hongzhi Huang from the School of Arts and Sciences of Fujian Medical University, who carefully proofread and polished this manuscript, and Dr. Kaiyan Huang of Fujian Medical University for his technical guidance.

Declaration of interest

The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Supplementary Material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/14737175.2023.2293225

Additional information

Funding

The authors declare funding from the Joint Funds for the Innovation of Science and Technology, Fujian province (No. 2021Y9037); and the Key Project of Natural Science Foundation of Fujian Province (No. 2020J02022).