Effects and safety of repetitive transcranial magnetic stimulation on cognitive outcomes in mild cognitive impairment: a systematic review and meta-analysis

Across randomized studies, cognitive test scores generally favored active rTMS for mild cognitive impairment. The estimated benefit varied substantially across studies, so the result does not establish an optimal protocol or an improvement in everyday independence.

Ren H, Jiao J, Lan X, Tan C, Wang Z, Pei H, Yao D, Liu T, Dong L.
Frontiers in Aging Neuroscience · Publication date: 2026-09-24
Added to site: 2026-09-27
DOI: 10.3389/fnagi.2026.1894724

Original publication date verified from the publisher and Crossref. This source date is separate from the site's addition date.

Modalities

rTMS, TMS

Clinical focus

Mild cognitive impairment, Cognition, Safety

Population

Adults with mild cognitive impairment

Sample

14 trials contributing 15 datasets; 672 participants in the primary MoCA analysis and 474 participants in the quantitative safety analysis

Intervention / method

Active rTMS compared with sham stimulation or a matched control intervention; protocols varied in frequency, target, intensity, sessions and pulse exposure

Comparator

Sham rTMS or matched control interventions across included randomized trials

Clinician summary

The primary MoCA analysis favored rTMS with Hedges' g 1.46 (95% CI 0.97 to 1.94), but heterogeneity was substantial at I2 = 86%. Ten datasets found no significant increase in reported adverse events versus sham (RR 1.25, 95% CI 0.76 to 2.04).

How to interpret the findings

Only 2 of 14 trials were rated low risk overall, while 8 were high risk and 4 unclear. Blinding was a recurring concern, Egger's test suggested small-study effects for MoCA, protocols and outcome measures varied, and clinically anchored functional outcomes were inconsistent. Five datasets lacked usable quantitative safety information, and long-term or rare harms cannot be excluded.

Equipment and disclosures

All included studies used figure-of-eight coils. Frequencies ranged from 1 to 20 Hz and intensities from 80% to 110% of resting motor threshold; no single product or protocol represents the pooled result.

Supported by Chinese national, Sichuan and Chengdu public research grants. The authors declared no commercial or financial relationships that could be construed as a potential conflict of interest.

Related evidence

Compare findings from the same clinical area, including mixed results.

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• Electroencephalography in Subjective Cognitive Decline and Mild Cognitive Impairment: Systematic Review of Biomarkers, Classification, and Prognostic Evidence. · Positive with limitations