The effect of repetitive transcranial magnetic stimulation on immediate and long-term cognitive functions in Alzheimer's dementia and mild cognitive impairment: a meta-analysis.

Many included trials had intermediate or high risk of bias: 7 studies were high risk, 15 intermediate, and only 4 low risk. The pooled immediate effect was very inconsistent across studies (I2 90.00%), and the long-term effect was also inconsistent (I2 72.0%). Only 9 studies reported long-term follow-up, so the long-term estimate is based on a small set of trials. The long-term result may be affected by publication bias; the authors note the delayed cognitive efficacy results may have certain publication bias. Parameter subgroup findings are exploratory and confounded: the 80%MT subgroup also tended to have longer session duration and total treatment time, so the effect cannot be pinned to intensity alone. AD and MCI patients were analysed together even though they are different clinical stages and may respond differently. All included patients were over 60 years old, so the paper does not address younger MCI or AD populations. Outcomes were cognitive screening or dementia scale scores, not communication, daily functioning, safety, or long-term clinical benefit.

The paper names one funder: Key Project of Medical and health technology of Longgang District, Shenzhen.

Do not read the subgroup results as a proven best rTMS protocol. The paper found larger immediate effects with DLPFC stimulation, lower intensity subgroups, total time over 800 min, and more than 20 sessions, but these were subgroup comparisons with high heterogeneity and confounded protocol combinations, and the authors say the parameter conclusions need caution.