Recent studies have proved that repetitive transcranial magnetic stimulations(rTMS) could improve cognitive function in people with Alzheimer's disease (AD). However, it remains controversial in clinical effects. In this work, Embase, medline, Cochrane Library, Ovid, Pubmed, Web of science, and Chinese Database are searched for studies of rTMS treatment on AD patients with cognitive impairment published before 2015, and randomized studies with relevant primary outcomes of cognition are included. The outcome is expressed as the standardized mean difference (SMD) and 95% confidence interval (CI). Five studies, comprising a total sample size of 223 AD patients (137 from stimulation groups, 86 from control groups), are included in this meta-analysis. The effect of RTMS treatment on cognition is found in the outcome of MMSE (SMD=1.05, 95% CI:0.21,1.88, p=0.01, n=141). Subgroup analysis shows that high frequency stimulation (>1 Hz) (p= 0.02) but not low frequency stimulation (≤1 Hz) (p=0.27) is significantly effective in improving cognition of AD patients. The outcome of ADAS-cog shows that rTMS treatment is significantly effective in improving cognition of AD patients (SMD=-0.71, 95% CI:-1.04,-0.39, p< 0.0001, n=168). High frequency stimulation (>1 Hz) (p<0.001) is significantly effective compared to the low frequency stimulation (≤1 Hz) (p=0.05). Transcranial magnetic stimulation has significant therapeutic effect on cognitive function in Alzheimer's patients. High frequency stimulation is significantly effective compared to the low frequency stimulation. Due to the small number of studies included, more studies should be evaluated in AD patients in the future.

Alzheimer's disease  /  transcranial magnetic stimulation  /  meta-analysis  /  randomized cotrolled trial