Efficacy of repetitive transcranial magnetic stimulation in treating stroke aphasia: Systematic review and meta-analysis

Objective: This meta-analysis examined the effectiveness of repetitive Transcranial Magnetic Stimulation (rTMS) in treating post-stroke aphasia with a goal to identify parameters that are associated with successful treatment outcomes. Methods: Following PRISMA guidelines, ten electronic databases were searched from inception till June 4th 2020. A total of 24 studies (out of 1971 records) with 567 participants met selection criteria and were included in the meta-analysis. Results: The overall pooled meta-analysis revealed a significant medium effect size in favor of rTMS treatment: Standard mean difference (SMD) of 0.655 (95% CI = [0.481, 0.830], z = 7.369, p < 0.001). Moderator subgroup analyses indicated that participants’ clinical characteristics and rTMS parameters moderated treatment effects. The strongest effects were observed for naming, followed by speech production, repetition and comprehension. The results indicate that with 10 to 15 sessions of 1-Hz rTMS administered 20–40 min per day over right BA45 (Brodmann's area 45), significant language improvements can be observed for up to 12 months. Conclusions: Our findings suggest that the rTMS technique can enhance rehabilitation of language skills in post-stroke aphasia when administered according to the established safety parameters. Significance: Our results have implications for treatment of post-stroke aphasia. In subacute aphasia, low frequency rTMS over right BA45 improved naming, repetition, speech fluency and writing but not comprehension, whereas in chronic aphasia naming and speech production improved, but repetition and comprehension showed smaller gains.