Effectiveness of High-Frequency Repetitive Transcranial Magnetic Stimulation in Migraine A Systematic Review and Meta-analysis

Objective The aim of the study was to evaluate the effectiveness of repetitive transcranial magnetic stimulation in migraine measured by decrease in pain severity or attack frequency. Methods A search at the Cochrane Controlled Trials Register (CENTRAL), MEDLINE (via PubMed), Embase, CINAHL, Web of Science, and Scopus. The risk of systematic bias was rated by using the Cochrane domain-based quality assessment tool. A random-effects model was used. Results Of 434 identified records, 8 randomized control studies were included in the meta-synthesis. All have used a high-frequency repetitive transcranial magnetic stimulation targeting the left dorsolateral prefrontal cortex. The risk of systematic bias was low. The difference between repetitive transcranial magnetic stimulation and control groups in frequency of migraine days per month was 8.1 (95% confidence interval = 4.8-11.4) days in favor of repetitive transcranial magnetic stimulation. Respectively, for intensity of migraine pain (scaled from 0 to 100), this difference was 13.6 (95% confidence interval = 5.3-21.8) points in favor of repetitive transcranial magnetic stimulation. The heterogeneity was substantial with I-2 = 86%. Conclusions In chronic migraine, repetitive transcranial magnetic stimulation seems to have positive effects on both migraine pain severity and attack frequency compared with sham stimulation. Although the effect on pain intensity was probably clinically insignificant, repetitive transcranial magnetic stimulation reduced pain frequency by 8 days per month on average.