Repetitive transcranial magnetic stimulation on chronic tinnitus: a systematic review and meta-analysis

BACKGROUND: Although the clinical efficacy and safety of repetitive transcranial magnetic stimulation (rTMS) in the treatment of chronic tinnitus have been frequently examined, the results remain contradictory. Therefore, we performed a systematic review and meta-analysed clinical trials examining the effects of rTMS to evaluate its clinical efficacy and safety. METHODS: Studies of rTMS for chronic tinnitus were retrieved from PubMed, Embase, and Cochrane Library through April 2020. Review Manager 5.3 software was employed for data synthesis, and Stata 13.0 software was used for analyses of publication bias and sensitivity. RESULTS: Twenty-nine randomized studies involving 1228 chronic tinnitus patients were included. Compared with sham-rTMS, rTMS exhibited significant improvements in the tinnitus handicap inventory (THI) scores at 1 week (mean difference [MD]: − 7.92, 95% confidence interval [CI]: − 14.18, − 1.66), 1 month (MD: -8.52, 95% CI: − 12.49, − 4.55), and 6 months (MD: -6.53, 95% CI: − 11.406, − 1.66) post intervention; there were significant mean changes in THI scores at 1 month (MD: -14.86, 95% CI: − 21.42, − 8.29) and 6 months (MD: -16.37, 95% CI: − 20.64, − 12.11) post intervention, and the tinnitus questionnaire (TQ) score at 1 week post intervention (MD: -8.54, 95% CI: − 15.56, − 1.52). Nonsignificant efficacy of rTMS was found regarding the THI score 2 weeks post intervention (MD: -1.51, 95% CI: − 13.42, − 10.40); the mean change in TQ scores 1 month post intervention (MD: -3.67, 95% CI: − 8.56, 1.22); TQ scores 1 (MD: -8.97, 95% CI: − 20.41, 2.48) and 6 months (MD: -7.02, 95% CI: − 18.18, 4.13) post intervention; and adverse events (odds ratios [OR]: 1.11, 95% CI: 0.51, 2.42). Egger’s and Begg’s tests indicated no publication bias (P = 0.925). CONCLUSION: This meta-analysis demonstrated that rTMS is effective for chronic tinnitus; however, its safety needs more validation. Restrained by the insufficient number of included studies and the small sample size, more large randomized double-blind multi-centre trials are needed for further verification.