Treatment of chronic tinnitus with θ burst stimulation: a randomized controlled trial

To test whether 4 weeks of bilateral repetitive transcranial magnetic stimulation (rTMS) to the temporal or temporoparietal cortex is effective and safe in the treatment of chronic tinnitus.

In this controlled 3-armed trial, 48 patients with chronic tinnitus were treated with 4 weeks (20 sessions) of bilateral continuous theta burst stimulation (cTBS) at the Tübingen University Hospital. They were randomized to stimulation above the temporal cortex, the temporoparietal cortex, or as sham condition behind the mastoid. Patients were masked for the stimulation condition. Tinnitus severity was assessed after 2 and primarily 4 weeks of treatment and at 3 months follow-up with the tinnitus questionnaire and by a tinnitus change score. Audiologic safety was monitored by pure-tone and speech audiometry after 2 and 4 weeks of cTBS.

Tinnitus severity was slightly reduced from baseline by a mean (SD) 2.6 (8.2) after sham, 2.4 (8.0) after temporoparietal, 2.2 (8.3) after temporal treatment of 16 patients each, but there was no significant difference between sham treatments and temporal (confidence interval [CI] -5.4 to +6.7) or temporoparietal cTBS (CI -5.9 to +6.3) or real cTBS (CI -7 to +5.1). Patients' global evaluation of tinnitus change after treatment did not indicate any effects. Audiologic measures were unaffected by treatment.

Treating chronic tinnitus for 4 weeks by applying cTBS to the temporal or temporoparietal cortex of both hemispheres appears to be safe but not more effective than sham stimulation. However, these results are not to be generalized to all forms of rTMS treatments for tinnitus.