Electric field-navigated transcranial magnetic stimulation for chronic tinnitus: a randomized, placebo-controlled study

Abstract

Objective: Repetitive transcranial magnetic stimulation (rTMS) may alleviate tinnitus. We evaluated effects of electric field (E-field) navigated rTMS targeted according to tinnitus pitch. No controlled studies have investigated anatomically accurate E-field-rTMS for tinnitus. Design: Effects of E-field-rTMS were evaluated in a prospective randomised placebo-controlled 6-month follow-up study on parallel groups. Patients received 10 sessions of 1Hz rTMS or placebo targeted to the left auditory cortex corresponding to tonotopic representation of tinnitus pitch. Effects were evaluated immediately after treatment and at 1, 3 and 6 months. Primary outcome measures were visual analogue scores (VAS 0-100) for tinnitus intensity, annoyance and distress, and the Tinnitus Handicap Inventory (THI). Study sample: Thirty-nine patients (mean age 50.3 years). Results: The mean tinnitus intensity (F-3=15.7, p<0.0001), annoyance (F-3=8.8, p=0.0002), distress (F-3=9.1, p=0.0002) and THI scores (F-4=13.8, p<0.0001) decreased in both groups over time with non-significant differences between the groups. After active rTMS, 42% and 37% of the patients showed excellent response at 1 and 3 months against 15% and 10% in the placebo group (p=0.082 and p=0.065). Conclusions: Despite the significant effects of rTMS on tinnitus, differences between active and placebo groups remained non-significant, due to large placebo-effect and wide inter-individual variation.