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 1 Hz 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 (F₃ = 15.7, p < 0.0001), annoyance (F₃ = 8.8, p = 0.0002), distress (F₃ = 9.1, p = 0.0002) and THI scores (F₄ = 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.

Key Words:

• Tinnitus
• electric field navigated
• transcranial magnetic stimulation
• TMS
• therapy

Acknowledgements

We thank Mr. Sami Sahlsten for his kind IT assistance.

Declaration of interest

Dr Sahlsten has received travel grant from Nexstim for an international congress on therapeutic use of rTMS. Dr Joutsa has received a lecturer honorarium from Boehringer-Ingelheim, travel grants from Abbvie and research grants from Lundbeck and the Orion Research Foundation. Dr Taiminen has received a lecturer honorarium from Astra-Zeneca, Bayer, Bristol-Myers Squibb, Efeko, Eisai, GlaxoSmithKline, Lilly, Lundbeck, Nexstim, Orion Pharma, Pfizer, Schering-Plough and UCB. PhD Holm has received a travel grant from ResMed. Prof Jääskeläinen has received a lecturer honorarium from Nexstim, Orion Pharma, Pfizer and Ratiopharm. Others involved in the study declared no conflicts of interest.

Funding

This study was supported by Finnish Governmental University Hospital grants (EVO), the Finnish Research Foundation of Ear Diseases, and State research funding from the Hospital District of Southwest Finland.

Supplementary material available online