Chronic tinnitus is a frequent disease accompanied in many cases by high morbidity and reduction in quality of life. Despite its high incidence, treatment remains elusive. Aggregated research over the last years has contributed to a deeper understanding of the neurobiological basis of chronic tinnitus and point to the involvement of auditory and non-auditory brain areas. Repetitive transcranial magnetic stimulation (rTMS) is able to non-invasively modulate brain activity. Pilot studies indicate a potential therapeutic effect of rTMS in tinnitus patients, however, sample sizes were small so far. The aim of this study was to evaluate the efficacy and safety of rTMS in tinnitus in a large patient sample.
Methods
7 study centers participated in this randomized, placebo-controlled trial. From February 2008 until May 2011 a total of 154 patients were enrolled and received 10 sessions of either verum or sham 1 Hz-rTMS over the left primary auditory cortex. Effects on tinnitus and accompanying psychiatric symptoms were evaluated using a variety of standardized rating scales (tinnitus questionnaire (TQ), tinnitus handicap inventory (THI), beck depression inventory, etc.).
Results and conclusions
rTMS treatment was well tolerated in all patients. In the primary outcome (change of the TQ-score baseline vs. day 12) no significant difference between both study arms was observed. During the follow-up period, a trend to superiority of verum rTMS could be observed, which did not reach statistical significance. This study shows, that 1 Hz-rTMS over the left primary auditory cortex is not superior to placebo treatment. Therefore, more effective treatment protocols are needed and combined treatment regimes focusing on auditory and non-auditory brain regions may be better as recent studies have demonstrated.
