transcranial Direct Current Stimulation (tDCS) in the treatment of chronic tinnitus – results of a pilot study

Introduction: Chronic tinnitus is associated with an increased neuronal activity of central auditory pathways. For conscious perception you need additional co-activation of frontal and parietal areas (Boly et al. 2004). Correspondingly magnetencephalographic analyses show, that patients with chronic tinnitus present spacious alterations of neuronal networks (Schlee et al. 2008, Schlee et al. 2009). These areas could represent additional targets for a neuromodulatory therapy (Kleinjung et al. 2008). Here we examined the clinical effect of a modulation frontal areas with transcranial Direct Current Stimulation (tDCS) in patients with chronic tinnitus, who did not respond with repetitive Transcranial Magnetic Stimulation (rTMS). Method: 20 patients with chronic decompensated tinnitus had been treated. All received several standard treatments like cognitive behavioural therapy, hearing aids, masker, vasoactive substances, antidepressants and rTMS. We performed with a tDC-S Stimulator (eldith; neuroConn GmbH/Ilmenau) 6 sessions in a period of 3 weeks. The anode was placed right frontal, the cathode left frontal. In each session we stimulated 30 minutes with 1 mA with a ramp of 8 seconds at the beginning and at the end. The treatment-effects were registered with the Tinnitus Handicap Inventory (THI) and the Beck Depression Inventory (BDI). Results: There was a reduction of the tinnitus severity over the time. Depression scores remained unchanged. There were no severe side effects. Conclusion: These preliminary data suppose, that there might be a positive effect of the tDCS in tinnitus severity. There were no alterations in depressive symptoms. Further placebo controlled studies with larger cohorts are needed to evaluate the importance of tDCS in the treatment of chronic tinnitus.