Combined bifrontal transcranial direct current stimulation and tailor-made notched music training in chronic tinnitus

Background and Objectives: We evaluated the short-term treatment outcomes of combined bifrontal transcranial direct current stimulation (tDCS) and tailor-made notched music training (TMNMT) in tinnitus patients. The associations of patient characteristics with treatment responsiveness were investigated. Subjects and Methods: Four sessions of bifrontal tDCS (F4: anode, F3: cathode) and TMNMT were conducted over a 2-week period in tinnitus patients. For tDCS, the stimulation intensity was 1.5 mA and the duration was approximately 20 min. During tDCS, patients listened to music lacking the frequency band within 1 octave of the tinnitus frequency. Patients were also instructed to listen to this music at home for at least 2 hours per day. One month after the final tDCS session, loudness (LD), awareness (AW), annoyance (AN), and effect on life (EL) of tinnitus were assessed subjectively using a visual analog scale. Results: A total of 14 patients were enrolled in this study. After treatment, a 50% or greater improvement in AN, AW, EL, and LD was observed in 57.1, 42.9, 35.7, and 28.6% of patients, respectively. Furthermore, 78.6% of patients showed a 50% or greater improvement in their tinnitus handicap inventory scores. For AN, the absence of sleep disturbance was significantly associated with treatment responsiveness (p=0.041, OR=24.0). Conclusions: Combined bifrontal tDCS and TMNMT is a promising treatment for chronic tinnitus. To maximize the treatment outcomes of this therapy, sleep disturbances should also be addressed in candidate patients.