Consecutive Dual-Session tDCS in Chronic Subjective Severe to Catastrophic Tinnitus With Normal Hearing

The device used for tDCS in this study was DC-Stimulator Plus (NeuroConn GmbH, Ilmenau, Germany). The localization of stimulation area (DLPFC) was determined according to the 10/20 EEG system. Non-conducting, elastic head strap was placed around the head to prevent displacement during stimulation. The recording electrode covered with 5 x 7 cm sized traditional rectangular sponge was soaked with 6-7 mL of 0.9% NaCl saline solution per side and placed on the F3 (anode, left frontal) and F4 (cathode, right frontal) EEG location. Subjects were given 2 mA stimulation intensity for 20 min per session including fade-in and fade-out times for 20 seconds each. Interval between each session was 20 min. Sham procedure has been adopted a Fade In of current, Short Stimulation, Fade Out (FISSFO) protocol that consist of initial ramp up for 20 seconds, 2 mA stimulation for 40 seconds, and 20 seconds for ramp down. To check to impendence, brief current of 110 µA over 15ms every 550ms was delivered.