Consecutive Dual-Session Transcranial Direct Current Stimulation in Chronic Subjective Severe to Catastrophic Tinnitus with Normal Hearing

Abstract

Transcranial direct current stimulation (tDCS) is emerging as a promising non-invasive intervention for tinnitus by aiming to modulate abnormal brain activity. This study investigated the efficacy of dual-session tDCS for the relief of perception, distress, and loudness in patients with severe chronic subjective tinnitus and assessed the duration of tinnitus suppression effects compared to single-session and control groups over a 2-month follow-up. In a prospective, randomized, single-blind, placebo-controlled trial, 30 participants with severe chronic subjective tinnitus underwent bifrontal tDCS. The control group (n = 9), single-session group (n = 10), and dual-session group (n = 11) received 2 mA stimulation for 20 min per session, twice a week for one month. The treatment response was monitored weekly using the Visual Analogue Scale (VAS), with additional assessments using the Tinnitus Handicap Inventory (THI) and Beck Depression Inventory (BDI) at the fourth and eighth weeks. The single- and dual-session groups showed statistically significant improvements in VAS, THI, and BDI scores compared to the control group. THI and BDI scores showed a significant difference between the single- and dual-session groups. The dual-session group demonstrated a more sustained tinnitus suppression effect than the single-session group. tDCS has been validated as an effective intervention for the suppression of tinnitus, with the dual-session protocol showing longer-term benefits. These findings support the potential of tDCS as a treatment for tinnitus, particularly in dual-session applications.