Impact of Combined Bifrontal Transcranial Direct-Current Stimulation and Conflict Processing Training on Tinnitus: a Protocol for Single-Blind Randomized Controlled Trial

The deficit in cognitive functions and central executive function is one of the popular hypotheses on the underlying cause of tinnitus. These factors are not only the complications of tinnitus but are also involved in the generation of it. In this study, bifrontal transcranial Direct Current Stimulation (tDCS) and conflict processing will be used in the form of auditory Stroop training to improve cognitive performance and inhibition control for tinnitus management.

This study will be carried out on 34 chronic tinnitus patients. The initial evaluations include the tinnitus psychoacoustic evaluations, determination of the tinnitus handicap through tinnitus handicap inventory, and examining the annoyance and loudness of tinnitus through the visual analog scale after which the participants will be investigated in two groups. The first group will receive sessions of tDCS followed by six sessions of conflict processing training. The second group will first receive tDCS in the form of sham, to be followed by six sessions of auditory Stroop. The evaluations will be repeated after each intervention.

Studies have shown that successive sessions of conflict processing training can enhance cognitive plasticity and inhibition function. As conflict processing training has not been addressed as rehabilitation training in the people suffering from tinnitus, these processes will be designed in four tasks as rehabilitation exercises in Farsi language and applied along with tDCS to the people with chronic tinnitus to decrease and control tinnitus by improving cognitive and inhibition control.
Trial registration: Iranian Registry of Clinical Trials (IRCT20120215009014N366) on Sep 17th, 2020.