Transcranial direct current stimulation in tinnitus rehabilitation: a case report

ABSTRACT

Tinnitus is an auditory perception without an external sound source. Transcranial direct current stimulation is a promising therapy for modulating the neurobiological substrates associated with this condition. This case report aimed to evaluate whether the discomfort and impact of tinnitus on patients' quality of life change after neuromodulation intervention. Adults with chronic tinnitus were included after otorhinolaryngological evaluation. The cases analyzed derive from a pilot study. The procedures included a speech-language-hearing history, pure-tone audiometry, high-frequency audiometry, pitch and loudness matching, a visual analog scale, and the Tinnitus Handicap Inventory. The intervention consisted of applying a 2-mA current for 20 min for 5 consecutive days, with an anodal electrode in the left temporoparietal area and a cathodal electrode in the right dorsolateral prefrontal cortex. The cases were expressed individually, and the data were analyzed descriptively. Five patients (three women and two men), with a mean age of 45 years, were evaluated. As to audiometry, six ears had normal hearing, while all ears had decreased high-frequency sensitivity. Scale scores decreased after five neuromodulation sessions; the mean score in the pre-therapy group decreased from 5.2 to 4.4 points post-therapy. The total questionnaire score decreased from 36.8 to 33.2 points. The mean loudness decreased from 10.4 to 9.2 dB SL. The results suggest that noninvasive neuromodulation reduced the annoyance and impact of tinnitus on these patients’ quality of life.

Keywords:
Tinnitus; Transcranial direct current stimulation; Electrical stimulation therapy; Rehabilitation; Hearing; Psychoacoustics