An animal model of deep brain stimulation for treating tinnitus: A proof of concept study.

Abstract

This proof-of-concept study aimed to demonstrate therapeutic effects of deep brain stimulation (DBS) on noise-induced tinnitus. Experimental animal study. After Institutional Animal Care and Use Committee approval, nine adult rats were implanted in the caudate nucleus with custom-made electrode array. The rats were exposed to noise to induce tinnitus. Auditory brainstem response was performed to evaluate hearing threshold changes. Noise-induced tinnitus and its suppression by DBS were evaluated using the gap-detection acoustic startle reflex behavioral paradigm and electrophysiological evaluation of modulatory effects on neural correlates of tinnitus. Various stimulation parameters were used to determine the most effective ones in affecting behavioral changes, along with corresponding neural activity in the caudate nucleus. The correlation between the caudate nucleus and auditory cortex also was determined. Analysis of variance with Bonferroni correction was performed to examine DBS-induced effects on behavioral evidence of tinnitus. Bursting activity, a neural marker of tinnitus, was noted to decrease compared to baseline in tinnitus (+) animals. After stimulation, spontaneous and bursting activity increased in the tinnitus (+) animals but decreased in the tinnitus (-) animals. Behavioral data suggested suppression of tinnitus after DBS. These effects lasted up to 5 days. To our knowledge, this is the first development of an animal model to test deep brain stimulation of the caudate region for the treatment of tinnitus. Deep brain stimulation of the caudate nucleus can modulate tinnitus in a rat model of tinnitus. NA. Laryngoscope, 128:1213-1222, 2018.