Tinnitus perception in patients after vagal nerve stimulator implantation for epilepsy

Purpose: Vagal nerve stimulation in conjunction with sound therapy has been proposed as a treatment for subjective tinnitus. The purpose of this study is to retrospectively review the effect of VNS on perception of tinnitus in epilepsy patients. We explore the incidence of tinnitus and its perceived reduction in patients requiring implantation of VNS for medically refractory seizures. Materials and methods: A phone survey was conducted in adult patients with prior VNS implantation. A questionnaire including the visual analog scale (VAS) of tinnitus loudness was used to determine the presence and severity of tinnitus. Results: Out of the 56 patients who had completed the phone survey, 20 (35%) reported the presence of pre-operative tinnitus. The tinnitus positive group was significantly older (p = 0.019). Of the 20 pre-operative tinnitus positive patients, all patients continued to have tinnitus post-operatively. Four (20%) noted no changes in VAS of tinnitus loudness while 16 (80%) had at least a one-point decrease. The mean difference between pre- and post-operative VAS of loudness was 2.05, with a standard deviation of 1.84 and this was statistically significant (p < 0.001). Conclusions: In this study, we evaluate the potential of vagal nerve stimulation to alter the perception of tinnitus in patients with refractory epilepsy. Eighty percent of patients noted some level of subjective tinnitus improvement after VNS implantation. Given this finding, there may be a potential additional benefit to the use of VNS in patients with epilepsy.