Paired vagus nerve and auditory stimulation for the treatment of tinnitus

IntroductionTinnitus is the presence of sound in the absence of an external sound source, which is associated with suffering in tinnitus disorder and affects quality of life worldwide. Vagus nerve stimula- tion (VNS) paired with non-tinnitus sounds has shown promise in reverting the tonotopic map changes seen in tinnitus. An alternative approach is to pair a replica of the tinnitus sound with VNS in order to associate it with the parasympathetic rest-and-digest response via Pavlovian conditioning. As the parasympathetic response may occur 5 seconds after VNS, the auditory stimulation (AS) could also be presented 5 seconds after VNS. This study aimed to evaluate the safety and feasibility of a novel paired non-invasive VNS and tinnitus-matched sound bimodal stimulation, and to explore whether activity and functional connectivity would be altered within tinnitus networks and the associated effects on clinical outcomes.