Deep brain stimulation of the medial geniculate body for refractory tinnitus: A feasibility study

Tinnitus disorder can have a significant negative impact on quality of life, especially when refractory to standard care. Deep brain stimulation (DBS) of the medial geniculate body (MGB) attenuates pathological neuronal activity in the central auditory pathway and is a potential treatment for severe tinnitus. The aim of this pilot study was to assess the safety and feasibility of bilateral MGB DBS in patients with refractory tinnitus disorder. This randomised double-blind 2 ​× ​2 cross-over study was conducted at Maastricht University Medical Centre, Maastricht, the Netherlands. The included patients had treatment refractory, severe, and chronic tinnitus without an anatomical substrate. Patients with bilateral MGB DBS were randomised to an ON-OFF or OFF-ON stimulation order for two cross-over phases. Primary outcomes consisted of safety and feasibility. Secondary outcomes on tinnitus severity, psychiatric and cognitive functioning and quality of life were assessed at screening, after both cross-over phases and at one-year follow-up. Four patients were included. No irreversible stimulation-induced side effects were observed. Surgical-related side effects were transient and resolved within two weeks. All patients experienced DBS as an acceptable treatment. Three of four patients showed improvement of tinnitus complaints based on the Tinnitus Functional Index. In the non-responder, electrodes had the largest distance from the centre of the MGB. To conclude, this study shows that bilateral MGB DBS is safe and feasible for patients with refractory tinnitus. Findings suggest the potential for clinically meaningful reduction in tinnitus burden through DBS. Effectiveness needs to be further evaluated in a follow-up study.