Surgical Neuromodulation of Tinnitus: A Review of Current Therapies and Future Applications.

INTRODUCTION: Tinnitus is the conscious perception of an auditory sensation in the absence of external stimulus. Proposed theories are based on neuroplastic changes that occur due to sensory deprivation. The authors review the relevant literature on functional imaging and neuromodulation of tinnitus and describe potential targets for deep brain stimulation (DBS). MATERIALS AND METHODS: A MEDLINE keyword and Medical Subject Heading term literature search was performed using PubMed for tinnitus, neuromodulation, DBS, transcranial magnetic stimulation, epidural electrode stimulation, intradural electrode stimulation, functional imaging, and connectivity. Data from these reports were extracted and reviewed. RESULTS: Multiple imaging studies are employed to understand the pathophysiology of tinnitus. Abnormal regions and altered connectivity implicated in tinnitus include auditory pathway and limbic structures. Neuromodulation attempts to correct this hyperexcitable state by disrupting these aberrant oscillations and returning activity to baseline. Applied treatment modalities include transcranial magnetic stimulation, epidural/intradural electrode stimulation, and DBS. More recently, modulation of autonomic pathways through vagus nerve stimulation and paired auditory sounds has demonstrated tinnitus improvement via plasticity changes. CONCLUSIONS: DBS shows much promise as a therapeutic option for tinnitus. Stimulation of the auditory pathway, particularly the medial geniculate body, could counteract thalamocortical dysrhythmias and reduce gamma activity implicated in the tinnitus percept. Stimulation of the limbic pathway could decrease attention to and perception of tinnitus. Additional studies, focusing on the involvement of thalamic and limbic structures in the pathophysiology of tinnitus, are needed to support the use of DBS.

Concurrent Placement of Bilateral Suboccipital and Supraorbital Nerve Stimulators Using On-Q* Tunneler: Technical Note.

BACKGROUND: Stimulation of the occipital and supraorbital nerves is used to treat chronic migraine refractory to medical management. Placement of cranial leads is often challenging due to the rigid Touhy needle included in the kit for its placement. OBJECTIVE: To report the first case of concurrent placement of bilateral supraorbital (SNS) and occipital nerve stimulators (ONS) from a unilateral approach using the On-Q* Tunneler, (Halyard Health, Alpharetta, Georgia) a flexible, blunt tipped plastic tunneler with a tear-away sheath. METHODS: We present the case of a 49-yr-old female with debilitating daily holocephalic headaches who underwent placement of SNS and ONS through a cervical and left temporal incision at an outside hospital. She presented to our institution with purulent drainage from the temporal incision and the system was removed. We describe an alternative approach to bilateral SNS and ONS placement with a soft flexible tunneling device, which facilitated placement of the entire system through a right temporal incision, thereby avoiding her previously infected surgical sites. RESULTS: The patient reported complete resolution of her daily headaches and was able to resume her activities as a full-time student. CONCLUSION: The flexibility of the On-Q tunneler device (Halyard Health) allows the placement of bilateral SNS and ONS from a unilateral incision, thereby minimizing the cosmetic effect and infectious risk of this procedure.