Surgical approaches to tinnitus treatment: A review and novel approaches

Abstract

Background: Tinnitus, a profoundly widespread auditory disorder, is characterized by the perception of sound in the absence of external stimulation. The aim of this work is to review the various surgical treatment options for tinnitus, targeting the various disruption sites along the auditory pathway, as well as to indicate novel neuromodulatory techniques as a mode of tinnitus control.

Methods: A comprehensive analysis was conducted on published clinical and basic neuroscience research examining the pathophysiology and treatment options of tinnitus.

Results: Stereotactic radiosurgery methods and microvascular decompressions are indicated for tinnitus caused by underlying pathologies such as vestibular schwannomas or neurovascular conflicts of the vestibulocochlear nerve at the level of the brainstem. However, subsequent hearing loss and secondary tinnitus may occur. In patients with subjective tinnitus and concomitant sensorineural hearing loss, cochlear implantation is indicated. Surgical ablation of the cochlea, vestibulocochlear nerve, or dorsal cochlear nucleus, though previously suggested in earlier literature as viable treatment options for tinnitus, has been shown to be ineffective and contraindicated. Recently, emerging research has shown the neuromodulatory capacity of the somatosensory system at the level of the trigeminal nerve on the auditory pathway through its inputs at various nuclei in the central auditory pathway.

Conclusion: Tinnitus remains to be a difficult disorder to treat despite the many surgical interventions aimed at eliminating the aberrant neuronal activity in the auditory system. A promising novel neuromodulatory approach using the trigeminal system to control such a bothersome and difficult-to-treat disorder deserves further investigation and controlled clinical trials.

Keywords: Cochlear implant; Tinnitus; microvascular decompression; neuromodulation; stereotactic radiosurgery/stereotactic radiotherapy; trigeminal nerve; trigeminal nerve stimulation.

Figure 1

Flowchart illustrating tinnitus treatment options – Figure 1 demonstrates the categorization of tinnitus type and the subsequent diagnostic and surgical treatment options based upon the origin of tinnitus symptomatology

Figure 2

(A-H): Photomicrographs of rat mossy fibers showing mossy fibers from the spinal trigeminal nucleus are found restricted to the Granule Cell Domain (GCD). Tracings from the Spinal Trigeminal Nucleus projections to Ventral and Dorsal Cochlear Nuclei – Figure 2 illustrates the somatosensory inputs of the trigeminal nerve at the level of the Spinal Trigeminal Nucleus on the cochlear nuclei. This illustration shows the nuclei communication, offering the anatomical and physiological basis for stimulation of the trigeminal system as a possible therapeutic option for tinnitus. Each tick mark represents a trigeminal neuronal terminal ending