Management of Vestibular Dysfunction and Hearing Loss in Intralabyrinthine Schwannomas

Introduction: Intralabyrinthine schwannomas (ILSs) are benign tumors arising from Schwann cells of the cochlear or vestibular nerves within the bony labyrinth. Due to the insidious onset of symptoms and subtle imaging findings, ILSs are often diagnosed months or years after symptom onset. Treatment options consist of observation with supportive care (vestibular or hearing rehabilitation), intratympanic gentamycin, stereotactic radiotherapy, or surgical excision.

Methods: After institutional review board approval, a retrospective chart review was performed of all ILS patients treated at our institution between 2007 and 2019 regarding demographics, symptoms, imaging, precise tumor location, and treatment decisions.

Results: A total of 20 patients (9 males, 11 females) with ILS were managed by our institution from 2007 to 2019. The right ear was affected in 9 patients (45%) and the left in 11 (55%). Sensorineural hearing loss was present in all 20 patients. Average pure tone at presentation was 72 dB NHL. ILS was intracochlear in six cases (30%), intravestibular in eight cases (40%), transmodiolar in two cases (10%), involved the vestibule and cochlea in one case (5%), and involved the middle ear, vestibule, cochlea, and internal auditory canal in three cases (15%). Hearing loss was treated in eight cases (40%). Hearing aids were used and effective in three cases (15%) and a bilateral contralateral routing of signal (BiCROS) device was used in two cases and effective in one (5%). A cochlear implant (CI) was placed and effective in two cases (10%), neither of which had intracochlear disease. One patient had limited audiology follow-up and ceased using the CI as he could hear well in the contralateral ear. The other patient continues to use the CI with significant benefit 2.5 years postimplantation. A bone-anchored hearing aid was placed in one case (5%). Vestibular rehabilitation was pursued in 5 of 12 patients with vestibular symptoms (42%). Surgical excision was performed in one case (5%) via translabyrinthine approach due to intractable vertigo in the setting of profound hearing loss, with resolution of vertiginous symptoms postoperatively. No patients received radiotherapy or intratympanic gentamicin injections.

Conclusion: ILS presents a diagnostic and management challenge given the similarity of symptoms with other disorders and limited treatment options. Hearing loss may be managed through noninvasive measures or cochlear implantation and vestibular loss may be mitigated with vestibular therapy. We recommend that surgical excision be reserved for patients with intractable vertigo and hearing loss be treated with appropriate measures.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
12 February 2021