Hearing Rehabilitation with Cochlear Implants after CyberKnife Radiosurgery of Vestibular Schwannoma: A Report Based on Four Clinical Cases.

Markus Kufeld,Franziska Löbel,Sophia M Häußler,Heidi Olze,Agnieszka J Szczepek,Carolin Senger,Stefan Gräbel

doi:10.3390/brainsci11121646

Abstract

Severe sensorineural hearing loss can be a symptom of the benign tumor vestibular schwannoma (VS). The treatment of VS with non-invasive stereotactic radiosurgery (SRS) offers a high local tumor control rate and an innovative possibility of sequential hearing rehabilitation with cochlear implantation. This study evaluated the feasibility, complications, and auditory outcomes of such a therapeutic approach. Three males and one female (mean age 65.3 ± 9.4 years) scheduled for cochlear implantation and diagnosed with sporadic VS classified as T1 or T2 (according to Samii) were enrolled in this study. All patients had progressive hearing loss qualifying them for cochlear implantation. First, the tumor was treated using CyberKnife SRS. Next, sequential auditory rehabilitation with a cochlear implant (CI) was performed. Clinical outcomes and surgical feasibility were analyzed, and audiological results were evaluated using pure tone audiometry and speech recognition tests. All patients exhibited open-set speech understanding. The mean word recognition score (at 65 dB SPL, Freiburg Monosyllabic Test, FMT) improved after cochlear implantation in all four patients from 5.0 ± 10% (with hearing aid) preoperatively to 60.0 ± 22.7% six months postoperatively. Our results suggest that in patients with profound hearing loss caused by sporadic vestibular schwannoma, the tumor removal with SRS followed by cochlear implantation is an effective method of auditory rehabilitation.

Highlights

Vestibular schwannoma (VS) can induce profound hearing loss or deafness, a condition qualifying the patients for cochlear implantation
Intralabyrinthine schwannoma (ILS) and vestibular schwannoma (VS) are increasingly detected with cranial magnetic resonance imaging [4,5]
Patients # 1–3 were incidentally diagnosed with VS during pre-implantation diagnostics

Summary

Introduction

Vestibular schwannoma (VS) can induce profound hearing loss or deafness, a condition qualifying the patients for cochlear implantation. VS are benign neoplasms originating from Schwann cells surrounding the 8th cranial nerve as a myelin sheath [1]. The overall incidence of VS in the general population is about 1.7–4.2 per 100,000 [2,3]. Schwannomas can develop intracanalicularly (IC), in the cistern of the cerebellopontine angle (CPA), or intralabyrinthine. Intralabyrinthine schwannoma (ILS) and VS are increasingly detected with cranial magnetic resonance imaging (cMRI) [4,5]. VS accounts for approximately 3.0–3.4% [6,7] of the causes of sudden SHL

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