NF2-Related Intravestibular Schwannomas: Long-Term Outcomes of Cochlear Implantation

Objective: Intravestibular schwannomas (IVS) are uncommon tumors in Neurofibromatosis type 2 (NF2) and are mainly associated with multiple internal auditory meatus (IAM) and cerebellopontine angle (CPA) tumors. They usually induce profound hearing loss which can be rehabilitated by cochlear implantation (CI). The aim of this study was to analyze the long-term outcomes of CI during the unpredictable evolution of NF2 disease. Study Design: Retrospective case review. Setting: Tertiary referral center. Patients: Three adults with neurofibromatosis type 2 and intravestibular schwannomas, and who were cochlear implant recipients. Interventions: Periodic radiologic follow-up, tumor resection, and hearing rehabilitation. Main Outcome Measures: Audiological evolution, tumor evolution, surgical outcome, cochlear implant outcome. Results: Three NF2 patients (mean age at diagnosis, 26.3 +/- 3.2 yr) were identified with IVS in the period between 2000 and 2017. IVS were first observed by serial MRI and profound hearing loss occurred in this ear after 4 +/- 1.5 years of follow-up. IVS were removed via a translabyrinthine approach, and ipsilateral cochlear implantations were simultaneously performed. In two patients, large contralateral CPA tumors had previously been removed without hearing preservation, whereas in the third patient, a small, growing contralateral VS was excised via a retrosigmoid approach 6 months after IVS removal/cochlear implantation with serviceable hearing preservation. In all cases, CI provided good hearing outcomes. In two cases, hearing outcomes were even better for more than 5 years when ipsilateral intracanalicular vestibular schwannomas were removed in either the same or subsequent procedures. Conclusions: Rehabilitation of hearing with CI provides a favorable long-term outcome in patients with NF2-related IVS which could be altered by the occurrence of other intracanalicular and/or CPA NF2-related tumors.