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

Abstract

Objective: Intravestibular schwannomas (IVSs) 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 longterm 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, 21 ± 2.5 years) were identified with IVS in the period between 2000 and 2014. 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 (TL) 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.

A new device for the removal of cochlear schwannoma: A temporal bone study

“…Intralabyrinthine schwannomas are tumors of the lateral skull base that can occur spontaneously or as part of an NFII ( 1 ). With the increasing number of patients with unilateral deafness implanted with a cochlear implant and thereforea mandatory MRI in most countries, the occurrence of ILS has received much attention since more cases are found.…”

“…Intra-labyrinthine schwannomas (ILSs) are rare tumors of the lateral skull base and can cause unilateral deafness and can occur in neurofibromatosis type II (NFII) ( 1 , 2 ). These tumors have been classified by Kennedy et al ( 3 ) according to their location.…”

Seltene Erkrankungen des vestibulären Labyrinths: von Zebras, Chamäleons und Wölfen im Schafspelz

“…Intracochlear schwannomas are the most frequent subtype making up for 50 % of all ILS. Bilateral tumors have been described in patients with neurofibromatosis type II [258] and sporadically [259].…”

“…50% die häufigste Gruppe der intralabyrinthären Schwannome dar. Bilaterale ILS wurden sowohl bei Patienten mit Neurofibromatose Typ II 258 als auch sporadisch beschrieben 259 .…”

Cochlear Implant Outcomes between Patients with Sporadic and Neurofibromatosis Type 2–Associated Vestibular Schwannoma

“…Several studies have shown success with cochlear implantation in this population, generally with improved outcomes compared with auditory brainstem implantation (2–6). Although studies are limited, some have also stratified CI outcomes according to treatment modality to inform treatment algorithms for VS with long-term hearing in mind (2–6).…”