Impact of Surgery on Long-Term Results of Hearing in Neurofibromatosis Type-2 Associated Vestibular Schwannomas.

Gugel Gugel,Kluwe Kluwe,Liebsch Liebsch,Grimm Grimm,Mautner Mautner,Tatagiba Tatagiba,Schuhmann Schuhmann,Zipfel Zipfel,Teuber Teuber

doi:10.3390/cancers11091376

Abstract

Hearing preservation is a major goal in the treatment of neurofibromatosis type 2 (NF2) associated vestibular schwannoma (VS), particularly in children and adolescents. In this study, we retrospectively reviewed hearing and volumetry data sets of 39 operated tumors (ears) in 23 patients under the age of 25 and in a follow-up period of 21 to 167 months. Hearing data over a compatible period on 20 other tumors, which did not receive surgery due to their less aggressive nature, were included for comparison. Surgery was carried out via a retrosigmoid approach with the brainstem auditory evoked potential (BAEP) guide. Immediately after surgery, functional hearing was maintained in 82% of ears. Average hearing scores were better in the non-surgery ears. However, the hearing scores in both groups worsened gradually with a similar dynamic during the 42-month postoperative follow-up period. No accelerated impairment of hearing was evident for the operated cases. Rather, the gap between the two hearing deterioration lines tended to close at the end of the follow-up period. Our result suggested that the BAEP-guided surgery did not cause additional hearing deterioration in the long-term and seemed to slow down hearing deterioration of those tumors that were initially more aggressive.

Highlights

Neurofibromatosis Type 2 (NF2) is a rare autosomal-dominant tumor predisposition syndrome, with a prevalence of 1:56,000, an incidence of 1 case in 33,000 to 40,000 live births per year [1,2].The disease is characterized by bilateral vestibular schwannomas (VS), other benign central or peripheral nervous system tumors and ocular, bone, and cutaneous manifestations [3,4,5,6]
Several strategies have been proven to be effective for neurofibromatosis type 2 (NF2)-associated VS—(1) partial resection mainly for decompression of the internal auditory canal and (2) electrophysiological guidance with brainstem auditory evoked potential (BAEP) and motor evoked potentials (MEP) of the facial nerve, by experienced interpreters [11,12,13]
We report a high postoperative functional hearing preservation rate of 82% after the BAEP guided surgery

Summary

Introduction

The disease is characterized by bilateral vestibular schwannomas (VS), other benign central or peripheral nervous system tumors (e.g., meningiomas, non-VS schwannomas, and spinal ependymomas) and ocular, bone, and cutaneous manifestations [3,4,5,6]. Due to the bilateral nature of VS in NF2 patients, hearing preservation is extremely important to prevent total deafness, especially for young patients. Several strategies have been proven to be effective for NF2-associated VS—(1) partial resection mainly for decompression of the internal auditory canal and (2) electrophysiological guidance with brainstem auditory evoked potential (BAEP) and motor evoked potentials (MEP) of the facial nerve, by experienced interpreters [11,12,13]

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Conclusion