Intraoperative Monitoring of the Cochlear Nerve during Neurofibromatosis Type-2 Vestibular Schwannoma Surgery and Description of a Test Intracochlear Electrode

摘要

>Objectives  A decision on whether to insert a cochlear implant can be made in neurofibromatosis 2 (NF2) if there is objective evidence of cochlear nerve (CN) function post vestibular schwannoma (VS) excision. We aimed to develop intraoperative CN monitoring to help in this decision. >Design  We describe the intraoperative monitoring of a patient with NF2 and our stimulating and recording set up. A novel test electrode is used to stimulate the CN electrically. >Setting  This study was set at a tertiary referral center for skull base pathology. >Main outcome measure  Preserved auditory brainstem responses leading to cochlear implantation. >Results  Electrical auditory brainstem response (EABR) waveforms will be displayed from different stages of the operation. A cochlear implant was inserted at the same sitting based on the EABR. >Conclusion Electrically evoked CN monitoring can provide objective evidence of CN function after VS excision and aid in the decision-making process of hearing rehabilitation in patients who will be rendered deaf.