Objectives Here we present the audiometric outcomes of patients
undergoing vestibular schwannoma resection and cochlear implantation. We
additionally reviewed preoperative audiometric and radiological data,
with the aim of developing a new scoring system to identify suitable
patients for this treatment course. Methods After translabyrinthine
vestibular schwannoma resection, cochlear nerve conduction was evaluated
using intraoperative electrically evoked brain stem response audiometry.
Patients with positive results received a cochlear implant. We evaluated
the preoperative audiometric results, and vestibular schwannoma size and
extension, to develop a new scoring system to identify patients with
higher likelihood of nerve integrity after tumor removal and subsequent
cochlear implantation. Results Seventeen patients with unilateral
sporadic vestibular schwannomas underwent translabyrinthine resection,
of whom ten received a cochlear implant. Ten patients are daily cochlear
implant users. The mean word recognition score ss 28% at 65 dB, and
52% at 80 dB. Nine of the ten patients have open-set speech
understanding. All patients whose vestibular schwannoma did not make
contact with the modiolus were able to receive a cochlear implant,
compared to none of the patients with modiolus infiltration. Tumor size
alone did not predict the probability of sparing the cochlear nerve.
Conclusions Simultaneous translabyrinthine vestibular schwannoma
excision and cochlear implantation based on intraoperative electrically
evoked brain stem response audiometry measurements is a good option for
hearing rehabilitation. Preoperative exact assessment of the vestibular
schwannoma extension, audiometric testing, and promontory stimulation
electrically evoked brain stem response audiometry could improve
preoperative patient selection and predict the possibility of cochlear
implantation.
Intraoperative Monitoring of the Cochlear Nerve during Neurofibromatosis Type-2 Vestibular Schwannoma Surgery and Description of a “Test Intracochlear Electrode”