A novel scoring system for vestibular schwannomas to identify candidacy for cochlear implantation

Abstract

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.