Intraoperative electrically auditory brainstem responses to monitor auditory functionality preservation during auditory brainstem implant application.

Background: Perceptual outcomes of individuals with neurofibromatosis type II implanted with auditory brainstem implant are poor, and many factors seem to be involved. Undoubtedly, the preservation of neural functionality is the crucial aspect. The aim of this study is to verify that the use of intraoperative electrically auditory brainstem responses can help to understand if there is neural damage related to the tumor, and / or surgery. Material and Methods: A retrospective case series analysis was performed to review data from 6 adult patients affected by neurofibromatosis type 2 who received an auditory brainstem implant. A correlation was sought between intraoperative electrophysiological data, auditory performance at 1 and 2.5 years of follow-up, and auditory brainstem implant stimulation levels. Results: Patients with a better perceptual outcomes were those with more intraoperative peaks and peaks with wider amplitudes in the electrically auditory brainstem response recordings. Conclusions: Electrically auditory brainstem responses used for auditory brainstem implant placement can be a valuable tool for monitoring the preservation of neural acoustic functionality.