Hearing Preservation

Abstract

Hearing preservation in vestibular schwannoma surgery is most influenced by the selection of eligible patients: middle fossa or retrosigmoid approaches may be attempted in patients with small tumor size (<1.5–2 cm) and good preoperative hearing. As regards the sole hearing outcome, the apparent advantages of less invasive options (wait and watch, radiotherapy) may be in reality problematic in the long term: the amount of sequelae is not inferior to those produced by primary hearing preservation surgery, and for this reason surgery should be attempted in every case of preoperative serviceable hearing. Intraoperative cochlear nerve monitoring should be used when hearing preservation is attempted; in respect of the preferable technique, there is still insufficient evidence to conclude whether direct monitoring of the eighth cranial nerve is superior to the use of far-field ABRs. LS-CE-Chirp® ABR represents a recent development of classical ABR. Acoustic energy from the LS-CE-Chirp® stimulus reaches all regions of the cochlea at approximately the same time, thus yielding enhanced neural synchronicity and faster detection of larger amplitude wave V.