[Preoperative determination of nerve of origin in patients with vestibular schwannoma. German version]

Abstract

Background: Vestibular schwannoma (VS) is a benign tumor that develops in the internal auditory canal and the cerebellopontine angle, potentially diminishing hearing or balance. Most VS tumors arise from one of two vestibular branches: the superior or inferior vestibular nerve. Determining the specific nerve of origin could improve patient management in terms of preoperative counseling, treatment selection, and surgical decision-making and planning. The aim of this study was to introduce a novel scoring system that was designed to determine the nerve of origin.

Methods: The nerve of origin was predicted based on video head impulse assessments of all semicircular channels, together with cervical/ocular vestibular-evoked myogenic potential tests. The acquired data were entered into a scoring system developed to allocate the tumor origin. Finally, the nerve of origin was definitively determined intraoperatively.

Results: The novel scoring system was applied to 5 consecutive patients undergoing surgical VS treatment. In one case, no determination was possible. In all other cases, the preoperatively predicted tumor origin was the same as the origin determined during surgery.

Conclusion: The scoring system predicts the nerve of origin and will be evaluated in a larger prospective cohort study of VS patients in the near future.

Keywords: Acoustic neuroma; Cranial nerve neoplasms; Head impulse test; Vestibular function tests; Vestibular nerve.