Preoperative determination of nerve of origin in patients with vestibular schwannoma
18. April 2018 (online)
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 operative decision-making and planning. The aim of this study was to assess a novel scoring system that was designed to predict the nerve of origin.
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.
In 85% of cases, the preoperatively predicted tumor origin was the same as the origin determined during surgery. The remaining 15% showed an indifferent or wrong prediction. Thus, the overall classification accuracy was 85%.
Our present data suggest that the novel scoring system shows promise for identifying the nerve of origin of VS. In this small-scale study, this scoring system could differentiate between the superior and inferior vestibular nerves. The agreement between the preoperative and intraoperative findings suggests that a larger prospective study is warranted.