Vestibular Testing to Predict the Nerve of Origin of Vestibular Schwannomas
Vestibular schwannomas (VS) mainly arise from either the superior (SVN) or the inferior vestibular nerve (IVN). Preoperative vestibular testing in patients affected by VS can be useful to predict which one of the vestibular nerves the tumor arises from. The relevance of identifying the nerve of origin lies in its prognostic factor for hearing preservation after surgery, with tumors arising from the (SVN) having a much higher hearing preservation rate. Diverse studies in the literature have tested the correlation between abnormal vestibular testing results and the nerve of origin of VSs; the techniques experimented in such context are posturography, vestibular evoked myogenic potentials (VEMPs), caloric test (always in combination with VEMPs), and video head impulse test (vHIT). vHIT has yielded promising results, with a positive predictive value ranging from 89.5 to 100%, so that the pattern of semicircular canal dysfunction on vHIT has been proposed to have a localizing value to identify the nerve of origin in VSs.
KeywordsVestibular schwannoma/vestibular nerve Vestibular schwannoma/vestibular testing Vestibular schwannoma/posturography Vestibular schwannoma/VEMPs Vestibular schwannoma/head impulse test
- 11.Constanzo F, Sens P, Teixeira BC de A, Ramina R. Video head impulse test to preoperatively identify the nerve of origin of vestibular schwannomas. Oper Neurosurg. 2018. https://doi.org/10.1093/ons/opy103.