Comparative analysis of audiovestibular testing results in vestibular schwannomas

Abstract

Objective:This study aimed to analyze the results of auditory and vestibular function tests in patients with unilateral vestibular schwannoma and explore their association with tumor size. Methods:Clinical data from 81 patients diagnosed with unilateral vestibular schwannoma who underwent pure-tone audiometry（PTA）, cervical and ocular vestibular evoked myogenic potentials（c/oVEMP）, as well as video head impulse test（vHIT）, and subsequently underwent surgical treatment, were retrospectively analyzed. Patients were categorized into groups based on tumor size: small （≤ 15 mm）, medium（16-30 mm）, and large （>30 mm）, determined by the maximum tumor diameter on contrast-enhanced MRI scans. Results:PTA results indicated hearing loss in 73 cases（90.1%）; vestibular function tests revealed abnormal rates for the anterior semicircular canal, horizontal semicircular canal, posterior semicircular canal, utricle, and saccule at 29.6%, 77.8%, 54.3%, 90.1%, and 92.6%, respectively. Statistically, no significant differences were found in preoperative hearing test results among patients in different groups（F=0.393, P=0.676）. However, significant differences were observed in horizontal semicircular canal gain（r=-0.248, P=0.025）, abnormal rates of horizontal semicircular canal catch-up saccades（r=0.507, P<0.001）, as well as cVEMP（χ²=15.111, P=0.004） and oVEMP thresholds（χ²=18.948, P<0.001） across varying tumor size groups. Conclusion:The extent of hearing loss in patients with vestibular schwannoma is not correlated with tumor size, whereas the degree of vestibular dysfunction demonstrates a correlation with tumor size.