Vestibular Tests Related to Tumor Volume in 137 Patients With Small to Medium-Sized Vestibular Schwannoma

ObjectiveThe video head impulse test (vHIT) and cervical and ocular vestibular evoked myogenic potentials (cVEMP and oVEMP) are new methods for measuring peripheral vestibular function. The objectives of this study were to compare these tests and the traditionally used caloric test in patients with small and medium-sized untreated vestibular schwannoma (VS) and to measure the correlation between the tests' results and tumor volume. Study DesignNational cross-sectional study. SettingTertiary university clinic. MethodsPrevalence of abnormal cVEMP, oVEMP, caloric test, and 6-canal vHIT results on the tumor side and the nontumor side were compared and related to tumor volume with regression analyses in 137 consecutive VS patients assigned to a wait-and-scan protocol in the period 2017 to 2019. ResultsThe sensitivity of 6-canal vHIT, caloric test, cVEMP, and oVEMP to detect vestibulopathy in VS patients was 51%, 47%, 39%, and 25%, respectively. Normal tests were found in 21% of the patients. The results of vHIT and caloric test were related to tumor volume, but this was not found for cVEMP and oVEMP. ConclusionThe caloric test and 6-canal vHIT showed the highest sensitivity in detecting vestibulopathy in untreated VS patients. vHIT, and particularly the posterior canal, was limited with a high prevalence of abnormal results on the nontumor side. A combination of cVEMP and caloric test was favorable in terms of a relatively high sensitivity and low prevalence of abnormal results on the nontumor side. Larger tumors had a higher rate of pathology on caloric testing and vHIT.

Automated summary

This study compared the application of cervical and ocular vestibular evoked myogenic potentials (cVEMP and oVEMP), video head impulse test (vHIT), and the traditional caloric test in patients with untreated vestibular schwannoma (VS). The results showed that 6-canal vHIT and the caloric test had the highest sensitivity in detecting vestibulopathy in these patients.