Vestibular evoked myogenic potentials in patients with idiopathic bilateral vestibulopathy. Report of three cases.

Idiopathic bilateral vestibulopathy (IBV) is an acquired bilateral peripheral vestibular disorder of unknown cause. Three patients diagnosed as IBV by neuro-otological examination were reported. They underwent vestibular evoked myogenic potential (VEMP) testing which reflects the functionality of the sacculo-collic pathway. As a result, 2 of the 3 patients showed bilateral absence of VEMPs and one showed unilateral absence. The VEMPs of the 3 patients revealed that IBV affects not only the superior but also the inferior vestibular nerve systems. As previously reported in the cases of vestibular neuritis, VEMP could be useful for classifying IBV according to the function of the inferior vestibular nerve.