Vestibular Evoked Myogenic Potential in Meniere's Syndrome

ABSTRACT

BACKGROUND: Acoustic stimulation of the saccule can evoke the vestibulocolic reflex and the inhibitory potential can be measured in the ipsilateral sternocleidomastoideus as a vestibular evoked myogenic potential (VEMP). We investigated the saccular dysfunction in patients with Meniere's syndrome by using VEMP, and correlated the findings with those of other vestibular function tests. METHODS: Thirty-six patients, 29 with Meniere's disease and 7 with delayed endolymphatic hydrops, underwent interictal VEMP. Eight patients reported Tumarkins otolithic crisis. The patients also had a bithermal caloric test, testing of the subjective visual vertical (SVV), and brainstem auditory evoked potentials (BAEP) in addition to pure tone and speech audiometry. RESULTS: Abnormal VEMP was observed in 21 (58.3%) patients. All the patients with abnormal VEMP showed decreased amplitude or absence of VEMP in the lesion side. Three of them also exhibited delayed p13 or n23 latency. The VEMP was abnormal in four of the 13 patients with normal calorics, 13 of the 21 with normal SVV, and 11 of the 21 with normal BAEP. The abnormal VEMP was more common in patients with delayed endolymphatic hydrops (71.4%) and Tumarkins otolithic crisis (75.0%), but without statistical significance. CONCLUSIONS: VEMP detects saccular dysfunction in Meniere's syndrome. The abnormal VEMP in some patients with normal calorics, SVV or BAEP suggests differential involvement of the vestibular subsystem in Menieres syndrome especially in the early stage.