Vestibular evoked myogenic potentials in multiple sclerosis

ABSTRACT

Vestibular evoked myogenic potential [VEMP] is an otolith-mediated, short-latency reflex recorded from the sternocleidomostoid muscle in response to intense auditory clicks used for evaluation of the vestibulo-spinal pathway. This study aimed at shedding light on the sensitivity of VEMPs in detection of occult vestibular pathway lesions in patients suffering from multiple sclerosis [MS]. VEMPs were recorded from 25 MS patients. Clinical data were evaluated for possible brain stem affection, their EDSS scores were recorded. All patients underwent visual evoked potential [VEP], brainstem auditory evoked potential [BAEP], somatosensory evoked potential [SSEP] studies and magnetic resonance imaging [MRI]. VEMPs were also recorded in 25 age and sex matched controls as well. VEMPs showed abnormal P13 and N23 waves in 56% of Patients, VEP in 56%, BAEPs in 44%, SSEPs in 28% and MRI in 80%. MRI showed better sensitivity in detecting brain stem plaques yet patients with normal MRI had abnormal VEMPs and BAEPs and VEMPs had nearly equal sensitivity in detecting brainstem plaques in symptomatizing group; however VEMPs were more sensitive than BAEPs in non symptomatizing group. Also we found no significant correlation between VEMPs and MRI or BAEPs. VEMPs is a simple, non-invasive, safe and quick method, which should be considered as a complementary neurophysiological tool for evaluation of possible brainstem dysfunction