Vestibular Evoked Myogenic Potential

Loud click or tone burst sound can activate vestibular receptor and evoke reflex changes in tonic electromyographic activity within the stenocleidomastoid muscles. This reflex is assumed to originate in the saccule, the afferent pathways being the inferior vestibular nerve, and the efferent pathways the vestibulospinal tract. Averaging these muscular responses allows vestibular evoked myogenic potentials (VEMP) to be obtained. The earliest response ipsilateral to a loud click, p13n23, is dependent upon vestibular activation, specifically saccular afferents. These new techniques are beginning to be applied clinically in the patient of vestibular neuritis, Meniere’ s disease, acoustic neuromas, Tullio phe nomenon, etc. VEMP recording will provide both a straightforward non-invasive exploration of each vestibule indepen dently and an attractive method by which to explore otolithic receptors and vestibulospinal pathways.