Vestibular Evoked Myogenic Potentials (VEMP) is a useful test because the results can provide unique information about the otoliths (saccule and utricle), the inferior vestibular nerve, and the central pathways (intact and working properly). ENG/VNG’s calorics only evaluate the horizontal semicircular canal and the pathway through the superior portion while VEMPs evaluate the saccule (and utricle and superior vestibular nerve if using oVemps) and the inferior portion of the vestibular nerve. VEMPs can be useful supplementary information along with other vestibular assessments to find out what the etiology of the disorder might be. For instance, if a patient has abnormal calorics and a normal VEMP, then there is a focal lesion (horizontal …show more content…
This indicates that the person’s saccule and IV nerve are functioning normally (Vestibular Evoked Myogenic Potential). With a VEMP in a normal patient, one would get responses that show the positive peak (P1) around 13 milliseconds followed by the negative peak or N1 at around 23 milliseconds. The amplitude difference should also show a ratio of less than or equal to 40% when the tonic EMG of the SCD is activated properly (Vestibular Evoked Myogenic Potential).

4. What VEMP results would you expect to see in a patient with Meniere's Disease?

With Meniere’s Disease the findings can vary by the stage and the acuteness of the disease. Fifty percent of the patients that have the disease will show an asymmetric cVEMP which reveals the differences in the saccule’s function. If the asymmetry ratio is increased (greater than 40%), then this finding is prevalent in Meniere’s Disease (hydrops). VEMPs can also be absent. When the saccule is dysfunctional and/or the 8th nerve on the ipsilateral side isn’t working (as in Meniere’s disease), then the thresholds are either elevated or absent. The amplitude of the response can either be reduced or normal. Latency is normal. The VEMP responses can also be enhanced with Meniere’s Disease