Caloric testing and vestibular-evoked myogenic potentials (VEMP) are often abnormal in which conditions?

• A. Only in superior canal dehiscence.
• B. Only in vestibular migraine.
• C. None of the above.
• D. Both Menière disease and vestibular schwannoma.

Answer: (D)

Caloric testing and VEMP assess different parts of the vestibular system, so when a disorder affects multiple vestibular pathways, both tests tend to be abnormal. In Menière disease, endolymphatic hydrops disrupts both the horizontal semicircular canal function (shown as abnormal caloric responses) and otolith-nerve function (altered VEMP responses), so abnormalities in both are common. In vestibular schwannoma, a tumor on the vestibular nerve can diminish caloric responses on the affected side and also alter VEMP outcomes if the nerve fibers involved include the pathways tested by VEMP. Because both tests reflect different, but overlapping, vestibular components, those two conditions frequently show abnormalities in both caloric testing and VEMP.