Elevated ocular VEMP responses in the absence of a superior semicircular canal dehiscence.

BACKGROUND

Vestibular evoked myogenic potentials (VEMPs) have an accepted role in the diagnosis of the superior semicircular canal dehiscence (SSCD) syndrome. The current impression is that ocular VEMPs (oVEMPs) are more sensitive than cervical VEMPs (cVEMPs) for detecting a SSCD and that oVEMP testing in response to air conducted sound provides an excellent screening test without risk of radiation exposure from computerized tomography (CT).

AIMS/

OBJECTIVES

To report on patients with elevated oVEMP amplitudes but without evidence for a SSCD on multiplanar CT imaging.

MATERIAL AND

METHODS

Retrospective chart review of all patients referred for vestibular function testing to our department. Patients with oVEMP peak-to-peak amplitudes ≥17 μν without evidence for a SSCD on imaging were evaluated.

RESULTS

26 patients had oVEMP peak-to-peak amplitudes ≥17 μν with no evidence of a SSCD on imaging. The most common diagnosis was Meniere's disease in those identified.

CONCLUSION AND SIGNIFICANCE: oVEMPs can provide false positive results for diagnosis of a SSCD and an elevated oVEMP amplitude in itself is insufficient for diagnosis of a SSCD.