Cervical vestibular evoked myogenic potentials (cVEMPs) in patients with superior canal dehiscence syndrome (SCDS)

OBJECTIVE: To determine the usefulness of both amplitude and threshold data from tone-burst cervical vestibular evoked myogenic potential (cVEMP) testing for the evaluation of superior canal dehiscence syndrome (SCDS). STUDY DESIGN: Case series with chart review. SUBJECTS AND METHODS: Sixty-seven patients underwent cVEMP testing. We correlated mean tone burst cVEMP amplitude and threshold data with temporal bone CT findings. Patients were excluded for Meniere's disease, middle ear disease. or otologic surgery. RESULTS: Superior canal dehiscence patients had higher mean cVEMP amplitudes (SCDS 173.8 mu V vs non-SCDS 69.7 mu V, P = 0.031) and lower mean thresholds (SCDS 72.8 dB nHL vs non-SCDS 80.9 dB nHL) at 500 Hz. CONCLUSION: Patients with SCDS have larger amplitudes and lower thresholds on cVEMP testing at 500 Hz. This study supports the utility of tone burst cVEMPs for the evaluation of SCDS and is one of few large single-center studies to establish normative data. (C) 2009 American Academy of Otolaryngology-Head and Neck Surgery Foundation. All rights reserved.