Objectives: To assess whether patient age or sex was predictive of a bilaterally absent cervical or ocular vestibular evoked myogenic potential (cVEMP or oVEMP).
Study design: Retrospective case review.
Setting: Tertiary center.
Patients: Patients presenting with normal vestibular tests (i.e. normal caloric and rotational chair) who underwent cVEMP and/or oVEMP testing. Patients with conductive hearing loss were excluded as were those with unilaterally abnormal VEMP results because they presented with evidence of a possible unilateral vestibular impairment. A total of 895 patients met criteria for cVEMPs and 297 for oVEMPs.
Main outcome measures: The presence or absence of cVEMP and oVEMP responses elicited with a 500-Hz 125-dB pSPL air conduction stimulus.
Results: A logistic regression was performed including odd ratios and confidence intervals. Compared with adults in their 20s, the odds of bilaterally absent cVEMP responses are 6 times greater for patients in their 50s and 60s and over 22 times greater for patients in their 70s and 80s. A bilaterally absent oVEMP response is 6 times more likely for patients in their 40s, 50s, and 60 and 13 times greater for patients in their 70s.
Conclusions: VEMPs in response to air conduction stimuli are bilaterally absent in a large percentage of older patients complaining of dizziness who otherwise have normal vestibular and auditory testing for their age. In combination with other abnormal vestibular findings, an absence of VEMP responses may be of value. However, the functional consequence of an isolated bilaterally absent VEMP is not known and may provide minimal information to an older patient's diagnostic picture. In cases where the response is bilaterally absent, a more intense AC stimulus should be used or bone conducted vibration should be considered.