Evaluation of vertigo by auditory brain stem response.

The authors examined the hypothesis that abnormal patterns of the auditory brain stem response (ABR) could supplement the neuro-otological evaluation and assist in localizing the site of vestibulocerebellar dysfunction. This project is based upon the fact that the sources of waves I through V have been regionally identified. Absent or delayed patterns can be referenced to the normal data, and the site of a lesion generating vertigo can be established. We found absence of waves or prolonged interpeak latencies in 25% of the vertiginous subjects with normal hearing and magnetic resonance images of the brain. We conclude that in selected cases, lesions affecting the vestibular system can influence the ABR, and the electrophysiological tests of audition may suggest regionalization of the dysfunction in the hindbrain and midbrain.