Significance of Brainstem Auditory Evoked Potentials as an Initial Evaluation for Dizziness

Abstract

The authors performed brainstem auditory evoked potential (BAEP) studies on 207 patients with dizziness symptoms, and evaluated the significance of BAEPs in differentiating among various causes of dizziness. The results showed abnormal BAEPs, which were suggestive of brainstem dysfunction, in 20 of 106 of the probable vertebrobasilar transient ischemic attack (VB TIA) group (18.8%), and in 12 of 101 of the vague dizziness (VD) group (11.8%). Additionally, there were abnormal BAEPs, which were suggestive of the end-organ dysfunction, in 4 of 101 of the VD group (3.9%). When we analysed 32 abnormal BAEPs suggestive of brainstem dysfunction, the most frequent BAEP abnormality was the prolongation of I-III interpeak latency OPt) (53.1%). Prolonged I-V IPL was the second most common abnormality (28.2%), with III-V IPL prolongation occurring less commonly (18.7%). The follow-up studies of abnormal BAEPs showed that the initial abnormal BAEPs reverted to normal in three of six patients, but in the remaining three the abnormality persisted during follow-up period of one to four years. Therefore, it is concluded that BAEP tests would be useful in differentiating the dizziness as one of those symptoms of brainstem dysfunction from non-brainstem syndrome which mimics it.