Changes of brainstem auditory evoked potential in patients with vertebral artery dominant vertigo and its clinical significance

Objectives To investigate the changes of brainstem auditory evoked potential (BAEP) in patients with vertebral artery dominant vertigo and to explore the possible mechanism of vertigo. Methods Thirty-five patients with consecutive vertebral artery dominant vertigo detected by head magnetic resonance angiography (MRA) were included prospectively as the study group, and 29 patients without vertebral artery dominant vertigo as the control group.The age, sex, and other clinical histories were comparable in both groups.The degree of vertigo of the patients was graded and the BAEP examination was performed. The basilar artery and the changes of BAEP and its relationship with the dominant vertebral artery in patients of the two groups were analyzed.Results Thirty-five patients with vertebral artery dominant vertigo and 29 patients without vertebral artery dominant vertigo were selected.①The abnormal rate of basilar artery was 60% in the vertebral artery dominant group, and it was higher than 34.5% in the vertebral artery non-dominant group.There was statistically significant difference (x~2=4.135 , P 0.05).The median value of basilar artery curvature was 3.67 mm in the dominant group, and it was larger than 1.73 mm in the non-dominant group.There was statistically significant difference (P 0.01) .②The peak latencies of Ⅰ, Ⅲ and Ⅳ wave in the dominant group were longer than those in the non-vertebral artery non-dominant group (P 0.01).However, the difference of the peak latency of HI wave did not reach statistical significance.Both the interpeak latencies of Ⅲ-Ⅴ and Ⅰ-Ⅴ in the vertebral artery dominant group were longer than those in the non-vertebral artery non-dominant group (P 0.05) , and there was no statis- tical significance in the interpeak latencies of Ⅰ-Ⅲ (P 0.05).The ratios of Ⅲ-Ⅴ/Ⅰ-Ⅲ in the vertebral artery dominant group was larger than those in the non-dominant group (P 0.05).③There was significant difference in the vertigo severity scale between the patients of vertebral artery dominant group (3.2±1.0) and those of vertebral artery non-dominant group (2.2 ±0.7) (P0.01).There were correlations between the vertigo severity scale of the vertebral artery dominance and each major abnormal item of BAEP.Of those, the correlations of Ⅲ-Ⅴ/Ⅰ-Ⅲ were the most significant (r=0.617, P=0.013). Conclusions The abnormal rate of basilar artery, the abnormal rate of BAEP and the vertigo severity scales are higher in patients with vertebral artery dominance.There is correlation between the vertebral artery dominance and the abnormal BAEP.