Features of vestibular evoked myogenic potential in patients with residual dizziness after canalith repositioning procedures for benign paroxysmal positional vertigo

Abstract

Objective: To ananlyze the characteristics of the vestibular evoked myogenic action potential of patients with residual dizziness after successful canalith repositioning procedures(CRP)for idiopathic benign paroxysmal positional vertigo(IBPPV).Method: Ninety-seven consecutive patients with IBPPV of the unilateral posterior semicircular canal and health controls were initially enrolled. The patients received 500 Hz tone burst evoked ocular vestibular evoked myogenic potentials(oVEMP) and cervical vestibular evoked myogenic potentials (cVEMP). After successfully CRP, the patients were divided into two groups: group with residual symptoms and group without residual symptoms. The abnormality of results of both oVEMP and cVEMP were compared between three groups.Result:In the group with residual symptoms, the abnormal rate were 64.5% for oVEMP and 28.1% for cVEMP. In the group without residual symptoms, the abnormal rate were 17.9% for oVEMP and 12.5% for cVEMP. The abnormal rate of oVEMP in the group with residual symptoms was significantly higher than that in the group without residual symptoms(χ²=19.228, P=0.000). However, there was no significant difference in the abnormal rate of cVEMP between these two groups(χ²=3.342, P=0.068).Conclusion: In patients with IBPPV underwent successful CRP,the occurrence of residual symptoms is correlated to the abnormalities of oVEMP. It is indicated that the dysfunction of the utricle is related to the presence of residual symptoms after the CRP for IBPPV.