Vestibular evoked myogenic potentials in idiopathic posterior canal benign paroxysmal positional vertigo

Abstract

Objective: The involvement of the utricle and possibly the saccule in the pathogenesis of BPPV encouraged many investigators to study VEMP in patients with BPPV. The current study investigated VEMP results in patients with BPPV to determine different forms of VEMP abnormalities (if any) in patients with BPPV. Study design: The study group comprised 112 patients (52 males, 60 females; age range 26−60 years (46.2 ± 10.2)). The group was subdivided into a recurrent BPPV subgroup (32 patients) and a non-recurrent BPPV subgroup (80 patients). The control group included 100 healthy volunteers with matched age and gender distribution. Both ocular vestibular evoked myogenic potentials (oVEMP) and cervical vestibular evoked myogenic potentials (cVEMP) were registered in the different study subgroups. Abnormal VEMP was defined as: 1) VEMP pattern of ‘no response’; 2) VEMP asymmetry exceeding the mean + 2 SD of the control group; 3) delayed peak latency (P13 or N1) exceeding the mean + 2 SD of the control group. Results: The prevalence of VEMP abnormalities in patients with BPPV was 9.8% for oVEMP, 13.4% for cVEMP and 20.5% when VEMP abnormality was defined as an abnormal oVEMP and/or abnormal cVEMP. VEMP abnormalities in the recurrent BPPV patients were 40.3%, and 12.5% in the non-recurrent BPPV group. All forms of VEMP abnormalities were detected in the study group (i.e. absent, asymmetrical or delayed VEMP peaks); the absent VEMP was the most prevalent form of abnormality. The recurrent BPPV group had significantly higher oVEMP and cVEMP compared to either control or non-recurrent groups. cVEMP was significantly higher in the non-recurrent BPPV than controls, but oVEMP was not. Conclusions: VEMP abnormalities were detected more in patients with recurrent attacks of BPPV suggesting that VEMP abnormality may be indicative of the risk of BPPV recurrence. cVEMP may be a more sensitive tool for detection of early mild effects of pathological disorders causing dual affection of the utricle and saccule.

Key words::

• cervical VEMP
• ocular VEMP
• recurrent BPPV

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.