The Role of Vestibular Evoked Myogenic Potential and the Video Head Impulse Test in Patients with Multiple Sclerosis without Radiologic Findings

Abstract

Objective: The aim is to evaluate the vestibular system using the video head impulse test (vHIT) and vestibular evoked myogenic potentials (VEMP) in patients with multiple sclerosis (MS) without central vestibular involvement in magnetic resonance imaging (MRI), and to determine whether there was subclinical vestibular system impairment. Materials and Methods: The study comprised 27 patients with MS and 26 healthy participants. The participants had no lesions in the central vestibular system in an MRI taken in the past 3 months. Detailed neuro-otologic and neuro-ophthalmologic examinations were performed on all participants. Then, the Dizziness Handicap Inventory (DHI) was completed for subjective vestibular system evaluation. In addition, vHIT and cervical VEMP (cVEMP) were performed for objective vestibular system evaluation. The results were analyzed statistically. Results: The mean age of the patients in the MS group was 39.3 ± 11.4 years and 42.7 ± 9.7 years in the control group. The median DHI score was 4 (range, 0–8) in the MS group and 2 (range, 0–6) in the control group. There were no statistically significant differences between the DHI score averages of the groups. The mean vestibulo ocular reflex (VOR) gain in vHIT was 0.76 ± 0.21 in the MS group and 0.99 ± 0.13 in the control group. VOR gain was statistically significantly lower in patients with MS. The VOR gain cut-off level was considered as 0.8. Gain level was below the cut-off level in 53.7% of patients with MS. There was no cVEMP response in 31.5% of patients with MS. In addition, patients with MS had prolonged P1 and N1 latencies and decreased P1-N1 peak-to-peak amplitudes. Conclusion: We found subclinical involvement in electrophysiologic tests (vHIT and cVEMP) in patients with MS without MRI lesions and without subjective vestibular system symptoms. We believe that vHIT and cVEMP can be used for subclinical evaluation in patients with MS without central vestibular system involvement in MRI.