Vestibular-evoked myogenic potential: an easy neurophysiological tool for evaluating brain stem involvement in multiple sclerosis

Abstract

Background: Vestibular-evoked myogenic potentials (VEMPs) are an applicable neurophysiological technique that can be used for diagnosis of brain stem involvement in patients with multiple sclerosis (MS). Aim: The aim was to evaluate the relationship between VEMP parameters, clinical characteristics, and brain stem lesions in patients with MS. Patients and Methods: The study was a case–control study done on 20 patients with MS and 10 normal controls. The disability level of the patients was assessed by the expanded disability status scale and brain stem functional system score (FSS). Location of demyelinating lesions was determined from brain and spinal cord MRI scans. VEMP was done for all patients and controls. Results: Overall, 60% (n=12) of patients with MS were found to have absent VEMP latency (P13–N23) in both right and left side. Patients with preserved VEMP latency were found to have significantly delayed latency (P13–N23) in both right and left sides than controls. Comparison between patients with delayed VEMP latency and those with absent VEMP latency in disease characteristics revealed that there was a statistically significant difference between them in disease duration (P=0.001), expanded disability status scale score (P=0.01), and functional system score (P=0.04). The group of patients with vestibular symptoms or brain stem lesions was found to have significantly more absent VEMP latency than those without. Conclusion: Patients with MS may have abnormal VEMP, especially those with long disease duration, vestibular symptoms, greater disability, and brain stem lesions.