The role of vestibular evoked myogenic potentials in multiple sclerosis-related vertigo. A systematic review of the literature

Background: Vertigo is a common symptom of multiple sclerosis (MS) that can be caused by a central or peripheral involvement of the vestibular pathways. Magnetic Resonance Imaging (MRI) is commonly used to evaluate progression of MS but is not sensitive enough to detect small lesions. Vestibular evoked myogenic potentials (VEMPs) are commonly used to evaluate function of vestibular-cochlear pathways. The aim of this literature review is to evaluate the role of VEMPs in patients with MS-related vertigo as a tool to detect demyelinating lesions in the vestibular pathways of MS patients and to monitor MS progression. Methods: Following the PRISMA guidelines, we performed a literature search with the following keywords: multiple sclerosis, vertigo, dizziness, equilibrium disorders, vestibular disorders, and VEMPs. Three different databases (PubMed, Scopus, and Google Scholar) were independently screened by two researchers. Publications in English, Italian, French, and Spanish were considered and reviewed by a native speaker. Details on patients' gender, age, and stage of MS, as well as VEMPs, MRI, and vertigo features (including their onset as a function of MS stage) were collected. Percentage and odds ratio were calculated. Spearman test was used to correlate vertigo, VEMPs, and MRI features. Results: Thirty-five articles and 819 patients were included in the study. Nearly 37% of MS patients suffered from vertigo and 71% showed altered VEMPs. Central vestibular pathways were involved in the MS demyelination mostly in the early stage of the disease, while the peripheral vestibular system was mainly affected in late stage MS. A significant percentage (35.4%) of the patients with altered VEMPs showed normal MRI. Conclusions: Our results suggest that VEMPs may detect very small lesions in the vestibular pathways of MS patients; thus, they could have a role in the diagnosis of MS-related vertigo and in the monitoring of vertigo in MS patients as a tool additional to traditional MRI.