Masseter Vestibular Evoked Myogenic Potentials (VEMP) as a Novel Diagnostic Tool in Multiple Sclerosis: A Comparative Study with Cervical VEMP

Abstract

Background: Multiple sclerosis (MS) frequently involves subclinical brainstem lesions that may not be detected by conventional magnetic resonance imaging (MRI). Vestibular evoked myogenic potentials (VEMPs) provide a sensitive electrophysiological tool for assessing functional integrity of the brainstem. This study compared cervical VEMP (cVEMP) and masseter VEMP (mVEMP) in detecting brainstem dysfunction in patients with MS.
Methods: A cross-sectional comparative study was conducted on 30 female patients aged 18-60 years with relapsing–remitting MS (RRMS), diagnosed according to the 2017 McDonald criteria, and 30 healthy female controls aged 18–60 years. All participants underwent detailed audiological assessment, tympanometry, acoustic reflex testing, and both cVEMP and mVEMP recording using air-conducted stimuli. Latencies (P13, N23) and amplitudes were analyzed. Data were statistically evaluated using t-tests and receiver operating characteristic (ROC) analysis.
Results: No significant differences were found in pure-tone thresholds, speech reception thresholds, or tympanometry between groups (p > 0.05). MS patients showed significantly prolonged cVEMP P13 and N23 latencies (p < 0.001) and reduced amplitudes, indicating vestibulo-collic pathway dysfunction. mVEMP responses revealed more pronounced latency prolongation and amplitude reduction (p < 0.001), suggesting a slightly higher sensitivity for detecting trigemino-vestibular pathway involvement. ROC analysis showed AUC values of 0.78–0.88 for cVEMP and 0.81–0.89 for mVEMP, with mVEMP demonstrating higher sensitivity (up to 95%) and greater accuracy (73%). Abnormal VEMP findings significantly correlated with MRI-confirmed brainstem lesions (p < 0.05) as the distribution pattern particularly the periventricular and subcortical white matter involvement is classically characteristic of demyelinating disease.
Conclusion: Both cVEMP and mVEMP are sensitive measures of subclinical brainstem dysfunction in MS, with mVEMP offering slightly higher sensitivity and diagnostic accuracy. VEMP testing, particularly mVEMP, may serve as a valuable adjunct to MRI in early detection and monitoring of brainstem involvement in MS.