# Cervical vestibular evoked myogenic potential asymmetry, but not amplitude, differentiates vestibular migraine during prolonged unidirectional visual motion

## TL;DR

The study found that asymmetry in cervical vestibular responses, not amplitude, may help identify vestibular migraine after prolonged visual motion.

## Contribution

This study introduces asymmetry in cVEMP responses as a potential diagnostic marker for vestibular migraine.

## Key findings

- cVEMP amplitude was not significantly different between VM patients and controls.
- cVEMP asymmetry significantly differed between VM patients and controls.
- Prolonged visual motion did not affect cVEMP amplitude in VM patients.

## Abstract

Vestibular migraine (VM) is the leading cause of episodic vestibular complaints. It arises from altered brain states that disrupt sensory processing. A reliance on clinical history for diagnosis highlights the need for bedside biomarkers, particularly in emergency settings where misdiagnosis is common.

In this cross-sectional study, 30 VM patients (median-age = 40.5; 27 females) from University College London vestibular clinics and 30 age-gender matched healthy controls (median-age = 32.5; 27 females) were recruited, between May 2024 and October 2025. Cervical Vestibular Evoked Myogenic Potential (cVEMP) responses were measured before and after a Unidirectional Visual Motion Stimuli delivered via virtual reality goggles.

Mixed linear modeling (MLM) showed no significant effects of group, condition or ear on cVEMP amplitude (all p > 0.05). MLM on asymmetry revealed a significant effect of group, F(1, 57.21) = 11.89, p = 0.001 and condition, F(1, 56.53) = 14.47, p = <0.001; but no significant group × condition interaction, F(1, 56.53) = 1.57, p = 0.215. Spearman correlations showed no association between cVEMP delta amplitude and DHI. VM patients scored higher on all symptom’s measures compared with controls (All p < 0.001).

Prolonged unidirectional visual stimulation does not significantly affect cVEMP amplitude responses in VM, limiting its value as a differential diagnostic tool. The need to further explore asymmetry and interaural/interhemispheric sensory integration in VM is underscored.