Concurrent VVOR and VORS profiling reveals a threshold-dependent VOR suppression deficit in vestibular migraine

To define the dual profile of visual-vestibular integration in vestibular migraine (VM) by concurrently evaluating visually enhanced vestibulo-ocular reflex (VVOR) and vestibulo-ocular reflex suppression (VORS), and to determine which metric more closely reflects disease-related central vestibular dysfunction.

In this retrospective case-control study, 57 patients with VM diagnosed according to the 2022 Bárány Society/ICHD-3 criteria and 30 healthy controls underwent VVOR and VORS testing using video-oculography during passive horizontal head rotation (0.5 Hz, ±15°). Clinical data were collected from medical records. Group differences in VVOR and VORS gains were analyzed, restricted cubic spline (RCS) regression combined with binary logistic regression was used to analyze the dose-response relationship between these indices and VM risk after adjusting for potential confounders.

Compared with controls, patients with VM showed significantly higher VVOR gains (mean: 1.4 ± 0.2 vs. 1.2 ± 0.2, p = 0.003) and markedly elevated VORS gains (0.5 ± 0.2 vs. 0.2 ± 0.1, p < 0.001). VVOR demonstrated a linear relationship with VM risk (nonlinearity p = 0.5629), with risk increasing gradually above 1.32 but high VVOR (≥1.32) was not independently associated with VM (OR = 0.44, 95% CI: 0.13-1.45, p = 0.2). In contrast, VORS showed a significant nonlinear S-shaped association with VM risk (nonlinearity p = 0.0001), showing the steepest rise in risk between 0.39 to 0.60 and a plateau thereafter. A high VORS gain (≥0.39) was strongly associated with VM (OR = 0.01, 95% CI: 0.001-0.08, p < 0.001), identifying VORS impairment as the more clinically relevant abnormality.

This study provides the first simultaneous characterization of the enhancement and suppression arms of visual-vestibular integration in VM. The key contribution is the identification of a threshold-dependent VORS suppression deficit as a more specific indicator of VM-related central dysfunction, consistent with impaired cerebellar inhibitory control, whereas elevated VVOR appears to reflect a less specific adaptive response. These findings refine the physiological understanding of VM and support VORS-based stratification as a potential framework for mechanistic subtyping and targeted vestibular rehabilitation.