Retinal nerve fiber layer thickness and visual aura mechanism in patients with vestibular migraine with or without white matter lesions

Background & Objective: The pathogenesis of vestibular migraine (VM) is still unclear. A considerable proportion of patients with VM have white matter lesions (WMLs). We sought to determine whether the presence of WMLs was related to the thickness of the retinal nerve fiber layer (RNFL) in VM patients. We also investigated the relationship of visual aura to the thickness of the RNFL and explored the possible mechanisms of visual aura. Methods: This study was a large single-center, prospective, controlled study. A total of 50 patients with VM with or without visual aura and 50 healthy controls were recruited. We assessed WMLs using cranial magnetic resonance imaging (MRI) and measured RNFL thickness using optical coherence tomography (OCT). The relationship between RNFL thickness and WMLs was analyzed. RNFL thicknesses for the aura group, non-aura group and control group were compared. Results: (1) The RNFL of the VM group was significantly thinner than that of the control group. (2) When VM patients were divided into two groups based on the presence or absence of WMLs, the RNFL of VM patients with WMLs was significantly thinner, while the RNFL of VM patients without WMLs was significantly thicker, than that of the controls. (3) When the VM group with WMLs was subdivided into two groups according to the presence or absence of visual aura, we found no significant difference in the RNFL thickness of the subgroups with and without visual aura. However, the RNFL thickness of the control group was significantly greater than that of the VM with WML groups with or without visual aura. (4) Finally, when the VM group without WMLs was subdivided into two groups according to the presence or absence of visual aura, there was no significant difference between the RNFL thicknesses of the 2 subgroups. The RNFL thickness of VM patients without WMLs with and without visual aura was greater than that of the control group. Conclusion: Among VM patients, RNFL thinning is positively correlated with the presence of WMLs, while visual aura symptoms are not significantly related to RNFL thickness, indicating that the mechanism of visual aura may not be a disorder of the vascular system. If WMLs develop in VM patients in the future, repeated assessment to look for an associated decrease in RNFL thickness may be helpful.