Retinal Nerve Fiber Layer Thickness And Visual Aura Mechanism In Patients With Vestibular Migraine With Or Without White Matter Lesions

Objective:The pathogenesis of vestibular migraine(VM)is still unclear,and the corresponding clinical studies are few.In our clinic,we found that a considerable proportion of VM patients had white matter lesions(WMLs).This study explores whether WMLs in VM patients is related to retinal nerve fiber layer(RNFL)thickness.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 is a single-center,prospective,cross-sectional controlled study.A total of 50 VM patients with or without visual aura were screened and recruited in The Second Affiliated Hospital of Nanchang University from September 2019 to September 2021,and 50 age-sex-matched patients were recruited.We assessed WMLs using cranial magnetic resonance and measured RNFL thickness using optical coherence tomography(OCT).Matched healthy controls were used to analyze the relationship between RNFL and WMLs.Then,based on the presence or absence of WMLs,differences in RNFL between the visual aura group and the non-visual aura group and healthy controls were analyzed to explore the source of the difference.Results:1.Basic information:Among the 50 patients with VM,23(46%)had aura symptoms and 27(54%)had no aura symptoms.WMLs was found in 34(68%)patients and no evidence of WMLs was found in 16(32%).The mean age of VM patients was 46.92 ±14.38 years,including 9 males(18%)and 41 females(82%).The average age of the healthy control group was 49.52 ± 13.39 years,including 13 males(26%)and 37 females(74%).There was no significant difference in gender and age between VM patients and healthy controls.2.Retinal nerve fiber layer thickness analysis:(1)Compared with the healthy control group,the thickness of RNFL in VM patients was smaller and statistically significant(100.48 micron: 105.16 micron,P =0.017).(2)VM patients were divided into two groups according to the presence or absence of WMLs.Compared with the healthy control group,the three groups were analyzed by variance analysis(ANOVA)and Tukey post-test.It was found that there was statistical significance in the three groups(P < 0.001).The RNFL thickness of VM patients without white matter lesions was thicker than that of healthy controls,and the RNFL thickness of VM patients with white matter lesions was the thinnest among the three groups.(3)In 34 patients(68%)with VM with WMLs,18 patients with aura and 16 patients without aura were compared with the healthy control group.The RNFL thickness of the three groups was analyzed by variance.It was concluded that there was no significant difference between the RNFL thickness of patients without aura and those with aura(P = 0.089).The thickness of the group with or without visual aura was significantly higher than that of the control group,and it was statistically significant(P < 0.001).(4)Among the 16 patients(32%)with VM without WMLs,5 patients with aura and 11 patients without aura were compared with the healthy control group.The RNFL thickness of the three groups was analyzed by variance.It was considered that the RNFL thickness of patients with aura was not statistically significant compared with that of the non-Aura group(P = 0.125),and the thickness of the aura group was significantly higher than that of the control group(P = 0.007).Conclusions:1.In VM patients,RNFL thinning is closely related to WMLs.2.There is no significant correlation between visual aura symptoms and retinal nerve fiber layer,indicating that the mechanism of visual aura symptoms may not be the disorder of vascular system,but more support the mechanism of cortical diffusion inhibition theory,which still needs to be verified by other studies in the future.