The Value of Subjective Visual Vertical in Diagnosis of Vestibular Migraine

Objective To study the value of the subjective visual vertical(SVV)in the diagnosis of vestibular migraine(VM).Methods This study recruited 128 VM patients and 64 age-matched normal subjects.We detected the SVV during the interval between attacks in both groups,in sitting upright,and the head tilted at 45°to the left or right.We then examined the correlation between the SVV results with the vestibular evoked myogenic potential(VEMP)and canal paresis(CP).Results It was found there was a significant difference in SVV at the upright position between VM patients and normal controls(P=0.006)and no significant difference was found at the tilts of 45°to the left or right between the two groups.The SVV results at the upright position were significantly correlated with cervical VEMP(P=0.042)whereas not significantly correlated with CP and VEMP.There existed no significant difference in the conformity to the Müller effect(M effect)between the two groups.ROC analysis exhibited that the sensitivity,specificity of SVVs at the upright were 67.200%and 62.500%respectively.The diagnostic value of SVV at the upright position was significantly higher than that at tilts of 45°to the left and right(P=0.006).Nonetheless the diagnostic accuracy was relatively low.Conclusion Abnormality in SVV possibly stems from the lasting functional disorder of cerebellar or high-level cortical centers in VM patients or is linked to the vestibular compensation.The SVV is of low diagnostic value for VM and the value of SVV in VM warrants further study.