The Vertebral Basilar Artery Morphology And Cerebral Perfusion In Patients With Undetermined Isolated Vertigo

BackgroundVertigo is a common symptom in neurology,and it is also a common complaint for patients in otorhinolaryngology and emergency department.It can result from various causes involving multiple disciplines,and clinical diagnosis often brings clinicians confused and has a high misdiagnosis rate.The classification of the cause of vertigo is mainly divided into vestibular peripheral and central vertigo.The prognosis of the two is different.If the central vertigo is not diagnosed and targeted timely,it will bring disastrous consequences.Therefore,it is crucial to accurately distinguish the peripheral and central vertigo.Isolated vertigo(IV)refers to the clinical onset of only typical vertigo without accompanying other inner ear and neurological symptoms and signs.Through electrophysiology and imaging examinations for the otology and nervous system,only some causes of IV can be found out while the others fail at the time of the onset.We call it the latter Undetermined Isolated Vertigo(UIV),which can be either peripheral vestibular vertigo or central vestibular vertigo.In recent years,many studies have found that in UIV patient,the more vascular risk factors,the greater the risk of stroke,and that for the UIV patients should be considered due to vascular mechanisms.With the development of magnetic resonance technology,some researchers have suggested that the occurrence of vertigo may be related to the morphological change of the basilar artery(BA)and vertebral artery(VA)and the disequilibrium of cerebral perfusion.The risk of long-term stroke is significantly higher than that of the general population.Therefore,it is necessary to conduct an in-depth study on the morphology of BA and VA and the status of cerebral blood perfusion in UIV patients,so as to provide a scientific basis for the prevention of stroke.purposesThis study was designed to analyze and explore vascular risk factors of UIV patients,and evaluate the morphology of BA and VA and the status of cerebral blood perfusion,further discuss the risk and possible mechanism of stroke in UIV patients associated with them,so as to provide a scientific basis for the prevention of stroke.MethodsThis was a prospective and observational study.A total of 36 patients with recurrent vertigo from June 2018 to December 2019 were selected,including UIV group(20 individuals)and BPPV group(16 individuals).All patients underwent MR examination within 48 hours of the onset of symptoms.At the same time,14 healthy individuals who are undergoing MR scan without vertigo and intracranial disease were collected as the control.The vascular risk factors including gender,age,family history,past history,and body mass index(BMI)were analyzed;The morphological changes of the vertebrobasilar artery(VBA)including basilar artery curvature and vertebral artery dominance were also analyzed by MRA.Evaluating cerebral perfusion by measuring the region of interest(ROI)parameters,including the relative cerebral blood volume(rCBV),relative cerebral blood flow(rCBF),time to peak(TTP)and mean transit time(MTT).To facilitate comparison between the three groups,we further calculated the absolute difference of relative parameter values between two mirrored ROIs.Then rrCBV,rrCBF,rTTP and rMTT were obtained respectively.The relationship among the risk factors,morphological changes of VBA and cerebral perfusion in UIV was analyzed discussed.Results1.The incidences of hypertension,and more than 3 vascular risk factors in UIV group were significantly higher than the other two groups(P<0.0166);other risk factors were not found to be significantly different from the other two groups(p>0.0166).2.Neuroimaging evaluation(1)In UIV patients,16 patients(80.00%)were combined with VAD,and 14 patients(70.00%)were combined with BAC.The incidence of VAD and BAC was higher than the other two groups.Compared with the othertwo groups,the incidence of VAD was statistically significant(p<0.05),but No significant differences were found in the the incidence of BAC(p>0.05).There was no statistical difference in the basilar artery length(BAL)between the three groups(p>0.05),but compared with the bending length(BL)of the BA,the average length of the UIV group was 5.64 ± 2.00 mm,statistical differences between the other two groups(p<0.05).(2)In UIV patients,the significant differences were found in the rMTT and rTTP(the absolute difference of MTT,TTP values of mirrored ROIs)in cerebellar and rTTP(the absolute difference of TTP values in mirrored ROIs)in brainstem was larger than the other two groups(p<0.0166).(3)Based on whether or not BAC was combined,comparing UIV patients with PWI in the group found that rMTT in the brainstem on Plane of vestibular nucleus of BAC patients was differ from of non-BAC patients(p <0.05).ConclusionUIV patients are associated with 3 or more vascular risk factors;The incidence of VAD was high.At the same time,we found that disequilibrium in the MTT,TTP of the bilateral cerebellum and the TTP of left and right parts of brainstem in UIV patients.This cerebral perfusion disorder may be the possible mechanism for the occurrence of vertigo in UIV and the development of a recurrent transient ischemic attack or infarction.