Estimate On The Function Of Semicircular Canal In Peripheral Vestibular Diseases By Video Head Impulse Test Combined With Caloric Test

The lesion of vestibule system impacts individual daily life and can cause anxiety sometimes.Dizziness,including vertigo,has an effect on 15%-20% adults according to large-sample survey.Vestibular vertigo accounts for a quarter of the total vestibular disease,with a prevalence rate at 5%,which increases with age,and incidence rate at 1.4% per year.The ratio of female patients can be two to three times that of males.20.5%-72.7% of the vertigo outpatients have problems with peripheral vestibular lesions.Several vestibular examinations and detailed history interview are required before giving diagnosis.Caloric test,rotary chair test and head impulsive test are mainly used.Video head impulse test(vHIT)is based on head impulsive test,using camera recording eyeball movement,in order to detect the high frequency function of semicircular canals.vHIT is more objective,simple,comfortable and quantificational than conventional methods,and able to get high disorder rate combined with caloric test.This research is going to estimate the function of semicircular canals with vHIT accompanied with caloric test.Objective: To estimate the function of semicircular canals in peripheral vestibular lesions with vHIT accompanied with caloric test.Methods: Data of patients diagnosed with sudden hearing loss with vertigo,Meniere disease,BPPV,vestibular neuritis,labyrinthine fistula and temporal bone fracture admitted between November 2018 and February 2019 were collected,with a controlled group including 40 healthy adults.All the subjects accepted vHIT and only patients get caloric test.The average value of each semicircular canal and the asymmetry rate of each conjugate plane of the controlled group and disease groups over 10 cases were calculated.The saccades presentation and whether accompanied with lower gain,the disorder rate of vHIT,caloric test and their sum in each disease group were recorded.Statistics process is worked with IBM SPSS Statistics 21 software with p<0.05 marked as significant differentiation.Results: The gain of each semicircular canal of controlled group is close to 1,LARP asymmetry rate is 17.20%±11.53%.61 cases were collected,including 2 sudden hearing loss with vertigo,14 Meniere disease,5 BPPV,3 vestibular neuritis,5 labyrinthine fistula and 2 temporal bone fractures.The lateral canal gain of both injured side and uninjured side,and LARP asymmetry rate of group of sudden hearing loss with vertigo is different with controlled group.Abnormal results of vHIT includes only saccade,only lower gain and both saccade and lower gain.The vHIT disorder rate of each group: sudden hearing loss with vertigo59%(19/32),Meniere disease43%(6/14),BPPV20%(1/5),vestibular neuritis60%(2/3),labyrinthine fistula40%(2/5)and temporal bone fracture100%(2/2).The disorder rate of vHIT combined with caloric test: sudden hearing loss with vertigo 78%,Meniere disease 86%,BPPV 60%,vestibular neuritis 100%,labyrinthine fistula 80% and temporal bone fracture 100%.Conclusions: Video head impulse test has several advantages such as being portable,comfortable,quantificational and able to detect each canal respectively,and is able to diagnose vestibular neuritis accurately,and indicate the severe degree of sudden hearing loss with vertigo and Meniere disease.Saccade should be taken as an manifestation of vHIT disorder.Higher sensibility is available when vHIT is combined with caloric test.