Impact Of Cochlear Implantation On Vestibular Function

Objective:The objective examination of vestibular function was conducted before and after cochlear implantation.To investigate the influence of cochlear implantation on all five vestibular end-organ functions(saccule,utricule and anterior,lateral,posterior semicircular canal)and accurately understand the damage and prognosis of vestibular organs.In order to provide clinical guidance for ear surgeons to perform more refined operations.Methods:Sixty patients with severe and extremely severe sensorineural deafness who underwent cochlear implantation in Otolaryngology Head and Neck Surgery of Shanxi provincial people’s Hospital form October 2017 to December 2019 were selected,who met the criteria for patient selection in the cochlear implant work guide(ChangSha,2003).Cervical vestibular-evoked myogenic potential(CI-on and CI-off)for saccule function,ocular vestibular-evoked myogenic potentia(CI-on and CI-off)l for utricule function,caloric test for horizontal semicircular canal function of low frequency area and Video head impulse test for semicircular canal functions of high frequency area were performed before,one week,one month and three month after cochlear implant.And the clinical manifestations of patients in different periods were recorded.Data was analyzed using the SPSS software(vision 21.0).Results:The positive rate of cVEMP,oVEMP,caloric test before surgery were 36.67%(22/60),28.33%(17/60),44.44%(12/27)respectively,while the rate one week after implantation were 83.33%(50/60),63.33%(38/60),81.48%(22/27)respecti vely;the rate one month after implantation were 73.33%(44/60),53.33%(32/60),74.07%(20/27)respectively.There were significant differences between pre-opera tion and post-operation(P<0.05).At three month there were 41.67%(25/60),50.00%(30/60),62.96%(17/27),and only oVEMP was significant differences betwee n pre-operation and post-operation(P<0.05).The positive rate of vHIT for anteri or,lateral,posterior semicircular canal before surgery were 22.22%(6/27),18.52%(5/27),25.93%(7/27),and the rate one week after implantation were 25.93%(7/27),37.04%(10/27),44.44%(12/27);the rate one month after implantation were22.22%(6/27),29.63%(8/27),40.74%(11/27)and the rate three month after im plantation were 18.52%(5/27),25.93%(7/27),37.04%(10/27).There were no sig nificant difference in the vHIT results between pre-and post-operation.At one m onth after implantation,the positive rate of cVEMP,oVEMP on CI-OFF were 73.33%,53.33%,while the rate on CI-ON were 66.66%,63.33%.At three month after im plantation,the positive rate of cVEMP,oVEMP on CI-OFF were 41.67%,50%,while the rate on CI-ON were 38.33%,40%.There were significant differences between CI-OFF and CI-ON at three month after implantation.Nineteen patients(31.97%)h ad the symptoms of vertigo,while the symptoms had no correlate with the results of vestibular test.Conclusion:1.CI has different degrees of damage to vestibular end-organ.It has the most significant effect on saccule,followed by the utricule and the low frequency area of lateral semicircular canal,and has the little effect on the high frequency area of semicicular canal.2.Vestibular function can improve over time.3.Vestibular function can improve by electrical stimulation at a certain comfort threshold level.