Analysis Of The EABR Characteristics Of Patients After Cochlear Implantation

Objective: To analyze the difference of electrically evoked auditory brainstem response in low,middle and high frequency electrodes of cochlear implantation in deaf patients,to study the influence of gender,CI implantation time,implantation age,residual hearing,inner ear morphology and unilateral or bilateral implantation on the characteristics of postoperative EABR.To explore the feasibility of using EABR to evaluate the effect of hearing and speech rehabilitation after CI operation.Methods: 92 patients who were diagnosed with severe and extremely severe sensorineural deafness and treated with CI operation in the Department of Otolaryngology,Second Hospital of Lanzhou University from 2012 to 2021 were selected as study subjects,and the time of implantation was more than half a year.All subjects were tested by EABR after operation.Mark the latency of III wave,III-V wave interval and V wave in EABR and the threshold of EABR,and compare the differences of each index of EABR according to different genders,CI implantation time,implantation age,residual hearing,inner ear morphology and unilateral and binaural grouping.Results:1.The EABR V wave extraction rate of 152 ears was 98.03%,100% and 87.5%in low frequency,middle frequency and high frequency regions.the III wave latency,V wave latency,III-V wave interval and EABR threshold showed statistical differences among the three groups in low,middle and high frequency region（P<0.05）,The latency,wave interval and EABR threshold of the test ears all follow the law of minimum low frequency and maximum high frequency.There is no statistical difference between the latency and wave interval in low frequency area group and middle frequency area group（P>0.05）.and there were differences in EABR threshold between low,middle and high frequency group in pairwise comparison（P<0.05）.2.There were statistically significant differences between male and female in the latency of V wave in the middle frequency region and the threshold of EABR in the high frequency region of cochlea（P<0.05）,and the latency and threshold of EABR in female patients were significantly lower than those in male patients,female patients were more sensitive to the high frequency region.The characteristics of EABR were compared among four groups according to CI implantation time,indicating that the latency,wave interval and EABR threshold have statistical significance among the four groups（P<0.05）.3.The effect of age of implantation on EABR was compared in groups,and there was no statistical difference in EABR indicators in different age groups（P>0.05）.4.Group comparison of the effects of residual hearing on EABR showed that there was no statistical difference in the latency of III wave between the two groups（P>0.05）,and there was statistical difference in the latency of V wave between the two groups in the low and middle frequency region（P<0.05）.The latency of the group with residual hearing was always shorter than that of the group without residual hearing at all frequencies.The EABR threshold of the group with residual hearing was lower than that of the group without residual hearing,and there was statistical difference between the two groups in the low frequency region,while there was no statistical difference between the middle frequency region and the high frequency region.5.Group comparison of the influence of inner ear morphology on EABR,there was no statistical difference in EABR index between the EVA malformation group and the non-malformation group,EVA malformation group and EVA+IP-II malformation group,non-malformation group and EVA+IP-II malformation group were statistically different in low threshold and middle frequency threshold（P<0.05）.There were statistical differences in low and middle frequency threshold and middle and high frequency V wave latency between the malformation group and other malformation group,EVA malformation group and other malformation group.（P<0.05）.There were significant differences in low frequency threshold and middle and high frequency V wave latency between EVA+IP-II malformations and other malformations（P<0.05）.EVA+IP-II malformation and other malformation groups have statistical differences in low frequency threshold and middle and high frequency V wave latency（P<0.05）.6.A grouping comparison of the effects of unilateral and bilateral CI on EABR showed that the low frequency region EABR threshold and the middle frequency region threshold had statistical differences between the two groups（P=0.018,P=0.021）,and other indicators of EABR had no statistical differences between the two groups with bilateral CI and unilateral CI implantation（P>0.05）.Conclusion:1.After cochlear implantation,EABR had higher extraction rate in low and middle frequency regions,and lowest extraction rate in high frequency region.The latency,wave interval and threshold characteristics of EABR are different in low frequency,middle frequency and high frequency regions.2.The duration after cochlear implantation affected the performance of EABR.The wave interval and threshold of EABR were higher one year after implantation,and the latency and threshold of EABR were significantly better three years after implantation.3.Gender,preoperative residual hearing and inner ear morphology had significant influence on the characteristics of EABR after CI,and there were no significant differences in latency,wave interval and threshold of EABR after CI among patients of different age.4.Compared with unilateral implantation,bilateral implantation especially simultaneous bilateral CI,had better EABR performance.