Study Of ECAP Measures In Cochlear Implant Users With DPOAE Result Partly Abnormal

Objective:The purpose of this study was to explore the clinical diagnosis of the cochlear and retrocochlear damages through investigating the ECAP recorded in the NRT after implanting cochlear of the patients ,and evaluate the effect of cochlear implantation with MAIS ,whose major clinical manifestations of the hearing loss are severely abnormal ABR findings accompanied with partly abnormal DPOAE result.Method:This is a retrospective case control study. In 226 unilateral cochlear implantation patients between 2002 and 2010,18 cases with partly abnormal DPOAE result were enrolled in group A and 18 cases with completely abnormal DPOAE result were enrolled in group B. The responses of DPOAE were analyzed and the thresholds of DPOAE were compared among the group A and B. The responses of ECAP were analyzed and the thresholds of ECAP were compared among the group A and B. The score was compared among the group A and B.Result:1,The DPOAE results showed that intermediate frequency and high frequency were elicited in group A.2,The non-eliciting rates in group A in intraoperative,initial stimulation,3 months after initial stimulation and 3 times were higher than in group B, and there were statistical significance between the two groups. In group A and B, the non-eliciting rates were different between surgery and initial stimulation,surgery and3 months after initial stimulation, and there were statistical significance. But no significant differences of the non-eliciting rates were found between initial stimulation and 3 months after initial stimulation. There were not statistical significance in the difference of the non-eliciting rates of each electrode except the number 2 electrode intraoperative between the two groups. Except that the threshold means of electrode 10 in initial stimulation were similar, ECAP thresholds in group A were higher than in group B at each time point, and significant differences were found in electrode 22 intraoperative and electrodes 2,6,18,22 between the two groups.3,The scores of questions 3-10 in group A and B at postoperation were higher than at preoperation, and there were statistical significance between the two times. At postoperation,the scores of questions 1-10 in group A were higher than in group B, and there were not statistical significance between the two times.4,There were not statistical significance in the difference of the age between the two groups.Conclusion:There were damage in the cochlears of the patients whose DPOAE results show partly abnormal, but some out hear cells remained normal function. The cells were located in intermediate and high frequency corresponding cochlear area.The sensorineural deafness patients with cochlear impairment, some of which have retrocochlear auditory nerve impairment at the same time. The clinical features that DPOAE result shows partly abnormal and ABR result is severe abnormal provide an important proof for diagnosis of cochlear and retrocochlear damages. In this study, the main site of lesion of the patients with these features is in spiral ganglion or auditory nerve , or both of them.In this study, the effect of implanting cochlear to the patients with these features have no significant difference compared with cochlear damaged patients. These features are not the contraindication for implanting cochlear, and are the indication for it.