| Background In clinical practice,the postoperative hearing rehabilitation performance of cochlear implantees showed large individual variation even if the equipment-related factors were kept consistent.It was thought to be related to the remodeling of the auditory center caused by auditory deprivation.Cortical auditory evoked potential(CAEP)serves as an electrophysiological method to describe the processing of sound signals at the auditory cortical level,with the advantages of being objective,frequency specific,and reflecting complete auditory pathway.However,there have been few studies based on CAEP in adults with postlingual deafness,and no reports on the effects of different intervention modes on CAEP.This study was designed to determine the development patterns of the CAEP in CI users with postlingual deafness,and to compare its difference under different intervention modes.Methods(1)Fifteen adults with normal hearing were selected as the normal hearing group(NH group),in which CAEP test was performed at the stimulus frequencies of 500 Hz,1 000 Hz and 2000 Hz as well as the intensities of 75,65,55,45 and 35 d B SPL.The effect of the frequency and intensity on the P1-N1-P2 characteristic values was analysed.(2)Ten adults with postlingual deafness who received unilateral cochlear implantation in the Guangdong Provincial People’s Hospital were selected as the cochlear implantation group-1(CI-1 group).CAEP test,speech resolution,CAP and SIR scale were evaluated for the patients in the CI-1 group before surgery,1 month and 6 months after operation.Sixteen adults with postlingual deafness who had used cochlear implant more than six months were assigned to the cochlear implantation group-2(CI-2 group),and CAEP test,speech resolution test,CAP and SIR scale were evaluated.The experimental data were analysed for the following.(1)The difference of P1-N1-P2 characteristic values,SRS,CAP and SIR scores between the two time nodes in the CI-1 group;(2)The difference of P1-N1-P2 characteristic values,SRS,CAP and SIR scores between the CI-1 group and the CI-2 group;(3)The difference of P1-N1-P2 characteristic values between NH group and CI-2 group;(4)The correlation between P1-N1-P2 values and SRS,CAP and SIR scores.(3)Eight adult patients with bilateral cochlear implantation were included into the bilateral cochlear implantation group(BCI group).CAEP tests were performed under the four different testing conditions respectively.The difference of P1-N1-P2 induced rates under different test modes was analysed.Results(1)The latency of P1,N1,P2,the peak-peak amplitudes of N1-P1 and N1-P2,and the P1-P2 amplitude ratio were statistically different among different stimulus intensities and the latency of P1 and N1 were statistically different among different frequencies(p<0.05).(2)One patient in CI-1 group was lost to follow-up.(1)The latency of P1 in CI-1 group at6-month follow-up was significantly shorter than that at 1-month follow-up with statistical significance(P<0.05),while there was no difference between the CI-1 group at 6-month follow-up and the CI-2 group.(2)There was no statistical difference in the latency of P1 between the CI-2 group and the NH group,while the latency of N1 and P2,the peak-peak amplitudes of N1-P1 and N1-P2,and the P1-P1 amplitude ratio were statistically different between two groups(p<0.05).(3)The SRS and CAP scores were significantly higher from1-month to 6-month follow-up(P<0.05),while there was significant difference in the SIR scores between the CI-1 group at 6-month follow-up and the CI-2 group.(4)There was no correlation between the latency of P1 with SRS,CAP and SIR scores.(3)In the BCI group,no P1-N1-P2 wave was induced under the condition of no hearing aids,while the induce rate was 100% under the unilateral cochlear implantation test mode,87.5%under the contralateral cochlear implantation test mode,and 37.5% under the bilateral cochlear implantation test mode.Conclusions Typical P1-N1-P2 waves could be induced in adult CI users with postlingual deafness.The latency of P1 in adult CI users with postlingual deafness was shortened within 6-month follow-up and reached a plateau stage at the level of the normal hearing adults.Compared with unilateral cochlear implantation mode,bilateral cochlear implantation mode had greater interference to CAEP test,reducing the induce rate of P1-N1-P2 waves significantly. |
PDF Full Text Request