Study On The Correlation Between Preoperative Residual Hearing And Rehabilitation After Cochlear Implant

Objective: To retrospectively analyze the clinical data of patients underwent unilateral cochlear implantation,analyze the correlation between residual heraring and inner ear morphology,explore the internal relationship between preoperative residual hearing and auditory speech ability after CI,and reveal the value of preoperative residual hearing in evaluating the effect of postoperative hearing and speech rehabilitation in patients with CI.Methods: We selected 383 patients who underwent unilateral cochlear implantation in the Department of Otolaryngology,Head and Neck Surgery,Second Hospital of Lanzhou University from 2012 to 2015.The clinical data of the patients were collected,all patients were divided into 4 groups,included normal structure group,EVA malformation group,EVA+IP-II malformation group,and other inner ear malformations,according to the Sennaroglu inner ear malformation classification standard.The residual hearing distribution of each group was compared,and the correlation between inner ear structure and residual hearing was analyzed.According to the preoperative ASSR test results,patients were divided into residual hearing group and non-residual hearing group.The patients were followed up regularly after the operation and evaluated their hearing and speech rehabilitation.The results were analyzed statistically using SPSS 26.0 software,we studied the differences in the postoperative efficacy of CI in different subgroups,and correlation analysis between residual hearing threshold and curative effect after CI was carried out.Results:1.Imaging diagnosis of the incidence of inner ear malformations in this group of cases was 25.07%.The three most common inner ear malformations were EVA malformations,EVA+IP-II malformations,and IP-II malformations.2.Preoperative audiological assessment and residual hearing: All patients were diagnosed with severe or extremely severe sensorineural hearing loss after clinical examination and audiological examination,the detection rate of ABR for residual hearing was 13.97%,and the detection rate of ASSR for residual hearing was 60.12%.According to the shape of the inner ear,all patients were divided into 4 groups:normal inner ear structure group,EVA malformation group,EVA+IP-II malformation group and other inner ear malformations.The distribution of ABR threshold between each group was significantly different(P<0.001).The comparison between the two groups showed that there was no difference in the ABR threshold distribution between the EVA malformation group and the EVA+IP-II malformation group,which had better residual hearing than the normal inner ear structure group and other inner ear malformation groups,and the difference was statistically significant.The ASSR results are consisten with this.The distribution of residual hearing at each frequency of the 4 groups is significantly different(P < 0.001).Among them,the EVA malformation group and the EVA+IP-II malformation group have higher ASSR thresholds than those of the normal inner ear structure group and others.The inner ear deformity group had better residual hearing,and the difference was statistically significant.3.Correlation between preoperative residual hearing and postoperative hearing and speech rehabilitation in patients with CIThe comparison of the overall sample who accepted ASSR test showed that the recognition rate of tones,Yangyange words,and standard Chinese sentences in a quiet environment of patients with residual hearing group was better than that of the group without residual hearing,and the difference was statistically significant(P<0.05).Among patients with normal inner ear structure,the recognition rate of monosyllable characters,vowels,tones,Yangyange words,and Chinese standard phrases in a quiet environment of patients with residual hearing group was better than that of patients without residual hearing group,and the difference was statistically significant(P<0.05).However,there was no similar correlation between residual hearing in the inner ear deformity group and the postoperative curative effect.There was no statistically significant difference in hearing threshold,questionnaire assessment and open speech recognition rate between the residual hearing group and the non-residual hearing group(P>0.05).4.Correlation between preoperative residual hearing threshold and postoperative hearing and speech rehabilitation in patients with CICAP score and SIR score are negatively correlated with each ASSR frequency thresholds and average hearing threshold.Tones are negatively correlated with1.0kHz residual hearing and recognition.Younger word recognition rate is negative with 1.0 kHz,2.0 kHz,4.0kHz and average hearing threshold.The recognition rate of Chinese standard sentences in a quiet environment is negatively correlated with 0.5kHz,1.0 kHz and the average hearing threshold,and there is no correlation between the other frequencies.0.5kHz residual hearing is negatively correlated with CAP score,SIR score and standard Chinese phrase recognition rate in a quiet environment.1.0kHz residual hearing is negatively correlated with CAP score,SIR score,tone,Yangyange words and standard Chinese phrase recognition in a quiet environment.Both the 2.0kHz and4.0kHz residual hearing are negatively correlated with the CAP score,SIR score and the recognition rate of Yangyange words.The average hearing threshold of ASSR is negatively correlated with the CAP score,SIR score,Yangyange words and the recognition rate of standard Chinese short sentences in a quiet environment.Conclusion:1.The audiological characteristics of patients with EVA malformation and EVA+IP-II malformation are consistent,and the residual hearing is better than those of the normal inner ear structure group and other inner ear structural malformations.2.To a certain extent,residual hearing affects the postoperative hearing and speech rehabilitation effect of CI patients with normal inner ear morphology,but has no obvious effect on the postoperative effect of CI patients with inner ear deformity.3.Low-frequency residual hearing has certain positive benefits for the postoperative rehabilitation of CI patients,especially for the early hearing and speech rehabilitation of patients.Intraoperative preservation of residual hearing is also a practical need for postoperative rehabilitation.4.For most patients with sensorineural hearing loss whose residual hearing is not induced by ABR and ASSR,CI surgery can also obtain a certain degree of curative effect.5.In the non-syndromic sensorineural hearing loss population who underwent CI surgery,the incidence of inner ear malformations was 25.07%.The three most common inner ear malformations in CI patients were EVA malformation,EVA+IP-II malformation and IP-II deformity.