皮层听觉诱发电位评估人工耳蜗植入语前聋儿童的中枢听觉系统发育

目的研究人工耳蜗植入语前聋儿童的皮层听觉诱发电位(cortical auditory evoked potential,CAEP)P1波潜伏期的发展规律,评估不同年龄段植入人工耳蜗语前聋儿童的中枢听觉系统的发育。方法以人工耳蜗植入语前聋儿童50例(植入年龄15~66月,平均38.7±15.2月,其中小于42月龄者27例,大于42月龄者23例)和年龄相匹配的正常听力儿童50例为研究对象,采用500、1000、2000、4000 Hz四种频率的短纯音(tone burst,TB)刺激声分别对受试者进行皮层听觉诱发电位测试,并对人工耳蜗植入语前聋儿童进行婴幼儿有意义听觉整合量表或有意义听觉整合量表(infant-toddler meaningful auditory integration scale/meamingful auditory integration scale,IT-MAIS/MAIS)评分,比较两组P1波潜伏期,对P1波潜伏期和IT-MAIS/MAIS评分进行相关性分析。结果正常听力儿童四种不同频率短纯音刺激记录的CAEP P1波潜伏期与年龄均呈负相关(P<0.01);42月龄前植入人工耳蜗的语前聋儿童P1波潜伏期与正常听力儿童无统计学差异(P>0.05);42月龄以后植入人工耳蜗的语前聋儿童的P1波潜伏期较正常儿童显著延长,差异有显著统计学意义(P<0.01)。人工耳蜗植入儿童的CAEP P1波潜伏期与IT-MAIS/MAIS量表评分均呈负相关(P<0.01),不同频率TB刺激声下的P1波潜伏期无统计学差异(P>0.05)。结论大于42月龄植入人工耳蜗的语前聋儿童的中枢听觉系统发育较正常听力儿童延迟。

Central Auditory Development:Evidence from CAEP Measurements in the Congenitally Deaf Children after Cochlear Implants

Objective To study the development of the central auditory system of children who have received cochlear implants at different ages by recording the P1 latency in the cortical auditory evoked potential(CAEP).Methods The subjects included 50 congenitally deaf children who underwent cochlear implantation at different ages and 50 age-matched normal children.We recorded the P1 latency of the cortical auditory evoked potential in all subjects with tone burst(TB)of four different frequencies(500,1000,2000 and 4000 Hz)and used the IT-MAIS/MAIS scale to grade the congenitally deaf children after cochlear implantation.The changes of P1 latency in children with cochlear implantation was recorded,analyzed and compared with those in age-matched normal children.The correlation analysis was performed with the IT-MAIS/MAIS score.Results The P1 latencies in normal children were negatively correlated with age(P<0.01);there was no significant difference in P1 latency between the normal children and those congenitally deaf ones who underwent cochlear implantation before 42 months of age(P>0.05);while the P1 latencies of congenitally deaf children implanted after 42 months of age were significantly longer than that of normal children(P<0.01).There was negative correlation between the P1 latency of CAEP and the IT-MAIS/MAIS score(P<0.01).The P1 latency evoked by four different frequencies of tone burst showed no significant difference(P>0.05).Conclusion The developmental delay of central auditory system occurs when congenitally deaf children undergo cochlear implantation at ages older than 42 months.