先天性聋人工耳蜗植入儿童皮层听觉诱发电位的研究

Cortical auditory evoked potentials in congenital hearing impaired children with cochlear implants

目的 通过对先天性聋人工耳蜗植入儿童皮层听觉诱发电位（cortical auditory evoked potential,CAEP）的研究,探讨中枢听觉发育与人工耳蜗植入年龄之间的关系.方法 5岁前植入人工耳蜗的先天性聋患儿110例,测试时年龄12～80个月,其人工耳蜗使用时间从刚开机到48个月.声场下以65 dBSPL的/m/、/t/、/g/为测试声,进行CAEP测试,记录其P1、N1及P2波.分析各波的引出率、人工耳蜗植入年龄以及使用时间与P1波潜伏期的关系.结果 P1波的总体引出率为66.4％,N1波为15.5％,P2波为12.7％;P1波的引出率明显高于N1波（x^2=228.542,P=0.00）和P2波（x^2=257.438,P=0.00）,差异具有统计学意义./m/、/t/、/g/等三种刺激声的P1波引出率分别为64.1％、66.9％和68.3％,差异无统计学意义（x^2=0.589,P=0.75）;三种刺激声之间P1的潜伏期（P=0.22）和幅度（P=0.09）,差异均无统计学意义.植入年龄≤42月龄组P1潜伏期进入与年龄相当的正常值范围的百分比（95.3％）明显高于＞ 42月龄组（66.7％）,差异具有统计学意义（P=0.02）.在42月龄前植入人工耳蜗的儿童中,耳蜗使用时间分别为1年、2年、3年和4年的各组之间,在进入年龄相当的正常P1潜伏期范围的百分比上,差异无统计学意义（P=1.00）.结论 先天性聋患儿42月龄前植入人工耳蜗,其听觉中枢更有可能实现正常发育,而且一经植入使用,即可迅速发育达到正常听力的水平.

Objective By investigating the auditory cortical evoked potential in congenital hearing impaired children with cochlear implants,the association between central auditory development and the age of implantation was studied.Methods P1-N1-P2 were recorded in 110 profound hearing impaired children,aged from 12 to 80 months old and being implanted with cochlear implants before the age of 5 years.Their implant using time ranged from just at the switch-on to 48 months.The stimuli were /m/,/t/,/g/,presented at 65 dB SPL in sound field.The presence rate of each wave was obtained and the relationship between P1 latency and implant age,the time of speech processor switch-on were analyzed.Results The presence rate of P1,N1 and P2 was 66.4%,15.5% and 12.7%,respectively.The presence of P1 was significantly higher than that of N1 （x^2 =228.542,P =0.00） and P2 （x^2 =257.438,P =0.00）.There was no significant difference of P1 presence rate elicited by/m/,/t/ and /g/（64.1%,66.9% and 68.3%,x^2 =0.589,P =0.75）.There existed no significant difference either among P1 latency （P =0.22） or amplitude（P =0.09） elicited by/m/,/t/ and/g/.There was significant difference between the implant age before and after 42-month-old regarding the proportion that entered the age-appropriate normal P1 latency range（P =0.02）.No significant difference was found among groups of implant using time of 1,2,3 and 4 years in aspect of the proportion that entered the age-appropriate normal P1 latency range （P =1.00）.Conclusions Compared with implanted after the age of 42-month-old children with prelingual hearing impairment younger than 5 years old,the ones implanted before 42-month-old have more chance for normal development for central auditory system.Once implanted before 42-month-old,the cortical auditory system restored its normal development as early as 1 year after implantation.