蜗神经发育不良儿童的临床特征分析

目的探讨蜗神经发育不良(cochlear nerve deficiency,CND)儿童的临床特征。方法以43例(60耳)CND患儿(4个月~10岁,平均2.6±2.8岁)为研究对象,总结分析其是否存在听力损失高危因素、影像学检查及听性脑干反应(ABR)、畸变产物耳声发射(DPOAE)、Chirp声诱发听性稳态反应(Chirp-ASSR)检测等结果。结果43例患儿中,26例(60.5%,26/43)为单侧病变,17例(39.5%,17/43)为双侧病变;仅7例患儿有听力损失高危因素。50耳(83.3%,50/60)为蜗神经缺如,10耳(16.7%,10/60)为蜗神经细小;16耳(26.7%,16/60)伴面神经细小,8耳(13.3%,8/60)伴前庭神经异常。4耳(6.7%,4/60)仅伴前庭畸形为第一组,21耳(35%,21/60)合并耳蜗畸形或同时合并前庭畸形为第二组,35耳(58.3%,35/60)不伴内耳畸形为第三组。26耳(43.3%,26/60)ABR仅见波Ⅲ以前波形分化,随后波形消失;23耳(38.3%,23/60)ABR无波形分化;11耳(18.3%,11/60)可见分化不良的波V,其反应阈值为75~100 dB nHL。24耳(40%,24/60)DPOAE或/和CM引出,且第三组CND患儿DPOAE的信噪比(SNR)值和引出率均明显高于CND合并内耳畸形的第一、二组患儿。49耳ABR最大声输出时未引出波V的CND患儿中,41耳(83.7%,41/49)Chirp-ASSR可在不同频率不同程度引出,500、1000、2000和4000 Hz Chirp-ASSR平均反应阈分别为87.14±21.33、89.27±16.09、89.37±15.85和91.10±15.77 dB corHL。结论本组CND患儿多无明确听力损失高危因素或病因,多表现为重度或极重度感音神经性聋,高发于先天性单侧感音神经性聋婴幼儿,可表现出听神经病的特征,ABR仅见波III以前波形分化,随后波形消失,Chirp-ASSR测得残余听力明显优于ABR检测结果。

Clinical Characteristics in Children with Cochlear Nerve Dysplasia

Objective To investigate the clinical features of cochlear nerve dysplasia in children(cochlear nerve deficiency,CND).Methods The clinical data of 43 children(60 ears)with CND were analyzed retrospectively.The epidemiological,imaging and audiological results were summarized.Results Epidemiology:60.5%(26/43)of children had unilateral lesions and 39.5%(17/43)of children had bilateral lesions,only 7 children had high risk factors of hearing impairment,and the rest had no obvious high risk factors of hearing impairment.Imaging:83.3%(50/60)of cases showed cochlear nerve absence,16.7%(11/60)of cases showed cochlear nerve parenchyma,26.7%(16/60)of cases showed with facial nerve parenchyma,and 13.3%(8/60)of cases showed with atrium nerve abnormality.According to whether the inner ear malformation was complicated or not,all patients were divided into three groups:6.7%(4/60)with vestibular malformation as the first group,35%(21/60)with cochlear malformation or simultaneous vestibular malformation as the second group,and 58.3%(35/60)with CND alone without inner ear malformation as the third group.Audiology:three abnormal results could be obtained by ABR:43.3%(26/60)ABR showed III wave differentiation before wave,and then the waveform disappeared into the first kind;38.3%(23/60)ABR was flat(no waveform differentiation),18.3%(11/60)showed poorly differentiated V wave,and the reaction threshold was the third in the range of(75~100)dBnHL.DPOAE and CM:40%(24/60)DPOAE or/and CM were introduced,and the SNR value and extraction rate of DPOAE in the third group of CND were significantly higher than those in the first group and the second group of CND complicated with inner ear malformation.ASSR:In 49 CND children whose response threshold V was not induced at the maximum sound output of ABR,83.7%(41/49)could be induced at different frequencies and in different degrees in Chirp-ASSR.The average response threshold of ASSR in 500,1000,2000 and 4000 Hz was 87.14±21.33,89.27±16.09,89.37±15.85 and 91.10±15.77 dB corHL,respectively.The response thresholds were significantly lower than those in patients with very severe acoustic nerve deafness who were negative in both temporal bone CT and inner ear MRI.The difference was statistically significant(P<0.05).Conclusion CND is a disease with unique clinical characteristics that can cause severe sensorineural deafness.In addition to paying attention to the"gold standard"of inner ear MRI examination,the important reference value of objective electrophysiological audiometric examination should not be ignored for the diagnosis and intervention decision of CND in children.