脑干听觉诱发电位与中内耳CT三维重建对婴幼儿听觉通路结构及听力学异常的评估价值

Value of brainstem auditory evoked potential and 3-dimension spiral CT of middle and inner ear for the evaluation of abnormal audiology and the structure of auditory channels in infants

目的:脑干听觉诱发电位各波形反映相应神经核团的电活动,而中内耳三维CT重建可反映中内耳的结构发育情况,观察两者对婴幼儿听觉通路结构异常的评估价值。方法:选择2000-10/2003-05惠州市中心人民医院收治的耳聋患儿20例,年龄≤4岁,首先进行脑干听觉诱发电位检查,提示听觉通路下段异常然后以1.0mm层厚行双耳螺旋CT扫描并对中内耳结构行表面遮盖成像法三维重建,分析中耳听骨链及内耳结构的大小、形态及脑干听觉诱发电位图形中各波潜伏期,峰间潜伏期,波形的可重复性,波Ⅴ反应阈值。结果:纳入分析20例40只耳。①中内耳CT三维重建:20例40只耳中,显示中和/或内耳异常率42%(17/40),其中中耳听骨链异常12耳,表现为慢性中耳炎听骨链异常8耳(胆脂瘤型6耳,肉芽肿型2耳),表现为中耳听骨链异常4耳。内耳先天性发育异常5只耳(表现为半规管发育细小或不全3耳,耳蜗发育不全2耳)。余23只耳未见异常。②脑干听觉诱发电位检查:20例40耳脑干听觉诱发电位表现异常率82.5%(33/40):其中Ⅰ波缺失,余波正常13耳,Ⅰ～Ⅴ波潜伏期缺失20耳。结论:①脑干听觉诱发电位主要是通过短声刺激诱发脑干神经细胞产生电位记录,用于测试婴幼儿耳聋及高危儿,能客观地反映听力和听觉传导通路的病理障碍。②三维CT可更清楚地显示骨。

AIM:The electricity activity of vocality stimulation is evoked by wave forms of brain stem auditory evoked potentia; the reconstruction of 3 dimension spiral CT can display the structure of auditory channels.The study was to observe the value in evaluating the normal structure of auditory channels of infants. METHODS:A total of 40 infants(≤ 4 years of age) with deafness were selected from Huizhou Center People's Hospital from October 2000 to May 2003.Brain stem auditory evoked potential displayed abnormal extracranial auditory channels.Patients received double ears spiral CT scan and reconstruction of 3 dimension spiral CT with 1.0 mm in middle and inner ear to analyze the size and form of ossicular chain of middle ear and structure of inner ear,latent period of wave forms,interpeak latency,reproducibility of wave forms, response threshold of Ⅴ wave in brain stem auditory evoked potential.RESULTS:A total of 20 patients with 40 ears were involved in the result analysis.① 3 dimension spiral CT of middle and inner ear:in 40 ears of 20 cases, abnormal ears was 42% (17/40).Among them,12 ears showed abnormal ossicular chain of inner ear,8 of the 12 ears suffered from chronic tympanitis including 6 cholesteatoma and 2 granuloma, and the other 4 ears suffered from innate abnormal ossicular chain of inner ear; innate abnormal development was showed in 5 ears,among which,3 ears suffered from emicircular canal abnormal development,and 3 ears suffered from cochleae dysgenesis.No abnormal was found in another 23 ears.② Brain stem auditory evoked potential: 40 ears of 20 cases showed abnormal[(82.5% (33/40)],among which,13 ears showed missed Ⅰ wave and others waves were normal,and 20 ears showed missed latent period of Ⅰ - Ⅴ waves. CONCLUSION:① Brain stem auditory evoked potential induces brain stem cells to record the potential by short sound stimulation for detecting the infant deafness and high risk infants,which can reflect the pathological impediment of audile and auditory channels .② 3 dimension spiral CT can reflect the anatomic structure of bone,anvil and its joints,observe the 3 dimension spatial relationship of anatomic structure,so as to increase the veracity in diagnosing the abnormal audile due to auditory ossicle lesion,etc.