大前庭水管综合征患者误诊与漏诊原因分析

Causes of misdiagnosis and Missed diagnosis in patients with large vestibular aqueduct syndrome(LVAS)

目的了解大前庭水管综合征(large vestibular aqueduct syndrome,LVAS)患者的临床特征,分析造成误诊和漏诊的原因。方法观察19例被误诊或漏诊的LVAS患者,详细了解诊治经历,行纯音测听、声导抗测听及脑干诱发电位等听功能检查,所有患者均行颞骨高分辨CT检查。结果 19例患者确诊年龄为8.34±8.09岁,而最初发现听力下降的年龄为1.69±1.42岁。本组患者曾被误诊为感音神经性耳聋10例、混合性聋3例、梅尼埃病2例,另4例没有注意到听力障碍而被漏诊。年龄>6岁患者7例(14耳)纯音测听平均听阈为84.5±12.8dB nHL,其中7耳低频区存在骨-气导差;年龄≤6岁患者12例(22耳)进行ABR检查显示客观听阈平均为67.81±18.53dB nHL。颞骨高分辨CT检查显示前庭水管中点宽度全部36耳平均为3.96±1.36mm,其中32耳前庭水管与半规管总脚相通、10耳与前庭相通,23耳合并mondini畸型。结论对于难以解释的儿童波动性感音神经性听力损失、混合性听力损失及平衡功能障碍的患者,颞骨高分辨CT检查应该作为常规检查。

Objective To summarize clinical characteristics of patients suffering from large vestibular aqueduct syndrome （LVAS） and analyze possible reasons for misdiagnosis and missed diagnosis. Methods Nineteen cases of misdiagnosed or unrecognized LVAS were included in this study. Clinical histories, pure tone audiometry, immittance audiometry,auditory brainstem response （ABR）, and high resolution CT （HRCT） image of temporal bone were reviewed in each case. Results The mean age at diagnosis in the 19 patients was 8.34 ± 8.09 years, although the mean age of hearing loss onset was 1.69 ±1.42 years. Among the 19 patients, 10 were misdiagnosed for sensorinearal deafness, 3 for mixed deafness, 2 for Meniere＇ s disease, and 4 were not diagnosed because hearing loss was ignored by their parents. Seven patients （14 ears）were older than 6 years and their mean hearing level was 84.5±12.8 dB nHL on pure tone audiometry, Among them, air bone gap existed in low frequencies in 7 ears. Twelve patients （22 ears） were six 6 years old or younger, and their mean hearing level was 67.81±18.53 dB nHL on ABR. In all 36 ears, mean width of the vestibular aqueduct was 3.96± 1.36 mm.The vestibular aqueduct communicated with the common crus in 32 ears and with the vestibule in 10 ears. Mondini＇s deformity was seen in 23 ears. Conclusion To avoid missed diagnosis of LVAS, HRCT should be adopted as a routine examination for children who have unaccountable fluctuant sensorineural or mixed hearing loss or equilibrium disorders