A new classification for cochleovestibular malformations
A new classification for cochleovestibular malformations
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DOI：
10.1097/00005537-200212000-00019
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发表时间：
2002-12-01
期刊：
影响因子：
2.6
通讯作者：
Saatci, I
中科院分区：
文献类型：
--
作者：
Sennaroglu, L;Saatci, I
目的：根据23例内耳畸形的放射学特征，提出一种新的内耳畸形分类系统。研究设计：对23例内耳畸形患者(男13例，女10例)的颞骨CT结果进行回顾性分析。受试者均为双侧严重感音神经性聋患者，均行高分辨率CT扫描，轴位经岩骨获得1 mm厚的连续图像。方法：回顾分析耳蜗型、前庭型、半规管型、内耳道型、前庭型及耳蜗型骨性耳囊畸形的CT表现。耳蜗术后畸形分为Michel畸形、共腔畸形、耳蜗性发育不全、发育不良、不完全分隔I型(IP-I)和II(IP-II)(Mondini畸形)。不完全分隔型I型(囊性耳蜗前庭畸形)是指耳蜗区缺乏整个蜗壳和筛状区，导致囊性外观，并伴有大的囊性前庭的畸形。在IP-II(Mondini畸形)中，有一个由1.5圈组成的耳蜗(其中中圈和尖圈合并形成一个囊状尖端)，并伴有扩张的前庭和扩大的前庭导水管。结果：4例患者表现为仅累及一个内耳的畸形。其余所有患者都有影响一个以上内耳部件的疾病或状况。IP-I 8耳，IP-II 10耳。IP-I患者的耳朵有较大的囊性前庭，而IP-II患者的扩张量最小。大部分半规管(67%)正常。半规管发育不全合并Michel畸形、耳蜗管发育不良、共同空洞等。14耳IAC外侧端眼底有缺陷。在两只耳朵中，IAC缺席。在7例常见空洞畸形中，IAC外侧端均有骨缺损。其中5例IAC扩大，2例IAC狭窄。所有IP-I患者的IAC增大，而在II型疾病患者中，4例IAC正常，10例IAC增大。所有的IP-II病例都有扩大的前庭导水管，而IP-I的病例中没有任何一例出现这种发现。在所有病例中，前庭导水管的发现在两侧对称(同时正常或扩大)。没有患者表现出耳蜗管扩大或任何其他异常。结论：本研究中先天畸形的放射学表现提示两种不同类型的不完全分隔。囊性耳蜗前庭畸形(IP-I)和经典型Mondini畸形(IP-II)。I型畸形的分化程度低于II型畸形。典型的Mondini畸形有三个组成部分(囊状尖部、扩张的前庭和大的前庭导水管)，而I型畸形有一个空的囊状耳蜗和前庭，没有扩大的前庭导水管。Mondini畸形是一种较晚的畸形，因此其发育不良的数量远少于II型。因此，将这些畸形按严重程度从大到小依次分类为Michel畸形、耳蜗性发育不全、共同腔畸形、IP-I(囊性耳蜗性前庭畸形)、耳蜗性发育不良和IP-Il(Mondini畸形)更为准确和实用。只有这样，才能对这些复杂的畸形进行准确的分组，并与人工耳蜗术的结果进行比较。
Objective: The report proposes a new classification system for inner ear malformations, based on radiological features of inner ear malformations reviewed in 23 patients. Study Design: The investigation took the form of a retrospective review of computerized tomography findings relating to the temporal bone in 23 patients (13 male and 10 female patients) with inner ear malformations. The subjects were patients with profound bilateral sensorineural hearing loss who had all had high-resolution computed tomography (CT) with contiguous 1-mm-thick images obtained through the petrous bone in axial sections. Methods: The CT results were reviewed for malformations of bony otic capsule under the following subgroups: cochlear, vestibular, semicircular canal, internal auditory canal (IAC), and vestibular and cochlear aqueduct malformations. Cochlear malformations were classified as Michel deformity, common cavity deformity, cochlear aplasia, hypoplastic cochlea, incomplete partition types I (IP-I) and II (IP-II) (Mondini deformity). Incomplete partition type I (cystic cochleovestibular malformation) is defined as a malformation in which the cochlea lacks the entire modiolus and cribriform area, resulting in a cystic appearance, and there is an accompanying large cystic vestibule. In IP-II (the Mondini deformity), there is a cochlea consisting of 1.5 turns (in which the middle and apical turns coalesce to form a cystic apex) accompanied by a dilated vestibule and enlarged vestibular aqueduct. Results: Four patients demonstrated anomalies involving only one inner ear component. All the remaining patients had diseases or conditions affecting more than one inner ear component. Eight ears had IP-I, and 10 patients had IP-II. Ears with IP-I had large cystic vestibules, whereas the amount of dilation was minimal in patients with IP-II. The majority of the semicircular canals (67%) were normal. Semicircular canal aplasia accompanied cases of Michel deformity, cochlear hypoplasia, and common cavity. In 14 ears, the IAC had a defective fundus at the lateral end. In two ears the IAC was absent. In all seven cases of common cavity malformations, there was a bony defect at the lateral end of the IAC. In five of them the IAC was enlarged, whereas in two the IAC was narrow. All patients with IP-I had an enlarged IAC, whereas in patients with type II disease, four had a normal IAC and 10 had an enlarged IAC. All cases of IP-II had an enlarged vestibular aqueduct, whereas this finding was not present in any of the cases of IP-I. In all cases, the vestibular aqueduct findings were symmetrical on both sides (simultaneously normal or enlarged). No patient demonstrated enlargement or any other abnormalities involving the cochlear aqueduct. Conclusions: Radiological findings of congenital malformations in the present study suggested two different types of incomplete partition. Cystic cochleovestibular malformation (IP-I) and the classic Mondini deformity (IP-II). The type I malformation is less differentiated than the type II malformation. Classic Mondini deformity has three components (a cystic apex, dilated vestibule, and large vestibular aqueduct), whereas type I malformation has an empty, cystic cochlea and vestibule without an enlarged vestibular aqueduct. Mondini deformity represents a later malformation, so the amount of dysplasia is much less than in type II.Therefore, it is more accurate and useful for clinical purposes to classify these malformations (in descending order of severity) as follows: Michel deformity, cochlear aplasia, common cavity, IP-I (cystic cochleovestibular malformation), cochlear hypoplasia, and IP-Il (Mondini deformity). Only in this way can these complex malformations be grouped precisely and the results of cochlear implantation compared.