【作者】 贺湘波；

【导师】 谢鼎华；

【作者基本信息】 中南大学 ， 外科学， 2012， 博士

【摘要】 第一部分内耳结构正常与异常的极重度感音神经性聋患者的影像学评估目的探讨高分辨率CT和MRI在内耳结构异常的极重度感音神经性聋患者中的诊断价值。资料与方法对386例申请人工耳蜗植入的先天性感音神经性耳聋儿童患者进行颞骨高分辨率CT和MRI检查,总结内耳结构异常患者的影像学资料以便选择适合的人工耳蜗接受者和植入耳侧。对于大前庭水管综合征患者和对照组,在CT图像上测量前庭水管中点最宽径及外口直径,在MRI图像上测量内淋巴囊骨内段部分中点及外口直径。对耳蜗转位组患者和对照组分别测量：①耳蜗底转平面和头部正中矢状面的夹角((?)α)；②面神经垂直段中心和圆窗龛上缘的连线与头部正中矢状面的夹角((?)β)；③圆窗平面中,面神经垂直段表面到外耳道后壁的垂直距离A。各组间CT或MRI测得的数据差异行t检验。结果45例内耳结构异常患者中有大前庭水管综合征30例,CT显示扩大的前庭水管,MRI显示扩大的内淋巴囊,与正常人有显著性差异。3例耳蜗转位畸形患者的(?)β值大于对照组,而且(?)α<(?)β。此外还发现4例Mondini畸形,2例不完全分隔Ⅰ型,1例Michel畸形,1例内听道狭窄及听神经发育不良,1例前庭畸形合(?)内听道底缺损,3例耳蜗骨化。结论MRI在大前庭水管综合征、耳蜗骨化及听神经发育不良的诊断方面比CT更具优越性。测量耳蜗底转平面和头部正中矢状面的夹角((?)α)和面神经垂直段中心和圆窗龛上缘的连线与头部正中矢状面的夹角((?)β),可用于评估耳蜗位置并有助于术中准确实施耳蜗开窗。CT及MRI对诊断内耳畸形具有各自的优点,结合两种方法为临床人工耳蜗植入提供了良好的保障。第二部分内耳畸形和结构正常的极重度感音神经性聋患者的分子病因研究研究目的对申请人工耳蜗植入的耳聋患儿进行GJB2、SLC26A4、线粒体12SrRNA基因突变的检测,探讨中国人极重度非综合征性聋患者的分子病因以及适合中国人的耳聋基因诊断策略。通过比较内耳结构正常和内耳畸形患者中常见致聋基因的基因型,探讨内耳畸形的遗传学病因。研究方法采集278名申请人工耳蜗植入的极重度感音神经性耳聋患者,其中有内耳畸形患者42例。对照组为100例听力正常者。提取所有受检者的基因组DNA,用耳聋基因芯片检测四个国人中常见的耳聋相关基因中的9个热点突变,包括GJB2(35delG、176del16bp、235delC及299delAT)、GJB3(538C>T)、SLC26A4(IVS7-2A>G、2168A>G)和线粒体DNA12SrRNA (1494CT、1555A>G)。然后用传统测序法对基因芯片检测结果进行验证。对基因芯片检测未发现突变或发现GJB2基因单杂合突变的患者行GJB2基因测序；对发现SLC26A4单杂合突变的患者分别行SLC26A4基因的测序。研究结果经测序的方法278例患者中发现98例携带有GJB2基因突变,阳性突变检出率约37.05%。测序法同应用基因芯片检测的结果一致,后者的阳性突变检出率为20.50%。两种方法对GJB2携带者的检出率有显著性差异。278例患者GJB2致病等位基因频率合计为29.32%(163/556)。共发现5种常见多态,10种已报道的致病突变。而其中235delC是最常见的致病突变类型,其次为109G>A,然后为299delAT。内耳结构正常组33.90%(160/472)患者发现GJB2基因致病突变,内耳结构异常组的GJB2基因等位基因突变频率7.14%(6/84),与正常听力对照组无显著差异。说明GJB2基因突变不是内耳畸形的主要病因。本研究发现极重度感音神经性聋患者线粒体DNA12SrRNA1494C>T及1555A>G突变检出率为分别为0.36%(1/278)及3.24%(9/278)。未发现1例GJB3(538CT)患者。在278名极重度感音神经性聋患者中,基因芯片检测出26例具有SLC26A4基因IVS7-2A>G和/或2168A>G的突变,其中25例为大前庭水管综合征患者。经过测序发现在30名大前庭水管综合征患者中,有28例携带有SLC26A4基因突变,发生率约93.33%。大前庭水管综合征患者组中,基因芯片对SLC26A4基因突变检出率为83.33%。测序法与基因芯片法比较,对SLC26A4基因检出率的差异无统计学意义。在本实验中共发现了16种SLC26A4突变类型,其中4种为新的突变类型(G368X, IVS8-1G>T, IVS13+9CT和Q696X)。在所有的突变中,IVS7-2A>G突变的发生率最高,其次为H723R和T410M。结论耳聋基因芯片适用于遗传性耳聋基因筛查。根据基因芯片快速检测结果,并结合相应基因的测序能很好地诊断极重度聋的分子病因。278例极重度聋患者中GJB2基因突变阳性检出率约28.24%,但GJB2基因突变不是内耳畸形的主要病因。SLC26A4基因突变是大前庭水管综合征的主要病因,本地区患者中IVS7-2A>G突变的发生率最高,其次为H723R和T410M。新发现的4种突变类型对于大前庭水管综合征的诊断和病因研究具有重要意义。第三部分内耳结构异常的极重度感音神经性患者的人工耳蜗植入研究目的探讨先天性内耳结构异常的极重度感音神经性聋患者行人工耳蜗植入的方法及其问题与对策。研究方法对2006-2011年在中南大学湘雅二医院中请行人工耳蜗植入的伴有内耳结构异常的45例极重度感音神经性耳聋患者进行回顾性分析。将伴有内耳结构异常的患者的耳科学和影像学资料,人工耳蜗植入手术要点,术后康复效果进行总结。研究结果45例内耳结构异常的患者中最常见的类型为大前庭水管综合征、耳蜗不全分隔Ⅱ型和耳蜗骨化。36例内耳结构异常患者接受了人工耳蜗植入,除1例耳蜗转位患者术中未能植入电极外,其余35人均成功植入电极。30例大前庭水管综合征患者术中开窗时出现外淋巴液波动；2例Mondini畸形患者行耳蜗开窗时出现脑脊液“井喷”。将电极插入耳蜗后用备好的筋膜和肌肉组织行前庭和耳蜗填塞并封闭开窗口,结合耳脑胶封闭,能有效控制脑脊液流出,术后恢复良好。35例成功接受人工耳蜗植入术的患者均无严重并发症,术后听力及言语康复效果良好。结论伴有轻度内耳结构异常的极重度感音性聋患者可以行人工耳蜗植入手术,与耳蜗结构正常患者的人工耳蜗植入效果基本一致。术前详细的影像学和听力学评估以及术中正确规范的处理是手术成功的基本条件。更多还原

【Abstract】 Part I Image assessments in the patients with normal or abnormal inner ear and profound sensorineural hearing lossObjectiveTo discuss the value of high resolution computer tomography (HRCT) and magnetic resonance imaging (MRI) in children with abnormal inner ear and profound sensorineural hearing loss.Materials and MethodsHRCT and MRI were performed in386cochlear implantation (CI) applicants with congenital sensorineural hearing loss. The results were analyzed in order to select suitable cases and ears for cochlear implantation. For the cases with enlarged vestibular aqueduct and the control group, the largest diameter of the midpoint of vestibular aqueduct (VA) and the external aperture were measured on CT scan image, respectively. Meanwhile, the largest diameter of the midpoint and the external aperture of the bony part of endolymphatic sac (ES) were measured on MRI image. The normal children group, the normal cochlear position group and the cochlear position malformation group measured3parameters respectively:①the angle of the basal turn of the cochlea relative to the sagittal plane (∠α);②the angle of line from the vertical portion of facial nerve to round window niche relative to the sagittal plane (∠β);③the vertical distance from the vertical portion of facial nerve to the posterior wall of external auditory canal at the level of round window (Distance A). The data obtained from CT and MRI were statistically analyzed by correlation test and t test.ResultsForty-five cases had inner ear anomalies, the remaining341cases had no any anomalies. In total of45cases,30cases with enlarged vestibular aqueduct showed by CT and MRI. Three cases were found to be with cochlear rotation,∠β of3cases of the cochlear position malformation group all exceed the upper limit of reference range. We found that∠α>∠β in the normal children group and the normal cochlear position group, by contrast,∠α<∠β in the cochlear position malformation group.Four patients were found to be with Mondini dysplasia, two with incomplete partition I, one with stenosis of internal auditory canal, one with vestibules malformations and defect of internal auditory canal bottom, three with cochlear ossification.ConclusionAccurate diagnosis of enlarged vestibular aqueduct syndrome, cochlear ossification and cochlear nerve dysplasia could be detected with MRI.∠α and∠β can be used to assess the cochlear position and help to open cochlear correctly in cochlear implantation. HRCT and MRI were complementary and helpful in surgical treatment planning and prognosis predicting. MRI was important in the evaluation of auditory nerve. Preoperative detailed radiological evaluations are essential factors for the successful operation. Part II Molecular epidemiology in the patients with abnormal or normal inner ear and profound sensorineural hearing lossObjectiveTo explore the molecular epidemiology and effective genetic diagnostic method for the Chinese patients with nonsyndromic sensorineural hearing loss (NSHL), we reported our result of genetic examination based on DNA Microarray combining with DNA sequencing in the cochlear implantation (CI) applicants from China. A comparison of genotype between the cases with abnormal inner ear and the cases with normal inner ear was made to find the genetic cause of inner ear malformation.Methods278CI applicants with profound NSHL from our department, including42casess with malformation of inner ear, underwent genetic examination in our research. Genomic DNA from100health individuals was used as control group. The molecular pathogenesis of NSHL was analyzed with the DNA microarray which is able to perform mutation detection of9hot-spot mutations in4prevalent deaf-causing genes, including GJB2(35delG,176dell6bp,235delC and299delAT), GJB3(538C>T), SLC26A4(IVS7-2A>G,2168A>G) and mtDNA12SrRNA (1494C>T and1555A>G). Subsequently the results were confirmed with PCR and DNA sequencing. We stopped the examining process if homozygous or composite heterotic mutations were detected through DNA microarray, otherwise we examined the other exons until another mutation was found or examined all the rest exons.Results20.50%(57/278) of CI applicants were detected to have mutations in GJB2gene with DNA microarray. When DNA microarray combining with direct sequencing was applied,35.25%(98/278) cases were detected to have GJB2mutations. The difference between the two methods was statistically significant. Only11.90%(5/42) patients with inner ear malformation were detected to have GJB2mutations. The incidence of GJB2mutations in the278patients with NSHL is28.24%. The incidence of GJB2mutations of the NSHL patients with normal inner ears is28.24%, and it is5.95%in the cases with abnormal inner ears. The difference of the incidence in the NSHL patients between the group of abnormal inner ears and the control group was not statistically significant. A total of5polymorphism and10mutations of GJB2were detected in our research. The235delC is the most prevalent mutation detected, followed by109G>A and299delAT.9patients were found to carry mtDNA A1555G mutation and one found to carry1494C>T among278CI applicant.26cases were found to have SLC26A4mutation among278CI applicants with DNA microarray. Among30patients with large vestibular aqueduct,28cases were found to have mutations in SLC26A4gene with PCR and direct sequencing. A total of16SLC26A4mutations were identified in the study, including4novel mutations (G368X、 IVS8-1G>T、IVS13+9C>T and Q696X). IVS7-2A>G was the most common mutation in Chinese, H723R and T410M were also common.Conclusions DNA microarray can be used to generally screen hot spot mutation of common genes in CI applicants with profound hearing loss. DNA microarray combining with direct sequencing analysis allows us to get accurate outcome in the genetic examination on a large scale. The incidence of GJB2mutations of the NSHL patients with normal inner ears is28.24%. The GJB2mutation is not the main cause of malformation of inner ear. IVS7-2A>G is the most prevalent SLC26A4mutation in Chinese patients with EVAS, followed by H723R and T410M. The4novel mutations found in our research could further our understanding of the cause for EVAS and improve diagnostics method for EVAS. Part III Cochlear implantation in the patients with abnormal inner ear and profound sensorineural hearing lossObjectiveTo evaluate the outcome and complications encountered in the patients with anomalous inner ear who underwent cochlear implantation.MethodRetrospective analyses included45patients with anomalous inner ear and profound sensorineural hearing loss who applied for cochlear implant at the Second Xiangya Hospital of Central South University from2006to2011. Fifty NSHL patients with normal inner ear were used as controls. To explore effective methods for the diagnosis and treatment of inner ear malformation, we summarize the radiological and otological evaluation, treatment and outcome of cochlear implantation in the cases.Results The most common inner ear malformation we found were enlarged vestibular aqueduct (EVA), incomplete partition Ⅱ (Mondini dysplasia), and cochlear ossification. Thirty-six patients with abnormal inner ear underwent cochlear implantation, of this number,30patients presented EVA,2patients with incomplete partition Ⅱ,3with cochlear rotation and1with cochlear ossification. The electrodes were fully inserted into the scale tympani of the cochlea in35cases except for1case with cochlear rotation. Perilymphatic/cerebrospinal fluid fluctuation occurred in30cases with EVA during the implantation. Leakage of cerebral spinal fluid (Gusher) occurred in2patients with Mondini dysplasia. They were controlled by inserting the electrode array and sealing the vestibule and cochlea with temporal fascia or muscle. None of the recipients developed severe complications after implantation. We achieved an electrical stimulation of the neural elements in35cases who received implantation successfully.Conclusions No differences were found between patients with normal cochleas and those with minor malformations such as enlarged vestibular aqueduct and incomplete partition. Comprehensive pre-operative radiographic and audiological evaluation and intraoperative exactly performing are essential factors of the successful operation.更多还原