听神经发育不良患者人工耳蜗植入术后效果的研究

It has been found that 2.5-21.2% patients of congenital sensorineural deafness were diagnosed as cochlear nerve deficiency(CND), which used to be regarded as a relative contraindication of cochlear implantation. Studies found that most CND patients benefited from cochlear surgery, but still some patients had no auditory response after years wearing the cochlear. CND is thought to diminish development of auditory perception with CI because of a small number of SGNs, the target for implant-mediated electrical stimulation. Theoretically, the counts of SGNs relate to the size of the cochlear nerve; however, accurate measurement of the diameter of the cochlear nerve is sometimes not visualized on conventional MRI. Our previous study has found that the auditory and speech abilities after CI in CND patients are related to the imaging of the nerves in the internal acoustic meatus in 3D-MRI . This project intends to adjust the imaging parameters, display the fine structure, measure the diameter of internal auditory canal and the situation of the nerves in the internal acoustic meatus, then further analyze the relationship between imaging measurement data and the patients’ auditory and speech ability after cochlear implantation, establish standardized assessment system for patients of CND, finally using the preoperative audiology and imaging evaluation to predict the postoperative results of the patients with CND. The results will not only help the surgeon make a better choice of implant side , but also advice the postoperative auditory speech rehabilitation training, in all, offer the patients the maximize benefits of cochlear implantation.

先天性感音神经性聋患者中2.5-21.2%存在听神经发育不良（CND），CND患者是否行人工耳蜗植入术（CI）尚缺乏统一规范，大多数CND患者在CI术后受益，但部分患者佩戴耳蜗多年仍无听觉反应。研究认为CND患者CI术后效果较差与其缺失部分螺旋神经节细胞相关，这一缺失在影像学最直接的表现是蜗神经直径的减小，但其在传统MRI上可能显示不清。本课题组前期研究发现，术前3D-MRI显示内听道底仅一个神经点的CND患者与显示两点神经的组相比，术后听觉言语效果明显较差。本项目拟调整和细化影像学技术参数，显示微小结构，进一步研究颞骨HRCT上内听道及蜗孔的直径、 3D-MRI斜矢状位内听道底神经的点数及直径，与CI术后听觉言语能力的相关性，建立规范化的CND患者CI术前评估体系，最终根据术前听力及影像学评估来预测术后效果，这样不仅能指导临床选择CI手术的侧别，还能为术后康复提供建议，使患者收益最大化。

先天性感音神经性聋患者中2.5-21.2%存在听神经发育不良（Cochlear nerve deficiency, CND），CND患者是否行人工耳蜗植入术（Cochlear implantation, CI）尚缺乏统一规范，大多数CND患者在CI术后受益，但部分患者佩戴耳蜗多年仍无听觉反应。CND是否行CI主要依靠临床医师的个人经验，选择差异大，缺少规范化治疗标准。CND的诊断影像学最直接的表现是蜗神经直径的减小，但其在传统核磁上可能显示不清。本研究探究CND患者与非CND患者术后效果的差异，同时探究CND患者术前影像学数据与CI术后听觉言语效果的相关性，建立规范化的CND患者CI术前评估体系。. 研究截止目前共纳入228例CND的患者并配对匹配正常对照组，发现其中伴有内耳畸形的占110例（48.25%），包括耳蜗分隔不全I、II、III型，共同腔畸形、耳蜗发育不全、囊状耳蜗等，不伴内耳畸形的118例，占51.75%。统计分析患者人口学信息、影像测量指标和术后效果的关系，影像测量数据包括内听道及骨性蜗神经管的直径，内听道底神经的点数及及在桥小脑角处前庭蜗神经及面神经面积，术后效果评估主要使用言语评估量表CAP、SIR、 MAIS /IT-MAIS 和MUSS。结果发现CND组患者较非CND组患者的CI术后效果差，伴有内耳畸形的CND较不伴有内耳畸形的效果差；长期效果随访发现CND患者较非CND听觉言语效果进展更加缓慢，但听觉效果较言语效果发育好；植入年龄与术后效果分析显示，植入初期植入年龄越大效果增长越快，后期这种优势逐渐减弱，越小植入随着佩戴时间的增长发育越好。影像与术后效果相关性显示神经点数、骨性蜗神经管的直径、内耳道的直径、前庭蜗神经的面积和VCN与FN的面积比与CI术后效果呈正相关，其中神经点数和前庭蜗神经面积对术后效果的预测效果最强。. 本研究发现某些内听道内不存在听神经的患者亦可从CI手术获益，提示我们目前的影像可能无法发现某些纤细的神经束，此时可通过桥小脑角区及颅内的神经分布情况来预测效果。另外神经结构的发育与CND患者CI术后效果密切相关，术前应根据神经发育情况选择此类患者的侧别，帮助患者获得最大收益。