舌下神经修复面神经损伤的中枢神经系统可塑性机制研究

Facial nerve injury, which can occur in temporal bone and cerebellopontine angle surgeries, trauma and neoplasms, results in facial palsy and a subsequent loss of facial symmetry and expression that have a great psychosocial impact on patients. In previous studies, our results have shown that hypoglossal-facial nerve "side"-to-side anastomisis using a pre-degenerated auto-graft, which may retain the remnants of the facial axons and as conserve partial hypoglossal nerve (approximately 50%), can effectively treat peripheral facial palsy resulting from facial nerve injury. Recent years, the clinical investigation of functional magnetic resonance imaging (fMRI) has shown that the facial muscle movements are related to the special areas of the cerebral cortexe in normal condition. However, it is not yet well known the mechanisms and potential capability of functional reorganization and structure reconstruction after facial nerve injury and its repair by hypoglossal motoneurons. The present project is designed to treat the patients who have suffered from the facial palsy due to injury with anatomical conservation of facial nerve after removral of CPA neoplasms. The treatment consists of the hypoglossal-facial nerve "side"-to-side anastomosis combined with a well-designed individualized postoperative rehabilitation training. With Functional Magnetic Resonance Imaging (fMRI) technique including the rest-state fMRI, the task-state fMRI, and the voxel-based morphometry(VBM) technique as well as the diffusion tensor image(DTI), we will investigate the cerebral cortex network and special activity areas that control the facial movements in order to understand the functional reorganization mechanisms and potential plasticity of central nervous system. Moreover, we intend to establish a relevant model with symptom course, clinical and electrophysiological assessments as well as cortical reconstruction imaging during the recovery of facial nerve function. We hope that this study may provide useful information for treatment of facial paralysis due to FN injury, thus providing a proof-of-feasibility for further clinical application.

临床上颅底肿瘤患者常因肿瘤侵袭或手术牵拉而导致面神经损伤，所造成的面瘫严重影响患者生活质量，其治疗一直是神经外科领域备受关注的热点。本课题组前期采用预变性的自体腓肠神经桥接舌下神经和面神经，行"侧"-侧吻合术，已从临床和电生理学检查方面验证了其修复周围性面瘫的有效性。近年来利用功能核磁共振技术已明确正常人群的面部运动相关脑区，但面神经损伤应用部分舌下神经纤维修复后大脑皮层功能重组及结构重塑的机制以及面部功能修复的能力仍有待进一步探讨。本研究拟通过对桥脑小脑角区肿瘤切除术后面瘫患者进行改良吻合手术及开展术后有目的性的康复训练，利用静息态、任务态功能核磁共振，结合基于体素的形态学测量技术、弥散张量成像技术来探讨这种异位神经元修复面神经后相关中枢运动网络的可塑性机制及相关功能的转换能力；并建立面神经损伤及修复过程中，损伤时间-临床症状-电生理改变-大脑皮层重塑之间的相关性模型。

1.背景：临床上颅底肿瘤患者常因肿瘤侵袭或手术牵拉，术中出血电凝等原因而导致面神经损伤，所造成的面瘫严重影响患者生活质量和心理健康，其治疗一直是神经外科医生关注的焦点。本课题组前期采用预变性的自体腓肠神经桥接舌下神经和面神经，行“侧”-侧吻合术，已验证其修复周围性面瘫的有效性。近年来利用功能核磁共振技术已明确正常人群的面部运动相关脑区，但面神经功能受损和修复后大脑皮层功能重组及结构重塑的机制仍未阐明。.2.研究内容：本研究拟通过对桥脑小脑角（CPA）区肿瘤切除术后面瘫患者进行面神经修复手术及术后针对性康复训练，利用静息态、任务态功能核磁共振，结合基于体素的形态学测量（VBM）技术、弥散张量成像（DTI）技术来阐明异位神经元（舌下神经）修复面神经相关中枢运动网络的可塑性机制；建立面神经损伤及修复过程中，损伤时间-临床症状-电生理改变-大脑皮层重塑之间的相关性模型。.3.重要结果：（1）舌面部运动的共同激活区提示舌面部运动存在共同的激活通路。而与舌上下运动相比，不同的面部运动存在相对的优势激活皮层。（2）与正常对照组相比，在面神经损伤的早期（6个月之内），整合皮层区域（缘上回、楔前叶）激活强度增强。在面神经损伤的晚期（12-24个月），损伤对侧初级感觉运动区激活强度减弱。而在面神经损伤中期（6-12个月），损伤同侧初级感觉运动区激活强度的增强提示半球间功能重塑的可能。（3）舌下神经-面神经吻合术后，患者临床症状改善发生于吻合术后6个月，皮层功能重塑可于吻合术后3个月发生，吻合术后皮层功能重塑有利于术后面神经功能的恢复。（4）吻合术前后面神经损伤对侧初级感觉运动区激活强度与吻合术后面神经临床症状改善相关。.4.关键数据：主要存在于各个术前及术后阶段患者功能磁共振数据对比结果。.5.科学意义：准确定义面神经舌下神经吻合术后患者皮层功能区的改变为日后介入指导患者临床治疗时间及后期外周电刺激及中枢磁刺激康复治疗给予理论指导。