不同程度失神经支配的面神经和面肌超微结构观察

Ultrastructure of Facial Nerve and Facial Muscles with Different Degrees of Denervation

目的：探讨不同程度失神经支配的面神经和面肌的病理变化，为判断预后和制定治疗方案提供参考。方法：制作豚鼠面神经不同损伤程度的面神经麻痹实验模型，应用透射电镜扫描电镜观察面神经和口轮匝肌超微结构变化。结果：压榨面神经５ｓ组只见髓鞘轻度病变，肌纤维无异常改变；３０ｓ组髓鞘和轴突及肌纤维都呈重度病理改变；１５ｓ组神经纤维和肌纤维处于前两组改变的中间状态。结论：面神经失神经支配程度越重，面神经纤维和面肌肌纤维的病理变化越重，轻、中度失神经支配的面瘫是可逆性面神经麻痹，重度失神经支配的颅骨外伤性面瘫，早期行面神经减压术，有利于面神经功能恢复。

Objective: Our aim was to study the pathological changes of facial nerve and facial muscles with different degrees of facial nerve denervation in order to provide reference for judgement of prognosis and strategy of treatment. Methods: 30 guinea pig models of facial nerve paralysis with different degrees of facial nerve injury were made and ultrastructural changes of facial nerve and musculus orbicularis oris were observed by transmission and scanning electron microscope respectively. Results: Mild changes of myelin sheath and no abnormal changes of muscle fibers were demonstrated for the guinea pigs whose facial nerve had been compressed for 5 seconds. Severe pathological changes of myelin sheath, axon and muscle fibers were observed for the guinea pigs whose facial nerve had been compressed for 30 seconds. The changes of nerve fibers and muscle fibers of the 15 second group were between that of 5 second group and that of 30 second group. Conclusion: The severer the degree of facial nerve denervation was, the severer the pathological changes of facial nerve fibers and facial muscle fibers were. Facial nerve paralysis with mild and moderate degree of denervation was reversible. The operation of facial nerve decompression could benefit the recovery of facial nerve function for the models with serious denervation facial paralysis caused by cranial injury.