面肌失神经支配后线粒体变化与功能康复的关系

目的:探讨不同程度面神经失神经支配后口轮匝肌线粒体结构、琥珀酸脱氢酶(SDH)的变化与面肌功能恢复的关系。方法:制造颞骨内面神经麻痹模型,分为面神经压榨5s组(11例)、15s组(10例)、30s组(10例),应用神经电图测试3组的平均阈值差值,SDH染色后,透射电镜观察面神经损伤15,30d后口轮匝肌线粒体结构和SDH阳性反应产物的变化。结果:压榨持续时间越长,反应阈值差值越大,5s组、15s组、30s组的反应阈值差值分别为0.443±0.024,12.174±1.532,15.720±1.536,组间比较差异有显著性意义(F=461.560,P<0.0001)。面神经压榨5s组的平均神经兴奋传导抑制时间为(35±17)min;15s组瞬目反射恢复正常需(47±15)d;30s组半年内未恢复。15s组面神经损伤15d后,线粒体嵴断裂,SDH阳性反应颗粒减少,损伤30d基本恢复正常。30s组面神经损伤15d后,线粒体空泡变性,SDH颗粒明显减少,损伤30d后的线粒体结构和SDH颗粒有轻度恢复。结论:面神经受损伤时间越长,失神经支配程度越重,线粒体病变也越重,面肌功能恢复越难,应早期行面神经减压术。

Relationship between function recovery and the changes of mitochondria after facial muscles denervation

AIM:To explore the relationship between the functional recovery of facial muscles and the changes of the structure of mitochondria and succinate dehydrogenase (SDH) of oris muscles after different degree of denervation. METHODS:Models of facial paralysis were obtained, all 72 guinea pigs were divided into 5 s-pinching group,15 s-pinching group and 30 s-pinching group respectively.Eletroneurogram (ENoG) was used to measure the average threshold differences of the facial nerves of the guinea pigs in each group.The mitochondria structures of oris muscle and positive products of SDH were observed with transmitting electron microscope after facial nerve injuries for 15,30 s respectively. RESULTS:The longer of pinching, the more of threshold difference, 5 s-pinching group (11),15 s-pinching group (10),30 s-pinching group (10). Difference of threshold values of each group was 0.443± 0.024, 12.174± 1.532, 15.720± 1.536, there was a significant difference between groups (F=461.560, P< 0.000 1).The average inhibitory time of nerve excitement conduction was (35± 17) min after pinching the facial nerve for 5 s. Recovery of blink reflex took the guinea pigs in 15 s-pinching group an average of(47± 15) days,and it failed to occur within 6 months in the 30 s group.Electron microscopic studies revealed broken mitochondria crista and decreased positive reaction granules of SDH in guinea pigs of 15 s-pinching group after 15 days,which recovered basically after 30 days.Bubble degeneration and decreased SDH granules could be found in guinea pigs of 30 s-pinching group after 15 days, and were slightly recovered 30 days later. CONCLUSION:The longer time the facial nerve is injured and the more serious the degree of denervation was sustained, the changes of the mitochondria including that of SDH would be more serious and more difficult to recover, so the facial nerve injury should be managed as early as possible.