AN EXPERIMENTAL STUDY OF THE DOUBLE CRUSH SYNDROME IN SCIATIC NERVE OF RABBIT

前言：对兔坐骨神经在双挤压情况下的易损性进行了实验研究。材料与方法：体重约3200g的成年兔子为动物模型。暴露右侧坐骨神经，在近端和远端区域（双压迫组，A组）放置硅管带，仅近端区域（单压迫组，B组）或远端区域（单压迫组，C组）放置硅管带。根管近端直径2.0 mm，远端直径1.5 cm。6 ~ 12周后，用^3H-Leucin评价形态学结果、运动传导速度（MCV）和快速轴突血流。结果：a组1只家兔在近端压迫区带近端可见小假神经瘤，3只家兔中1只家兔在远端压迫区可见小假神经瘤，B组和C组3只家兔各1只家兔可见小假神经瘤。显微镜下，A组3只兔的6个陷陷区均见脱髓鞘，B组和C组3只兔的3个陷陷区均见脱髓鞘。A组远端脱髓鞘程度最显著，A组近端脱髓鞘程度显著，B组和c组脱髓鞘程度弱至轻度，A组3只兔6个脱髓鞘区MCV均延迟；在A、B、C组中，^3H-Leucin仅在近端卡压区升高，而在A组中，^3H-Leucin在近端和远端卡压区均显著升高。讨论：从形态学和电生理结果以及快速轴突血流评估结果来看，双卡压情况下神经的易损性增加。

Introduction : An experimental study to investigate the vulnerability of the sciatic nerve of rabbit in the double crush situation was performed.Materials and Methods : Adult rabbits, weighing approximately 3200g were animal models. The right sciatic nerve was exposed and bands of silicon tubes were placed on proximal and distal areas(double entrapment group ; group A)and only a proximal area(single proximal entrapment group ; group B) or distal area(single distal entrapment group ; group C). The diameter of the tubes were 2.0 mm in the proximal and 1.5 cm in the distal. After 6 to 12 weeks, evaluations of morphological findings, motor conduction velocity(MCV), and fast axonal flow using ^3H-Leucin were performed.Results : Macroscopically, small pseudoneuroma was seen just proximal to the band of proximal entrapment area in one rabbit and in distal area in one of three rabbits respectively in group A.A small pseudoneuroma was seen only in one each rabbit of three in group B and C respectively. Microscopically, demyelination was seen in all six entrapment areas of three rabbits in group A,and each of three entrapment areas of three rabbits in group B and C respectively. Degree of the demyelination was the most remarkable in distal entrapment area of group A,remarkable in proximal entrapment area of group A and weak to mild in group B and C.While MCV was delayd in all six entrapment areas of 3 rabbits in group A ; it was normal in each one of 3 rabbits in group B and C.Whereas, ^3H-Leucin elevated just proximal to all entrapment areas in group A,B and C,was elevated remarkably in both proximal and distal entrapment area of the rabbits in group A.Discussion : From the results of morphological and electrophysiological findings and evaluation of fast axonal flow, vulnerability of the nerve in a double entrapment situation increased.