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

前言：为研究兔坐骨神经在双重挤压状态下的易损性，进行了实验研究。材料和方法：成年兔，体重约3200g，为动物模型。暴露右侧坐骨神经，在近端和远端(双卡压组；A组)、仅近端(单卡压组；B组)或远端(单卡压组；C组)放置硅管带。管径近端为2.0 mm，远端为1.5 cm。结果：肉眼可见A组1只兔近端为假神经瘤，远端3只兔中有1只远端可见小的假神经瘤，B组和C组各3只兔各1只可见小的假神经瘤。光镜下，A组3只兔6个卡压区全部脱髓鞘，B、C组3只兔3个卡压区均见脱髓鞘。脱髓鞘程度以A组最明显，A组近端脱髓鞘明显，B组和C组轻度至轻度脱髓鞘。A组3只兔6个卡压区MCV均延迟，B、C组3只兔每只脱髓鞘脱髓鞘程度正常。

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.