脊髓急性牵拉损伤动物模型机理研究

目的对犬脊髓(神经根)急性牵拉损伤的病理机制进行初步探讨。方法12只健康成年杂种犬，随机分为对照组和不同程度牵拉损伤组。前后路联合手术离断脊柱后施加纵向牵拉损伤，对牵拉应变率、体感诱发电位(SEP)、神经源性脊髓运动诱发电位(NMEP)、硬膜下压力(SP)、硬膜血流量(EBF)等进行持续观察。伤后取脊髓及神经根标本进行HE、髓鞘神经中丝(NF)及胶原纤维酸性蛋白(GFAP)抗体免疫组织化学染色及电镜超微结构观察。结果牵拉损伤涉及牵拉节段和其上下脊髓及神经根的损伤。牵拉后出现硬膜下压力的显著增高和硬膜血流的显著降低。SEP异常的出现较NMEP更早。结论牵拉后脊髓内压力的增加导致脊髓血流减少。以及直接的机械性牵拉损伤可能是脊髓牵拉损伤的重要机制。

The study on pathological mechanism of canine spinal cord acute distraction injury

Objective To study the pathological mechanism of spinal cord and nerve roots injury during spinal cord acute distraction injury. Methods 12 healthy grown-up hybrid canines were divided into one control group and three graded injury groups at random. One level of lumbar spine was completely separated through combined anterior and posterior approach. Traction injury of the spinal cord was accomplished with Caspar cervical traction device. The strain, somatosensory evoked potentials (SEP), neurogenic motor-evoked potentials (NMEP), subdural pressure (SP), epidural blood flow (EBF) and histology change of the spinal cord and nerve roots were observed continuously. Results The injury of neurological system during spinal cord acute distraction involved spinal cord and nerve roots distracted and the nearby. Obvious increase of EP and obvious decrease of EBF occurred. The impairment of SEP appeared earlier than that of NMEP. Conclusion Decrease of spinal cord blood flow (SCBF) induced by the increase of cord interstitial pressure (CIP), and direct mechanical distraction injury, may be the main pathological mechanism of spinal cord distraction injury.