应用大脑皮质诱发电位建立运动-静止压迫型脊髓损伤模型的实验研究

Establishment of motorial-static-compressed animal models of spinal cord injury by using cortex somatosensory evoked potentials

目的:脊髓损伤的动物模型是当前国内外致力探讨的课题,建立一种不同程度的脊髓损伤精确动物模型有助于为脊髓损伤的恢复带来新的突破。方法:自行设计一种犬的运动-静止压迫型脊髓损伤模型,以大脑皮层诱发电位(cortexSomatosensoryevokedpotentials,CSEP)和不同压迫时间为参数,随机分为:A组:8只,脊髓受压30min;B组:8只,脊髓受压180min;C组4只为对照组,脊髓显露后不损伤。观察电生理学、组织病理学、运动功能恢复、MRI变化。结果:A,B两组脊髓组织学均有损害、MRI显示两组均有脊髓受压性改变,B组脊髓组织损害程度和MRI显示的受压体积显著大于A组(P<0.001);A组CSEP逐渐恢复达基线的76%,B组CSEP无恢复;脊髓受压早期A,B两组均有后肢功能障碍,A组1周后基本恢复后肢功能,B组4周仍无恢复,两组差异有显著性意义(P<0.01)。结论:以CSEP和不同压迫时间为参数,能够建立不同损伤程度的分级脊髓损伤模型。

AIM:The animal model of spinal cord injury(SCI) become a popular topic at home and abroad. The aim of this paper is to establish an accurate animal model of SCI in different degrees of impact so as so benefit rehabilitation of SCI. METHODS: The motorial static compressed dog models of SCI were self designed. With cortex somatosensory evoked potentials(CSEP) and different time of compression as parameters, the models were randomly divided into group A, 8 dogs underwent spinal cord compression for 30 minutes; group B, 8 dogs underwent spinal cord compression for 180 minutes; group C, 4 dogs with spinal cord uninjured after exposure were as control group. Eilectrophysiology, histopathology, recovery of motor function, and change of magnetic resonance imaging(MRI) were observed. RESULTS: The histology of spinal cord in both groups A and B was injured; MRI showed that both groups had changes of spinal cord compression. The injury level of spinal cord tissue and the compressed volum showed by MRI in group B were significantly greater than that in group A (P< 0.001). The CSEP in group A recovered gradually to 76%of the baseline, but there was no recovery of CSEP in group B. Both groups A and B had dysfunctions of hindlimbs in the early phase of spinal cord compression. The function of hindlimb was basically recovered in group A after one week, and there was no recovery in group B after 4 weeks(P< 0.01). CONCLUSION: The animal model of graded SCI in different degrees of impact can be made with two parameters of CSEP and different time of compression.