兔腰骶神经根牵拉的微循环和体感诱发电位变化的研究

目的建立一种不同程度的腰骶神经根牵拉损伤动物模型,探讨脊髓神经根牵拉损伤后微循环和电生理改变。方法将40只中国大白兔随机分为对照组、轻度牵拉组、中度牵拉组和重度牵拉组。全椎板切除显露双侧荐1神经根,用测力神经根拉钩分别以不同的拉力造成神经根的牵拉性损伤。行体感诱发电位监测神经根和骶髓微循环研究。结果轻度牵拉组SEP潜伏期比对照组相稍延长(P>0.05),神经根和骶髓微血管密度轻度增加;中度牵拉组SEP潜伏期明显延长(P<0.05),去除牵拉后潜伏期接近正常(P>0.05),神经根和骶髓微血管密度明显增加;重度牵拉组SEP潜伏期明显延长(P<0.01),去除牵拉后潜伏期稍缩短,和对照组仍存在显著性差异(P<0.05),神经根和骶髓微血管密度轻度增加。结论以拉力为参数可以稳定的建立不同程度的腰骶神经根牵拉性损伤动物模型,微血管密度和SEP可以较好的衡量神经根和脊髓的损伤程度。

A Experimental Study of Microcirculation and Electrophysiology in Rabbit of Tractive Iumbar-sacral Nerve Root Injury

Objective To establish an animal model of graded tractive lumbar-sacral nerve root injury in rabbits,discuss the CSEP and MVD after lumbar-sacral nerve root injury.Methods 40 rabbits were randomly divided into 4 groups: control group without traction,light traction group,middle traction group and serious traction group.The model was induced by dragging the first left sacral nerve root in different degrees of traction with a special retractor after exposing the spinal cord entirely via bilateral laminectomy,then neurophysiologic evaluation was performed and tissue samples were harvested for histological analyses.Results The neural electrophysiological changes and MVD were correlated with traction.The larger the traction,the longer the latency of SEP P1 wave and the more severe of the MVD change.The light traction group showed no significant difference compared with the control group throughout the experimental period. For the middle traction group,the latency of SEP P1 waves were significantly longer than the control nerve roots during the traction,but not significant after the traction.The latency of SEP P1 wave was significantly longer.Conclusion This animal model of tractive lumbar-sacral nerve root injury was based on different degrees of trction.It has stable and repetitive characters for research on basic pathophysiologic mechanisms and on the effects of various interventions on nerve root injury.MVD and CSEP can measure injury degree of spinal cord and nerve root better.