脊髓纵向压缩过程中脊髓诱发电位、血流量和微循环变化

Alterations of MEP and SEP, spinal cord blood-flow and mierocirculation in the experimental spinal cord injury by longitudinal compression

根据临床上脊往后凸畸形矫正过程中，脊柱截骨缩短后的脊髓受力情况，采用脊柱立体定位仪来调节脊髓的压缩量，设计了大鼠脊髓纵向压缩动物模型，模拟脊往后凸畸形矫正的病理变化．使用末梢循环血流仪（氢清除法）、奥林巴氏生物显微镜及显示系统、 ＳＥＮ３２０１刺激器、 ＡＰＰＬＥⅡ机诱发电位检测系统（硬膜外记录），分别观测了脊髓压缩部位及邻近节段不同压缩量脊髓灰白质血流量、动态微循环、运动诱发电位（ＭＥＰ）、感觉诱发电位（ＳＥＰ），并常规光镜检查．结果表明；大鼠脊髓不可逆性压缩的临界值为６．０ｍｍ，脊髓回缩率为１／２６— ｌ／２３；脊髓监护时ＭＥＰ较ＳＥＰ更敏感地反映脊髓功能，是较理想的监护手段；脊髓压缩过程中主要为瘀血性缺血改变，与目前脊髓牵拉压迫过程中报道的变化有所不同。

A new model of experimental spinal cord injury produced by slow graded longitudinal compression in 40 rats was designed by means of kyphosis corrective opera t ion. The exent of cord compression was evaluated by monitoring somatosensory evoked potentials (SEP), motor evoked potentials(MEP), spinal cord blood flow(SCBF), microcirculation and histopathology. The results suggested that the critical irreversable compressed distance of the spinal cord injury was 6mm and its ratio to the spinal length is l/26-l/23. It was also found that both MEP and S,EP. were feasible for the intraoperativs monitoring of spinal cord function, while MEP was more sensitive than SEP.