目的:研究可靠的脊髓半切动物模型的制作方法和损伤后SEP和MEP的变化。方法:选用30只SD雄性大鼠.随机分成3 组,正常对照组、假手术组和脊髓半切组各10只。脊髓半切在手术显微镜下进行。脊髓半切分3步:定位中线、脊髓横旋切和确认半切。脊髓半切后2 h进行SEP和MEP检查,动物完全清醒后进行患侧后肢运动功能评价。结果:所有动物均成功进行脊髓半切, 脊髓半切侧的下肢完全瘫痪,对侧下肢受影响不明显。动物清醒后能自行排尿,无腹胀、血尿等。完全半切侧检验不到MEP和SEP;而未损伤侧的MEP波幅稍有下降,但与正常对照组和假手术组相比差异无统计学意义;未损伤侧与正常组、假手术组之间的MEP潜伏期以及SEP潜伏期和波幅的差异也无统计学意义。结论:脊髓半切的“三步法”准确而完全,是制作该动物模型简单有效的方法。MEP可能比SEP更敏感和可靠,更适合用于脊髓半切后半切是否完全和准确以及脊髓功能的客观判定指标之一。 OBJECTIVE: To study the preparation of a reliable model of spinal cord hemisection and the changes of SEP and MEP after injury. Methods: Thirty SD male rats were randomly divided into three groups: normal control group, sham operation group and spinal cord hemisection group. Spinal hemispheres under a surgical microscope. Half-cut spinal cord 3 steps: positioning the midline, spinal cord lateral rotation and confirm the half-cut. Spinal cord hemisection 2 h after SEP and MEP examination, the animal fully awake ipsilateral motor function evaluation of hindlimb. Results: All animals were successful in hemisection of the spinal cord. The paraplegic lower limbs in the hemisected side of the spinal cord were completely paralyzed and the contralateral lower limbs were not affected obviously. Animal awake after their own voiding, no bloating, hematuria and so on. MEP and SEP were not detected on the complete hemisection side; while the amplitude of MEP on the uninjured side slightly decreased, but there was no significant difference compared with the normal control group and the sham operation group; between the uninjured side and the normal control group and the sham operation group MEP latency and SEP latency and amplitude differences were not statistically significant. Conclusion: The “three-step method” of hemisection of the spinal cord is accurate and complete, which is a simple and effective method for making the animal model. MEP may be more sensitive and reliable than SEP, and more suitable for semi-incision of the spinal cord is complete and accurate, and one of the objective judgments of spinal cord function.