兔坐骨神经挤压伤的体感诱发电位与病理相关性

目的:探讨体感诱发电位(sensory evoked potential,SEP)在外周神经急性挤压伤中的诊断价值及与肢体功能、病理学改变的关系.方法:24只兔按钳夹力的不同随机分为A、B两组,左下肢为损伤侧,右下肢为对照侧,建立坐骨神经急性挤压伤模型,于伤后1、2、4、8周行双侧体感诱发电位检查,同时观察肢体活动功能及展趾功能,后取材进行病理学检查,结果:SEP诊断外周神经损伤的诊断正确率91.6%,假阳性率为12.50%(3/24);假阴性率为8.3%(2/24).损伤侧的P1N1(波幅)明显低于对照侧(P＜0.01),损伤侧的P1、N1(潜伏期)与对照侧比较无明显统计学差异(P＞0.05).神经损伤1～2周时神经远段轴突肿胀,消失,髓鞘大部分崩解,4～8周髓鞘崩解物质部分吸收,雪旺细胞明显增生,肢体功能逐步恢复,而不同时间组SEP无差异(P≥0.05).结论:SEP对外周神经损伤有一定诊断价值,尚不能动态的、准确的判断神经损伤后神经再生及肢体功能修复的情况.

SEP Correlation with Pathology in Sciatic Nerve Crush Injuries in Rabbits

Objective:To evaluate the diagnostic value of sensory evoked potential(SEP) in crushed rabbit sciatic nerve,and its correlation with pathology and function of posterior limbs.Methods: Models of acute crush injury to the left sciatic nerve were established in 24 adult rabbits,with the right side as controls,and were divided randomly into one of two groups(A and B) based on the pressure of clamping.SEP was measured after crush injury at weeks 1,2,4 and 8 respectively.Function and pathology of the posterior limbs were observed and compared.Results: the rate of correct diagnosis by SEP was 91.6%,along with a false positive rate of 12.5% and false negative rate of 8.3%.There was significantly difference in the amplitude of SEP between the crushed nerves and controls(P<0.01).However,no statistical difference was found in the SEP latency(P>0.05).At weeks 1 through 2,the crushed nerves showed swollen,diminishing axons and myelinolysis;at weeks 4 through 8,as the myelolytic products were absorbed,Schwann cell proliferation was observed,leading to a gradual recovery of the posterior limb functions.There was no statistical difference in incubation period and wave amplitude of individual observational time and crush severity(P>0.05).Conclusions: SEP may be valuable in diagnosing the crushed sciatic nerve in rabbits,but failed to indicate dynamic changes of nerve fiber regeneration and posterior limb function.