皮层体感诱发电位监测轻度医源性脊髓冲击损伤的实验研究

目的 研究皮层体感诱发电位(somatosensory evoked potentials,SEP)在大鼠脊髓轻度冲击伤中的变化,评价其在预防此类医源性脊髓损伤中的临床价值.方法 SD大鼠24只,体重(340±28)g,按随机数字表法分为损伤组和对照组,每组12只.损伤组用改良重物坠击法制成C6节段脊髓轻度冲击伤模型,对照组仅行C6节段硬脊膜显露不做冲击.两组实验过程中均实施SEP监测,分别对两组和造模前后的SEP波形、幅值和潜伏期观察比较,并进行病理学研究.结果 对照组SEP波形、幅值和潜伏期未出现显著变化;损伤组SEP在脊髓冲击性损伤后波形和幅值发生显著变化,由损伤前的(1.3±0.7)μV降为(0.5±0.4)μV(P<0.05),而潜伏期差异无统计学意义[损伤前(11.1±2.1)ms:损伤后(10.7±1.3)ms(P>0.05)].该异常变化仅短暂出现在损伤后(5.7±3.2)min,持续(7.1±3.3)min.组织学观察发现,损伤后脊髓内散在灶状出血,而对照组未见组织学异常.结论 脊髓轻度冲击伤可引起SEP短暂异常,术者应密切注意术中SEP变化.术中SEP突然异常可能与手术操作中冲击和震荡所致脊髓损伤有关,应该考虑及时使用预防性脊髓保护措施.

Abstract：

Objective To investigate the changes of somatosensory-evoked potential(SEP)during an mild impact spinal cord injury in rats 80 as to evaluate its potential value in prevention of such iatrogenic damage. Methods Twenty-four SD rats weighing(340±28)g were randomly divided into two groups,ie,sham control group(only exposure without impact at C6)and injury group(mild impact spihal cord injury at C6).SEP wss recorded in both groups.The changes of SEP in waveform,amplitude and latency were observed and compared between groups and between operations.The gross dissection and histologic analysis were performed after surgery for comparative study. Results SEP waveforms,amplitude and latency showed no significant change in the sham control group.In contrast,the SEP waveform and amplitude animals showed significant changes in the injury group after impact spinal cord injury and the amplitude was decreased from pre-injury(1.3±0.7)μV to post-injury(0.5±0.4)μV(P<0.05),while the latency showed no significant difference between(11.1±2.1)ms pre-injury and(10.7±1.3)ms post-injury(P>0.05).However,this abnormal change appeared in a temporary period at(5.7±3.2)minutes after impact and lasted for about(7.1±3.3)minutes.Diffused hemorrhagic nidus could be seen in the injured cord,which was not found in the sham control group. Condusions Mild impact spinal cord injury may induce transient abnormalities of SEP in waveform and amplitude,which requires careful monitoring in clinical practice.The sudden change in SEP may be associated with impact and vibration damage to the spinal cord,suggesting timely use of protection measures for spinal cord.

Monitoring mild impact iatrogenic spinal cord injury by using somatosensory-evoked potential: an experimental study

Objective To investigate the changes of somatosensory-evoked potential(SEP)during an mild impact spinal cord injury in rats 80 as to evaluate its potential value in prevention of such iatrogenic damage. Methods Twenty-four SD rats weighing(340±28)g were randomly divided into two groups,ie,sham control group(only exposure without impact at C6)and injury group(mild impact spihal cord injury at C6).SEP wss recorded in both groups.The changes of SEP in waveform,amplitude and latency were observed and compared between groups and between operations.The gross dissection and histologic analysis were performed after surgery for comparative study. Results SEP waveforms,amplitude and latency showed no significant change in the sham control group.In contrast,the SEP waveform and amplitude animals showed significant changes in the injury group after impact spinal cord injury and the amplitude was decreased from pre-injury(1.3±0.7)μV to post-injury(0.5±0.4)μV(P<0.05),while the latency showed no significant difference between(11.1±2.1)ms pre-injury and(10.7±1.3)ms post-injury(P>0.05).However,this abnormal change appeared in a temporary period at(5.7±3.2)minutes after impact and lasted for about(7.1±3.3)minutes.Diffused hemorrhagic nidus could be seen in the injured cord,which was not found in the sham control group. Condusions Mild impact spinal cord injury may induce transient abnormalities of SEP in waveform and amplitude,which requires careful monitoring in clinical practice.The sudden change in SEP may be associated with impact and vibration damage to the spinal cord,suggesting timely use of protection measures for spinal cord.