脊髓减压对脊髓损伤后大鼠体感诱发电位的影响

Changes of somatosensory evoked potentials in spinal cord injury and the influence of the timing of decompression on the recovery of spinal cord function and evoked potentials

目的探讨脊髓损伤大鼠体感诱发电位的变化规律及不同时间解除脊髓压迫对脊髓恢复和诱发电位的影响。方法选择SD大鼠70只,分为对照组(10只)和实验组(60只),实验组分为轻度损伤组(20只)、中度损伤组(20只)、重度损伤组(20只)。采用自行制作的脊髓打击装置建立大鼠脊髓损伤模型。测定大鼠在损伤前、伤后5 min、1 h、6 h、3 d、7 d的体感诱发电位。行减压治疗的模型大鼠,测定其减压前、减压后5 min、1 h、6 h、3 d、7 d的诱发电位。结果脊髓受到的打击程度越重,其潜伏期的延长越显著,波幅的降低越明显(P<0.05)。脊髓损伤后5 min,轻、中、重度损伤组的潜伏期和波幅均较损伤前的波幅变化显著。在解除脊髓损伤压迫前,脊髓受压时间越长,其潜伏期的延长越显著,波幅的降低越明显。解除脊髓损伤压迫后,压迫解除越快的大鼠,体感诱发电位潜伏期的恢复速度越快(P<0.05)。压迫30 min的大鼠在解除压迫7 d后,潜伏期仍较其它各组延长。解除脊髓损伤压迫后,压迫解除越快的大鼠,其体感诱发电位波幅的恢复速度越快(P<0.05)。压迫30 min的大鼠在解除压迫7 d后,波幅仍较其它各组降低。结论脊髓损伤后受压时间越长,其体感诱发电位潜伏期及波幅改变越显著;脊髓损伤后体感诱发电位波幅变化的敏感性优于其潜伏期。

Objective To explore the changes in somatosensory evoked potential(SEP)in rats with spinal cord injury(SCI)and the effects of relieving spinal cord compression at different times on recovery and the evoked potential.Methods Seventy Sprague-Dawley rats were randomly divided into a control group of 10 and an experimental group of 60.The experimental group was further divided into a mild injury group of 10,a moderate injury group of 40 and a severe injury group of 10.Spinal cord injuries with different severities were established in the experimental group using a self-made percussion device.The rats′SEPs were measured before the injury,and 5 minutes,1 hour,6 hours,3 days and 7 days afterward.Some of the rats receiving decompression treatment.Results The more seriously the spinal cord was injured,the longer was the latency and the smaller was the amplitude.Both differences were statistically significant.Rats with longer compression time had significantly longer incubation periods and greater decreases in the amplitude.After relieving the compression,rats from whom it had been relieved earlier had quicker amplitude recovery.For rats under compression for 30 minutes,their amplitude was the lowest seven days later.Conclusions For spinal cord injury,longer compression time can lead to more significant changes in the latency and amplitude of SEP,with the change in the amplitude more significant than that in the latency.