甲基强的松龙对脊髓损伤后脊髓病理生理变化的影响

目的探讨脊髓受压及减压后,甲基强的松龙对脊髓灰质血流量,体感诱发电位（SEP）,组织学变化,运动功能的影响。方法 36只犬随机分为2组,每组18只。实验组：甲基强的松龙（30mg/kg）以5.4mg/（kg.h）用静脉泵静脉注射。对照组应用0.9%氯化钠注射液以同样方式静脉注射。两组注射时间均为SEP消失后5min。均持续90min后减压,期间检测SEP及脊髓灰质血流量,减压后3h重复检测,并进行改良Tarlov评分。减压后28d通过病理组织学分析确定损伤范围。结果在持续压迫期间实验组7只犬出现了SEP,对照组无一出现。减压后实验组对照组均有3只犬出现SEP。两组犬中出现SEP的脊髓灰质血流量明显高于没有出现SEP的（P〈0.05）。实验组犬的脊髓灰质血流量在减压后5min恢复到基线水平,对照组始终未恢复到基线水平。实验组脊髓灰质血流量明显高于对照组（P〈0.05）。实验组动物后肢的运动功能可较快恢复,对照组不能恢复。实验组脊髓损伤范围与对照组具有显著性差异,病理改变与SEP及脊髓血流量具有相关性,与运动功能的恢复具有相关性。结论甲基强的松龙在神经功能保护及恢复方面提供了显著持续的作用,可能增加了脊髓局部的血流量。

Effect of methylprednisolone on pathophysiological changes after spinal cord injury

Objective To study the effect of methylprednisolone on regional spinal cord blood flow,electrophysiological function,histopathological changes and motor functional recovery.Methods Thirty-six canines were randomly divided into experimental group（n=18） and control group（n=18）.Canines in experimental group received intravenous injection with methylprednisolone（30mg/kg）,5.4mg/kg each hour,while those in control group received intravenous injection with 0.9% sodium chloride 5min after SEP was disappeared.SEP and blood flow in spinal cord were measured during the 90min sustained compression,which was repeated 3h after decompression and scored.Lesion size was measured by histological analysis 28 days after decompression.Results SEP occurred in 7 canines of experimental group during decompression.However,no SEP was found in control group.SEP occurred in 3 canines of both groups after decompression.The blood flow volume in spinal cord was greater in canines with SEP than in those without SEP（P〈0.05）,returned to its basal level in experimental group 5min after decompression,and was significantly greater than that in control group（P〈0.05）.The motor function of hind limbs was rather rapidly recovered in experimental group but not in control group.The lesion size of spinal cord was significantly different between the two groups.The pathological change was correlated with SEP,blood flow in spinal cord,and recovery of motor function.Conclusion Methylprednisolone can significantly protect and restore the function of nerves and increase the regional blood flow in spinal cord.