运动诱发电位和BBB评分在大鼠脊髓损伤功能评价中的相关性研究

目的 探讨大鼠脊髓损伤功能评价指标运动诱发电位(MEP)和Basso-Beattie-Bresnahan (BBB)评分的相关性。方法 成年雌性SD大鼠16只,采用数字表法随机分为对照组和实验组,每组8只。对照组只施行手术,不给予外力打击。实验组应用PSI-IH装置复制脊髓损伤模型。记录并分析损伤前以及损伤后3 h、1 d、3 d、1周、2周、3周、4周、5周、6周大鼠脊髓运动诱发电位(scMEP)和肌肉运动诱发电位(mMEP),同时采用BBB评分对大鼠后肢运动功能进行评定。6周后观察大鼠脊髓组织学结构变化。结果 实验组大鼠脊髓损伤后3 h scMEP波幅减小,为正常波幅的32.69%±0.83%,2周后为正常波幅的52.93%±2.23%并处于稳定状态,但均低于对照组(P值均＜0.01);损伤后3 h mMEP波形消失,1 d后恢复至正常波幅的1.16%±0.17%,3 d后波幅明显恢复,4周后达正常波幅的48.20%± 3.70%并处于稳定状态,但均低于对照组(P值均＜0.01)。实验组大鼠脊髓损伤后3 h和1 d,所有大鼠BBB评分均为0分,3 d后评分(1.38±0.52)分,4周后评分(11.50±0.93)分,达到稳定状态,但均低于对照组(P值均＜0.01)。实验组大鼠脊髓损伤后3 h~6周,scMEP与BBB评分均为显著相关(r值为0.732~0.908,P值均＜0.05)。实验组大鼠脊髓损伤后1~6周mMEP与BBB评分呈中度至高度相关(r值为0.718～0.951,P值均＜0.05)。对照组大鼠以上各指标均无显著变化。结论 大鼠脊髓损伤发生后,scMEP、mMEP和BBB评分三个脊髓功能指标会先后顺序恢复,而且scMEP、mMEP与BBB评分均存在着一定的相关性。大鼠脊髓损伤后,scMEP、mMEP是较BBB评分更为灵敏的脊髓功能评价指标。

The correlation between motor evoked potential and BBB score of spinal cord injury in rats

Objective To investigate the correlation between motor evoked potential (MEP) and Basso-Beattie-Bresnahan (BBB) scores in evaluating spinal cord injury function in rats.Methods Sixteen adult female SD rats were randomly divided into control group and experimental group with 8 rats in each group. The animals of control group were only operated without external force, and the animals of experimental group were made the spinal cord injury (SCI) model used PSI-IH device. The spinal cord motor evoked potential (scMEP) and muscle motor evoked potential (mMEP) were recorded and analyzed before injury and 3 h, 1 d, 3 d, and the 1st, 2nd, 3rd, 4th, 5th, 6th weeks after injury. The motor function of hind limbs was evaluated by BBB score. The histological changes of spinal cord were observed 6 weeks after SCI.Results After SCI, the amplitude of scMEP in the experimental group decreased to 32.69%±0.83% of the normal amplitude at 3 hours, and it reached 52.93%±2.23% of the normal amplitude at 2 weeks later, which was stable, but was lower than that of control group (all P values＜0.01); the mMEP waveform disappeared at 3 hours after SCI, and it reached to 1.16%±0.17% of the normal amplitude after one day of injury. 4th week after SCI, the amplitude of mMEP was 48.20%±3.70% of normal amplitude and was stable, but it was lower than that of the control group (all P values＜0.01). The BBB score in the experimental group were 0 at 3 hours and 1 day after SCI. The BBB scores were 1.38±0.52 after 3 days and which were 11.50±0.93 after 4 weeks, reaching a stable state, but they were lower than those of the control group (all P values＜0.01). In the experimental group, there was a significant correlation between scMEP and BBB score (r 0.732-0.908, all P values＜0.05) from 3 h to 6th week after SCI. There was a moderate or high correlation between mMEP and BBB score in the experimental group from 1st to 6th week after SCI (r 0.718-0.951, all P values＜0.05). There were no significant changes in the above indexes of the control group.Conclusions After SCI in rats, scMEP, mMEP and BBB scores will be recovered sequentially, and are correlated to some extent. In addition, scMEP and mMEP are more sensitive indicators of SCI than BBB scores.