实验性家兔脊髓损伤后后肢运动功能与肌肉运动诱发电位的关系

Relationship between muscle motor evoked potentials and hindlimbs motor function in rabbits with spinal cord injury

目的了解实验性家兔脊髓损伤模型损伤后肢体肌力和肌肉运动诱发电位(MEP)之间的关系。方法 45只家兔随机分为打击组和对照组共9组,打击能量分别为0、50、75、100、125、150、175、200、250gcf。打击后和第4周末记录实验兔双后肢肌力、MEP的潜伏期和波幅,并在第4周末取家兔脊髓固定,脊髓神经中丝(NF)免疫组化及病理形态观察,测量NF光密度,进行统计分析。结果脊髓受到外伤打击后,术中MEP的表现是出现或消失,即"有或无",并与伤后实验兔后肢运动功能状态、术后皮质脊髓束神经微丝NF光密度相关。伤后4周实验兔的后肢MEP潜伏期延长程度与肌力下降呈线性相关,但其波幅与伤后肌力变化无相关。结论在脊髓损伤中可以通过肌肉MEP的"有或无"作为判断脊髓损伤程度的指标。

Objective To study the relationship between muscle motor evoked potentials （MEP） and hindlimbs motor function in rabbits with spinal cord injury. Methods Forty-five rabbits were randomly divided into 9 groups, including one control group and 8 injured groups （receiving Allen＇s injury of 0, 50, 75, 100, 125, 150, 175, 200, or 250 get）. Hindlimb strength and muscle MEP were recorded at the 1st day and 4th week postoperatively. At 4 weeks after spinal section, the spinal cord tissue was sampled for histological examination with HE staining and immunohistochemistry with anti-NF antibody of the corticospinal tract fibers. Results During the operation, MEP showed an all-or-none pattern with significant correlations to postoperative optical density of NF and postoperative hindlimb motor function. The latency prolongation of the muscle MEP at the 4th week showed a linear correlation to the hindlimb Tarlov＇s score, whereas the MEP amplitude was not correlated to postoperative hindlimb motor function. Conclusion The all-or-none pattern of muscle MEP can be used to evaluate the severity of spinal cord injury.