磁刺激运动诱发电位量化慢性神经根损伤程度的实验研究

目的 研究神经根在慢性嵌压性损伤中，不同损伤程度的神经病理组织学改变与运动诱发电位(MEP)表现形式之间的对应关系。方法 建立神经根慢性嵌压伤的病理模型，用表面磁刺激MEP对损伤神经做动态观察，结合不同损伤程度的神经病理组织学改变情况，研究两者间的相关性。结果 神经的病理形态学改变在有髓神经首先出现髓鞘的变性。此时的MEP表现为潜伏期延长和波形离散。继而脱髓鞘的神经轴突发生变性、断裂及远侧的瓦勒氏变性。MEP则表现为在潜伏期延长的同时伴有波幅降低，且MEP在不同程度的神经病理损伤中具有相应的特征性表现形式。结论 磁刺激MEP的检查指标与神经根慢性嵌压性损伤的程度具有相关性，其表现形式可作为判断神经病理损伤程度的量化指标。

Application of MEP induced by magnetic stimulation in the evaluation of severity of compressive nerve root injury in cat

Objective To explore the relationship between pathological changes and motor evoked potential(MEP) in cat with chronic cervical nerve rootcompression. Methods The pathological models of chronic cervical nerve roots compression under was established, longitudinal observations of the changes of MEP evoked by magnetic stimulation (MS) and pathological manifestations of the nerve roots were conducted, and correlation between MEP and pathological changes was tested. Results The degeneration of myelin sheath was the initial pathological change of the myelinated fibers, which was corresponding to the latency prolongation and increased duration of MEP. Then the nerve root underwent axons degeneration, disruption, and distal Wallerian degeneration while the MEP manifested the prolonged latency and the decreased amplitude. Conclusion There was significant correlation between the MEP and the pathological changes of the nerve roots under chronic compression, indicating that MEP could be used to quantitate the severity of the nerve root compression.