磁刺激腰骶部神经根的兴奋点及其在腰骶神经根病中的应用

The magnetic stimulation exciting site of the lumbosacral root and its clinical application in lumbosacral radiculopathy

采用磁刺激腰骶部的神经根运动诱发电位（MEPs）和磁刺激窝F波相结合的方法测定运动神经根传导时间（MRCT）。随机抽查50名正常受试者，在胫前肌（TA）和比目鱼肌（SOL）记录出可靠的运动神经传导时间（MNCT）和MRCT，并根据MRCT推算磁刺激腰骶部神经根的兴奋点位置，结合5例尸解测出的L5和S1神经根的长度，确定该兴奋点在椎间孔的近端。同样方法记录和观察40例手术证实单侧L5或S1神经根受压患者MNCT和MRCT的改变。结果显示：病人组与正常组相比MNCT无显著性差异，而MRCT有显著性差异，异常率为85％。作者认为，无痛无创的磁刺激MEPs对腰骶神经根病有很大的诊断价值。

Motor root conduction time (MRCT) by the magnetic stimulation in lumbosacral region with F wave elicited by same method used in poplitea1 fossa was calculated. Motor nerve conduction time (MNCT) and MRCT were accurately recorded from the tibialis and soleus.The site of excitation after magnetic stimulation over lumbosacral verterbral column could be deduced according to MRCT. Com-parotive study of the lengths of L, and S, roots in 5 cadavers,the exciting site was considered in the in-terverterebral foramen before the exits of the roots. MNCT and MRCT were calculated in 40 patients suffering from L5 or S1 radiculopathy owing to disc protrution. The results showed that no difference was seen in MNCT in all patients but MRCT was markebly prolonged in 85% of the patients. It is conclud-ed that magnetic stimulation of MEPs is an useful technique for non-invasive diagnosis of lumbosacral.radiculopathies.