The basic wave pattern of lumbar root potentials and clinical application

我们常规使用形态学检查来客观诊断，辅助临床检查腰根性神经根病。然而，我们并不罕见地遇到临床检查诊断的水平与脊髓造影术结果不一致的情况。在这些情况下，需要进行电生理检查。人们希望设计更直接的电生理检查，使我们能够记录神经系统的电活动，揭示神经传导的实际状态。这种检查的要求如下：1)易于在门诊进行，2)执行风险最小，3)选择性记录传入和传出神经传导，如果可能的话。调查对象是15名腰椎间盘突出症和椎管狭窄患者，以及5名神经学正常的成年志愿者。用表面电极刺激胫神经或腓神经，腰椎…在硬膜外间隙L5/S1、L4/5和L3/4记录到更多的t电位。同时用SRP监测诱发的肌电反应。刺激胫神经在硬膜外电极上记录到两种不同潜伏期的电位，其强度在比目鱼肌中既能诱发H反应又能诱发M反应。研究SRP波幅与相应的H反射和M反应的关系。根据这些结果，在M阈值的阈值刺激将使我们能够监测后根的传导，而M反应的超最大刺激可以起到对前根的作用。在LDH和LSS的后部和前部，1)定位，2)多相波，3)病理性低波幅。15例受检者中11例后根或前根呈阳性和/或多相电位。其余4例均未见病理波形。但4例中有3例采用定量低波幅估计法显示病理性低波幅。尽管仍然存在一些问题，但我们对目前的检查感到满意。较少

We routinely use the morphological examination for an objective deagnosis assisting clinical examinations in lumbar root radicuropathy. We,however, not infrequently encounter the clinical cases in which the level diagnosed by clinical examination does not coincide the result of myelography. In these cases electrophysiological examination are needed. It is desirable to devise more direct electrophysiological examinations which allow us to record electrical activities of the nervous system revealing the actual state of nerve conduction. Requirements for such examination would be as follows; 1) easy applicability in the out-patient clinic, 2) minimal risk on execution, and 3) selective recording of the afferent and efferent nerve volleys, if possible.The investigation was carried out on 15 patients with the lumbar disc herniationand the spinal stenosis, and also five neurologically normal adult volunteers. Tibial or peroneal nerve was stimulated with the surface electrodes, and lumbar roo … More t potential was recorded in the epidural space L5/S1,L4/5 and L3/4. Evoked EMG responses were monitored simultaneously with SRP.Two kinds of potentials with aifferent latencies were recorded from the epidural electrodes by stimulation of the tibial nerve with the intensity evoking both H and M responses in the soleus muscle. The relationship of the amplitude between SRP and the corresponding H-reflex and M-response was examined. From these result the liminal stimulation at the M-threshold would allow us to monitor the conduction of the posterior root and the supra maximal stimulation of the M-response do that in anterior root.In posterior and anterior of LDH and LSS, 1)positivisation, 2)polyphasic wave and 3)pathological low amplitude were examined. 11 cases of the examined 15 cases had the positivisation and/or polyphasic potentials in the posterior or anterior root. The pathological waves were not observed in the remaining 4 cases. But 3 of those 4 cases showed the pathological low amplitude by using the quantitative method for estimating the low amplitude. We found the present examination satisfactory despite some problems still remained. Less