STANDARDIZATION OF FACILITATION OF COMPOUND MUSCLE ACTION-POTENTIALS EVOKED BY MAGNETIC STIMULATION OF THE CORTEX - RESULTS IN HEALTHY-VOLUNTEERS AND IN PATIENTS WITH MULTIPLE-SCLEROSIS
STANDARDIZATION OF FACILITATION OF COMPOUND MUSCLE ACTION-POTENTIALS EVOKED BY MAGNETIC STIMULATION OF THE CORTEX - RESULTS IN HEALTHY-VOLUNTEERS AND IN PATIENTS WITH MULTIPLE-SCLEROSIS
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DOI：
10.1016/0168-5597(91)90072-6
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发表时间：
1991-06-01
期刊：
影响因子：
--
通讯作者：
DAHL, K
中科院分区：
文献类型：
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作者：
RAVNBORG, M;BLINKENBERG, M;DAHL, K
为了建立标准化的重要性，通过磁刺激测量中枢运动传导的促进，我们研究了增加随意肌收缩对3个上肢和2个下肢肌肉的中枢运动传导时间（CMCT）和运动诱发电位（MEP）幅度的影响。通过磁刺激皮层和脊神经根诱发MEP，从综合电肌肉活动中间接评估肌肉力量，并表示为均方根（RMS），其变化范围为最大活动的0 - 40%。中枢运动传导时间（CMCT）在增加肌肉收缩期间减少，在约10- 20%RMS（最大值）时达到恒定值。同样，MEP振幅的增加在大约相同的RMS水平上逐渐减少。对于每一块肌肉，最佳RMS水平被定义。CMCT在最佳RMS水平的缩短为：肱二头肌，3.4毫秒;桡腕屈肌，2.7毫秒;手的第一骨间背侧肌，2.9毫秒;胫骨前肌，4.2毫秒;拇展肌，2.4毫秒。标准化程序应用于10例多发性硬化患者。与正常人相比，这些患者的刺激阈值较高。只有BB的CMCT降低显著大于对照组（8.1 msec）。使用标准化易化，振幅的诊断价值似乎仅略低于CMCT的诊断价值。
To establish the importance of standardization of the facilitation of central motor conduction measured by magnetic stimulation we studied the effect of increasing voluntary muscle contraction on the central motor conduction time (CMCT) and motor evoked potential (MEP) amplitudes for 3 upper and 2 lower limb muscles. MEPs were elicited by magnetic stimulation of the cortex and the spinal roots.Muscle force was indirectly assessed from the integrated electrical muscle activity and expressed as the root mean square (RMS) and was varied from 0 to 40% of maximal activity. The central motor conduction time (CMCT) decreased during increasing muscle contraction, reaching constant values at approximately 10-20% RMS(max). Similarly, the increases of MEP amplitude tapered off at about the same RMS level. For each muscle an optimal RMS level was defined.The shortening of the CMCTs at the optimal RMS levels were: the brachial biceps, 3.4 msec; the radial carpal flexor of the wrist, 2.7 msec; the first dorsal interosseus muscle of the hand, 2.9 msec; the anterior tibial, 4.2 msec; and the abductor hallucis, 2.4 msec. The standardizing procedure was applied to 10 patients with multiple sclerosis. The stimulus thresholds were higher in these patients compared with those of the normals. Only the CMCT reduction of the BB was significantly larger (8.1 msec) than in the controls. Using standardized facilitation the diagnostic value of the amplitudes seems to be only a little less than that of the CMCTs.