磁刺激运动诱发肌电位对运动机能评价的临床应用

目的：观察磁刺激运动诱发肌电位对运动机能的评价。方法：用磁刺激装置对正常人１２例，运动障碍患者３１例进行了经颅脑刺激，记录运动诱发肌电位。结果：受检测的４３例，无一例引起头痛和感觉异常，也无癫痫及意识障碍等副作用。正常人中，诱发肌电位的潜伏期相对恒定，振幅在个体间虽存有差异，但同一例左右侧几乎相同。对２０例单侧肢体功能障碍的肌力按体征分级，比较患侧和健侧的诱发肌电位，发现患侧振幅较健侧明显减低。对肌力０～２级的病例，不能诱发出肌电位。结论：磁刺激运动诱发肌电位，在临床上可在数量上正确评价肢体的运动机能，并且经颅磁刺激法是安全的。

Clinical application of transcranial magnetic stimulation.

Objective: To oberserve the evaluation of motor function with corticomyographic motor evoked potentials (MEPs) by transcranial magnetic stimulation. Methods: The clinical value of magnetic stimulation was investigated in 43 cases, including 12 normal cases and 31 cases with motor disturbance. The MEPs were recorded from the thenar and the extensor carpi radialis muscles with a pair of surface electrodes in response to transcranial magnetic stimulation. Recordings were performed when the subjects were at rest, and also during weak voluntary contraction. Results: The MEPs recorded from the contralateral side to the stimulation revealed an almost constant onset latency. However, the amplitude of the MEPs differed among individual cases of normal motor function, but was almost the same on both sides in the same case. Twenty cases of unilateral motor disturbance were classified according to their MMT gradings, and MEP recorded from the paretic side were compared with those from the intact side. A decreased amplitude of the MEPs recorded from the paretic side was always found. However, a prolonged latency of the MEP was not always seen. Changes in the MEP amplitude thus appeared to represent a good indication of motor function. Conclusion: None of the 43 cases receiving magnetic stimulation complained of side effects, and the magnetic transcranial stimulation method was thus concluded to be useful and applicable for clinical practice.