Bilateral repetitive transcranial magnetic stimulation to motor impairment in stroke patients.

重复经颅磁刺激（rTMS）是一种非侵入性的方法，可以改变人类大脑皮层的兴奋性。我们已经报道，低频rTMS的对侧病变的初级运动皮层（M1）改善运动性能的中风患者患手。此外，我们研究了是否双边rTMS加高频rTMS的同侧M1可能会改善中风患者患手的运动功能。低频rTMS通过减少跨胼胝体抑制而促进同侧M1的兴奋性，高频rTMS直接刺激同侧M1，可能是引起同侧M1兴奋性增强的原因。近年来，我们对这些结果进行分析，以期建立新的脑卒中神经康复策略，认为脑卒中后存活的结构和网络有助于脑卒中患者的运动恢复，但脑卒中后的重组机制尚不清楚。本研究采用经颅磁刺激进行虚拟损伤研究，探讨运动功能恢复的机制。运动功能差的患者似乎使用同侧运动前皮质（PMC）来移动麻痹侧。我们发现，与反应时延迟和沉默期相比，PMC的抑制功能降低。PMC的这种重组与上臂相对较好的功能（与手相比）呈负相关。关于重组，据报道，手和上臂区域竞争皮层内的区域。由于PMC的抑制功能较弱，上臂的兴奋性分布不均匀，可能导致控制手的皮层重组不良。这种同病灶M1之外的大规模重组是一个漫长的过程，永远不会导致完全恢复。

Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive method that can change the excitability of the human cortex. We have reported that low-frequency rTMS over the contralesional primary motor cortex (M1) improved motor performance of the affected hand in stroke patients. Moreover, we investigated whether bilateral rTMS adding high frequency rTMS over the ipsilesional M1 might improve the motor function of the affected hand in stroke patients. The stronger excitability of ipsilesional M1 might be induced by low frequency rTMS that facilitate the excitability of the ipsilesional M1 by reducing the transcallosal inhibition and high frequency rTMS that directly stimulate the ipsilesional Ml. In recent we analyze the data from these results, we will establish new neurorehabilitative strategies for stroke.It has been considered that the surviving structures and networks would contribute the motor recovery in stroke patients, however, the mechanism of reorganization after stroke remains uncertain. We have conducted the virtual lesion study using TMS to investigate the mechanism of motor recovery. It appears that patients with poor motor function used the ipsilesional premotor cortex (PMC) to move the paretic side. We found that, compared with the reaction time delays and silent period, the inhibition function decreased in the PMC. This reorganization of the PMC showed a negative correlation with relatively good function of the upper arm when compared with that of the hand. Regarding reorganization, it has been reported that hand and upper arm regions compete of areas within the cortex. The excitability that is unevenly distributed in the upper arm due to weak inhibitory function of the PMC might cause poor reorganization of the cortex that controls the hand. This large-scale reorganization outside the ipsilesional M1 is a lengthy process that never results in complete recovery.