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

重复经颅磁刺激（rTMS）是一种可以改变人体皮层兴奋性的无创方法。我们已经报道了低频rTMS在对侧初级运动皮层（M1）上改善中风患者受影响手的运动表现。此外，我们研究了双侧rTMS在同侧M1上增加高频rTMS是否可以改善脑卒中患者患手的运动功能。低频rTMS通过减少经胼胝体抑制促进同胼胝体M1的兴奋性，而高频rTMS直接刺激同胼胝体Ml，可能会诱导同胼胝体M1更强的兴奋性。近期我们将分析这些结果的数据，我们将建立新的脑卒中神经康复策略。人们一直认为残存的结构和网络有助于脑卒中患者的运动恢复，然而，脑卒中后重组的机制仍不确定。我们利用经颅磁刺激进行虚拟损伤研究，探讨运动恢复的机制。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，与反应时间延迟和沉默期相比，PMC的抑制功能有所下降。与手部相比，PMC的重组与上臂相对良好的功能呈负相关。关于重组，有报道称，手和上臂区域在皮层内竞争。上臂的兴奋性不均匀分布可能是由于PMC抑制功能弱导致控制手的皮层重组不良。这种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.