The Effect of Physical Exercise for Hemiparetic Stroke Patients Assessed by EEG and Motor Evoked Potential

本研究的目的是通过对脑电、经皮质磁刺激诱发的运动诱发电位(MEP)和身体平衡的检测，探讨步态训练等体育锻炼对脑卒中偏瘫患者中枢神经系统的影响。研究对象为9例卒中后3个月内在东北大学医院住院接受康复治疗的偏瘫患者。每名受试者在步行10m前、步行中和步行10m后进行脑电检查。分别于治疗前和治疗后1个月进行MEP和身体平衡检查。计算相对功率值(靶区功率与总功率之比)，分析各半球的脑电。行走过程中，双侧大脑半球α频段的相对功率值显著降低，尤以前中央区最为明显。行走时双侧大脑半球中央前部的阿尔法衰减提示，与自主运动相关的皮质活动普遍增强，如Mu节律的抑制。步行时损伤侧大脑半球和步行后非损伤侧大脑半球的β活性增加。这些结果提示，中风患者步行后仍有激活脑功能的作用。物理治疗前后MEP无明显变化。这表明体育锻炼对运动皮质的激活没有特定的作用。作为身体平衡参数的压力中心在物理治疗1个月后有所改善，但对偏瘫患者的小腿进行一次电刺激后也有改善。因此，体育锻炼对中枢神经系统的作用类似于电刺激等物理因素，并被认为是对大脑功能的普遍增强。

The purpose of this study is to investigate the effect of physical exercise like gait training to the central nervous system of hemiparetic stroke patients through examining EEG, motor evoked potential (MEP) induced by transcortical magnetic stimulation and body balance. The subjects were 9 hemiparetic stroke patients who admitted to Tohoku University Hospital for rehabilitation within 3 months after a stroke onset. EEG was examined before, during and after walking in 10 m distance with maximum effort in each subject. MEP and body balance were measured before and 1 month after physical therapy. The value of relative power (ratio of the power in target band to total power) was calculated to analyze EEG in each hemisphere. During walking, there was significant decrease of the values of relative power in alpha band in the both hemispheres especially in the front-central area. Alpha attenuation in the front-central area of the both hemispheres during walking suggested general augmentation of the cortical activity associated with voluntary movement like the inhibition of mu rhythm. The beta activity increased in the injured hemisphere during walking and in the non-injured hemisphere after walking. These results suggested that walking had the effect of activating the brain function even after walk in the stroke patients. MEP did not change between before and after physical therapy. It showed physical exercise had no specific effect to activate the motor cortex. Center of pressure as a parameter of body balance was improved 1 month after physical therapy but it was also improved by one shot application of the electrical stimulation to the paretic lower limb. Therefore the effect of physical exercise for the central nervous system is similar to it of physical agent like electrical stimulation and it is supposed that such effect is general augmentation of the brain function.