rTMS联合运动训练对静息态脑网络影响的研究

The Effects of rTMS Combined with Motor Training on Brain Network in Resting Status

重复经颅磁刺激(r TMS)联合运动训练可以提高肢体运动能力,在脑卒中后的运动康复中有重要的应用价值。探讨r TMS联合运动训练对静息态脑网络的影响。招募10名健康受试者,使用1 Hz r TMS刺激优势半球,结束后非利手立即执行运动训练,以提高非利手的运动能力,r TMS联合运动训练共持续14天。采集r TMS联合运动训练前后闭目静息态的脑电(EEG)信号,使用相位延迟指数(PLI)进行功能连接性分析,并以PLI值为边的权重计算依据来建立有权无向脑网络,计算网络节点的最短路径长度和节点效率,使用非参数符号秩和检验进行统计学分析。结果发现,r TMS联合运动训练使EEG低频段(theta和alpha)脑功能区间的连接显著增加、高频段(beta、gamma1和gamma2)显著降低,对脑功能区内的连接影响较小。特别地,采取r TMS联合运动训练,使alpha频段非优势侧中央区与优势侧额叶区(训练前0.141 4±0.102 5,训练后0.217 2±0.134 7,P<0.05)、非优势侧额叶区(训练前0.141 0±0.109 9,训练后0.205 9±0.136 1,P<0.05)的功能连接性显著增加。网络特征结果显示,节点效率在低频段增加、高频段降低,而节点最短路径长度表现出相反的结果,其中gamma2频段在双侧中央区的节点效率(左中央区,实验前0.060 0±0.000 3,实验后0.042 9±0.001 3,P<0.05;右中央区,实验前0.060 7±0.002 3,实验后0.041 9±0.002 4,P<0.05)和最短路径长度(左中央区,实验前18.539 0±0.457 1,实验后28.585 8±1.001 4,P<0.05;右中央区,实验前18.650 8±0.438 6,实验后28.853 0±1.652 6,P<0.05)发生显著性的改变。通过该项研究,加深对r TMS联合运动训练促进运动能力神经机制的理解,为未来探究其对脑卒中、脑损伤患者脑活动的影响提供帮助。

It was reported that repetitive transcranial magnetic stimulation（ r TMS） combined with motor training could improve the motor skill,which could be used in motor rehabilitation after stroke. In this study,the effects of r TMS combined with motor training on brain neural activities were investigated based on the method of brain network. Ten healthy volunteers were recruited. The 1 Hz r TMS over the dominant hemisphere combined with unfamiliar motor training with non-dominant hand subsequently was performed r TMS combinedwith motor training lasted 14 days to improve the motor function of non-dominant hand. Electroencephalography（ EEG） in resting state with eyes closed was recorded before and after r TMS combined with motor training. The functional connectivity was analyzed using the method of phase lag index（ PLI）. We constructed weighted network and calculated the network topology characteristics based on PLI,subsequently. Finally,the signedrank test was used for statistical analysis. We found that the changes of functional connectivity could be detected mainly between functional regions rather than inside regions. The functional connectivity at lower frequency band（ theta and alpha） was significantly increased,and was opposite at higher frequency band（ beta,gamma1 and gamma2）. Furthermore,we found that the r TMS combined with motor training had a significant influence on the functional connectivity between central region in non-dominant hemisphere and dominant frontal regions（ before： 0. 141 4 ± 0. 102 5; after： 0. 217 2 ± 0. 134 7; P〈0. 05） and non-dominant frontal regions（ before： 0. 141 0 ± 0. 109 9; after： 0. 205 9 ± 0. 136 1; P〈0. 05） at alpha frequency. Node efficiency increased at low band and decreased at high band,and node path length was opposite. Specifically,the node efficiency at gamma2 band changed significantly,mainly in central regions of both hemisphere（ left,before： 0. 060 0 ± 0. 000 3; after： 0. 042 9 ± 0. 001 3; P〈0. 05; right,before： 0. 060 7 ± 0. 002 3; after：0. 041 9 ± 0. 002 4; P〈0. 05）,and also the node path length（ left,before： 18. 539 0 ± 0. 457 1; after：28. 585 8 ± 1. 001 4; P〈0. 05; right,before： 18. 650 8 ± 0. 438 6; after： 28. 853 0 ± 1. 652 6; P〈0. 05）.This study was helpful to understand the brain mechanism of r TMS combined with motor training on improvement of motor skill,and comprehend the impact of stroke and brain lesions on brain activities.