Borich Michael R, Wheaton Lewis A, Brodie Sonia M, Lakhani Bimal, Boyd Lara A
Division of Physical Therapy, Department of Rehabilitation Medicine, Emory University School of Medicine, 1441 Clifton Rd NE, R228, Atlanta, GA 30322 USA.
School of Applied Physiology, Georgia Institute of Technology, 555 14th St., Room 1309E, Atlanta, GA 30332, USA.
Neurosci Lett. 2016 Apr 8;618:25-30. doi: 10.1016/j.neulet.2016.02.047. Epub 2016 Mar 3.
TMS-evoked cortical responses can be measured using simultaneous electroencephalography (TMS-EEG) to directly quantify cortical connectivity in the human brain. The purpose of this study was to evaluate interhemispheric cortical connectivity between the primary motor cortices (M1s) in participants with chronic stroke and controls using TMS-EEG. Ten participants with chronic stroke and four controls were tested. TMS-evoked responses were recorded at rest and during a typical TMS assessment of transcallosal inhibition (TCI). EEG recordings from peri-central gyral electrodes (C3 and C4) were evaluated using imaginary phase coherence (IPC) analyses to quantify levels of effective interhemispheric connectivity. Significantly increased TMS-evoked beta (15-30Hz frequency range) IPC was observed in the stroke group during ipsilesional M1 stimulation compared to controls during TCI assessment but not at rest. TMS-evoked beta IPC values were associated with TMS measures of transcallosal inhibition across groups. These results suggest TMS-evoked EEG responses can index abnormal effective interhemispheric connectivity in chronic stroke.
经颅磁刺激（TMS）诱发的皮质反应可通过同步脑电图（TMS-EEG）进行测量，以直接量化人脑的皮质连接性。本研究的目的是使用TMS-EEG评估慢性中风患者和对照组初级运动皮质（M1）之间的半球间皮质连接性。对10名慢性中风患者和4名对照组进行了测试。在静息状态和典型的经胼胝体抑制（TCI）TMS评估期间记录TMS诱发的反应。使用虚部相位相干（IPC）分析评估中央周围回电极（C3和C4）的脑电图记录，以量化有效的半球间连接水平。在TCI评估期间，与对照组相比，中风组在患侧M1刺激期间观察到TMS诱发的β波（15-30Hz频率范围）IPC显著增加，但在静息状态下未观察到。跨组的TMS诱发的β波IPC值与经胼胝体抑制的TMS测量值相关。这些结果表明，TMS诱发的脑电图反应可反映慢性中风中异常的有效半球间连接性。
