Berenson-Allen Center for Noninvasive Brain Stimulation, Division of Cognitive Neurology, Department of Neurology, Beth Israel Deaconess Medical Center, 330 Brookline Ave, Boston, MA, 02215, USA,
Brain Topogr. 2014 Jan;27(1):172-91. doi: 10.1007/s10548-013-0277-y. Epub 2013 Mar 8.
Transcranial magnetic stimulation (TMS) is a noninvasive brain stimulation technique that utilizes magnetic fluxes to alter cortical activity. Continuous theta-burst repetitive TMS (cTBS) results in long-lasting decreases in indices of cortical excitability, and alterations in performance of behavioral tasks. We investigated the effects of cTBS on cortical function via functional connectivity and graph theoretical analysis of EEG data. Thirty-one channel resting-state EEG recordings were obtained before and after 40 s of cTBS stimulation to the left primary motor cortex. Functional connectivity between nodes was assessed in multiple frequency bands using lagged max-covariance, and subsequently thresholded to construct undirected graphs. After cTBS, we find widespread decreases in functional connectivity in the alpha band. There are also simultaneous increases in functional connectivity in the high-beta bands, especially amongst anterior and interhemispheric connections. The analysis of the undirected graphs reveals that interhemispheric and interregional connections are more likely to be modulated after cTBS than local connections. There is also a shift in the topology of network connectivity, with an increase in the clustering coefficient after cTBS in the beta bands, and a decrease in clustering and increase in path length in the alpha band, with the alpha-band connectivity primarily decreased near the site of stimulation. cTBS produces widespread alterations in cortical functional connectivity, with resulting shifts in cortical network topology.
经颅磁刺激（TMS）是一种非侵入性的大脑刺激技术，利用磁通量来改变皮质活动。连续 theta 爆发重复 TMS（cTBS）导致皮质兴奋性的指数持续降低，并改变行为任务的表现。我们通过 EEG 数据的功能连接和图论分析来研究 cTBS 对皮质功能的影响。在对左侧初级运动皮质进行 40 秒 cTBS 刺激之前和之后，获得了 31 通道静息状态 EEG 记录。使用滞后最大协方差在多个频带中评估节点之间的功能连接，然后对其进行阈值处理以构建无向图。在 cTBS 之后，我们发现 alpha 波段的功能连接广泛降低。高 beta 波段的功能连接也同时增加，尤其是在前部和半球间连接中。无向图的分析表明，cTBS 后，半球间和区域间连接比局部连接更有可能被调节。网络连接的拓扑结构也发生了变化，cTBS 后 beta 波段的聚类系数增加，alpha 波段的聚类系数降低，路径长度增加，alpha 波段的连接主要在刺激部位附近减少。cTBS 导致皮质功能连接广泛改变，皮质网络拓扑结构发生变化。
