Olejarczyk Elzbieta, Jozwik Adam, Valiulis Vladas, Dapsys Kastytis, Gerulskis Giedrius, Germanavicius Arunas
Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland.
Faculty of Physics and Applied Informatics, University in Łódź, Łódź, Poland.
Front Neuroinform. 2021 Apr 8;15:651082. doi: 10.3389/fninf.2021.651082. eCollection 2021.
The objective of this work was to demonstrate the usefulness of a novel statistical method to study the impact of transcranial magnetic stimulation (TMS) on brain connectivity in patients with depression using different stimulation protocols, i.e., 1 Hz repetitive TMS over the right dorsolateral prefrontal cortex (DLPFC) (protocol G1), 10 Hz repetitive TMS over the left DLPFC (G2), and intermittent theta burst stimulation (iTBS) consisting of three 50 Hz burst bundle repeated at 5 Hz frequency (G3).
Electroencephalography (EEG) connectivity analysis was performed using Directed Transfer Function (DTF) and a set of 21 indices based on graph theory. The statistical analysis of graph-theoretic indices consisted of a combination of the -NN rule, the leave-one-out method, and a statistical test using a 2 × 2 contingency table.
Our new statistical approach allowed for selection of the best set of graph-based indices derived from DTF, and for differentiation between conditions (i.e., before and after TMS) and between TMS protocols. The effects of TMS was found to differ based on frequency band.
A set of four brain asymmetry measures were particularly useful to study protocol- and frequency-dependent effects of TMS on brain connectivity.
The new approach would allow for better evaluation of the therapeutic effects of TMS and choice of the most appropriate stimulation protocol.
本研究的目的是证明一种新型统计方法的实用性，该方法用于研究经颅磁刺激（TMS）对抑郁症患者脑连接性的影响，采用不同的刺激方案，即右侧背外侧前额叶皮质（DLPFC）的1赫兹重复经颅磁刺激（方案G1）、左侧DLPFC的10赫兹重复经颅磁刺激（G2）以及由以5赫兹频率重复的三个50赫兹脉冲串组成的间歇性theta爆发刺激（iTBS）（G3）。
使用定向传递函数（DTF）和一组基于图论的21个指标进行脑电图（EEG）连接性分析。图论指标的统计分析包括 -NN规则、留一法以及使用2×2列联表的统计检验的组合。
我们的新统计方法允许从DTF中选择最佳的基于图的指标集，并区分不同条件（即TMS前后）以及不同的TMS方案。发现TMS的效果因频段而异。
一组四个脑不对称测量指标对于研究TMS对脑连接性的方案依赖性和频率依赖性效应特别有用。
新方法将有助于更好地评估TMS的治疗效果并选择最合适的刺激方案。
