Zuchowicz Urszula, Wozniak-Kwasniewska Agata, Szekely David, Olejarczyk Elzbieta, David Olivier
Department of Automatics and Biomedical Engineering, AGH University of Science and Technology, Cracow, Poland.
Inserm, U1216, Grenoble, France.
Front Neurosci. 2019 Jan 14;12:1037. doi: 10.3389/fnins.2018.01037. eCollection 2018.
The main objective of this work was to study the impact of repetitive Transcranial Magnetic Stimulation (rTMS) treatment on brain activity in 8 patients with major depressive disorder (MDD) and 10 patients with bipolar disorder (BP). Changes due to rTMS stimulation of the left dorsolateral prefrontal cortex (DLPFC) were investigated considering separately responders and non-responders to therapy in each of both groups. The aim of the research is to determine whether non-responders differ from responders suffered from both diseases, as well as if any change occurred due to rTMS across consecutive rTMS sessions. The graph-theory-based connectivity analysis of non-linearity measure of phase interdependencies-Phase Locking Value (PLV)-was examined from EEG data. The approximately 15-min EEG recordings from each of participants were recorded before and after 1st, 10th, and 20th session, respectively. PLV calculated from data was analyzed using principal graph theory indices (strength and degree) within five physiological frequency bands and in individual channels separately. The impact of rTMS on the EEG connectivity in every group of patients evaluated by PLV was assessed. Each of four groups reacted differently to rTMS treatment. The strength and degree of PLV increased in gamma band in both groups of responders. Moreover, an increase of indices in beta band for BP-responders was observed. While, in MDD-non-responders the indices decreased in gamma band and increased in beta band. Moreover, the index strength was lower in alpha band for BP- non-responders. The rTMS stimulation caused topographically specific changes, i.e., the increase of the activity in the left DLPFC as well as in other brain regions such as right parieto-occipital areas. The analysis of PLV allowed for evaluation of the rTMS impact on the EEG activity in each group of patients. The changes of PLV under stimulation might be a good indicator of response to depression treatment permitting to improve the effectiveness of therapy.
这项工作的主要目的是研究重复经颅磁刺激（rTMS）治疗对8例重度抑郁症（MDD）患者和10例双相情感障碍（BP）患者大脑活动的影响。研究分别考虑了两组中对治疗有反应者和无反应者，调查了左侧背外侧前额叶皮质（DLPFC）经rTMS刺激后的变化。该研究的目的是确定两种疾病的无反应者与有反应者是否存在差异，以及在连续的rTMS疗程中rTMS是否导致了任何变化。通过脑电图（EEG）数据，对基于图论的相位相互依存性非线性测量——锁相值（PLV）进行了连通性分析。分别在第1次、第10次和第20次疗程前后，记录了每位参与者约15分钟的EEG。根据数据计算得到的PLV，分别在五个生理频带内和各个通道中，使用主图论指标（强度和度）进行分析。评估了PLV评估的rTMS对每组患者EEG连通性的影响。四组中的每组对rTMS治疗的反应都不同。两组有反应者的PLV强度和度在γ波段均增加。此外，观察到BP有反应者的β波段指标增加。而在MDD无反应者中，γ波段指标下降，β波段指标增加。此外，BP无反应者的α波段指标强度较低。rTMS刺激引起了地形学上的特定变化，即左侧DLPFC以及其他脑区（如右侧顶枕区）的活动增加。对PLV的分析有助于评估rTMS对每组患者EEG活动的影响。刺激下PLV的变化可能是抑郁症治疗反应的良好指标，有助于提高治疗效果。
