Vlcek Premysl, Bares Martin, Novak Tomas, Brunovsky Martin
National Institute of Mental Health, Klecany, Czechia.
Third Faculty of Medicine, Charles University, Prague, Czechia.
Front Psychiatry. 2020 Feb 27;11:83. doi: 10.3389/fpsyt.2020.00083. eCollection 2020.
Repetitive transcranial magnetic stimulation (rTMS) is an effective treatment for depressive disorder, with outcomes approaching 45-55% response and 30-40% remission. Eligible predictors of treatment outcome, however, are still lacking. Few studies have investigated quantitative electroencephalography (QEEG) parameters as predictors of rTMS treatment outcome and none of them have addressed the source localization techniques to predict the response to low-frequency rTMS (LF rTMS). We investigated electrophysiological differences based on scalp EEG data and inverse solution method, exact low-resolution brain electromagnetic tomography (eLORETA), between responders and non-responders to LF rTMS in resting brain activity recorded prior to the treatment. Twenty-five unmedicated depressive patients (mean age of 45.7 years, 20 females) received a 4-week treatment of LF rTMS (1 Hz; 20 sessions per 600 pulses; 100% of the motor threshold) over the right dorsolateral prefrontal cortex. Comparisons between responders (≥50% reduction in Montgomery-Åsberg Depression Rating Scale score) and non-responders were made at baseline for measures of eLORETA current density, spectral absolute power, and inter-hemispheric and intra-hemispheric EEG asymmetry. Responders were found to have lower current source densities in the alpha-2 and beta-1 frequency bands bilaterally (with predominance on the left side) in the inferior, medial, and middle frontal gyrus, precentral gyrus, cingulate gyrus, anterior cingulate, and insula. The most pronounced difference was found in the left middle frontal gyrus for alpha-2 and beta-1 bands (p < 0.05). Using a spectral absolute power analysis, we found a negative correlation between the absolute power in beta and theta frequency bands on the left frontal electrode F7 and the change in depressive symptomatology. None of the selected asymmetries significantly differentiated responders from non-responders in any frequency band. Pre-treatment reduction of alpha-2 and beta-1 sources, but not QEEG asymmetry, was found in patients with major depressive disorder who responded to LF rTMS treatment. Prospective trials with larger groups of subjects are needed to further validate these findings.
重复经颅磁刺激（rTMS）是治疗抑郁症的一种有效方法，有效率达45%-55%，缓解率达30%-40%。然而，目前仍缺乏治疗结果的合格预测指标。很少有研究将定量脑电图（QEEG）参数作为rTMS治疗结果的预测指标，且均未涉及用于预测低频rTMS（LF rTMS）反应的源定位技术。我们基于头皮脑电图数据和精确低分辨率脑电磁断层成像（eLORETA）的逆解方法，研究了治疗前静息脑活动中LF rTMS治疗反应者与无反应者之间的电生理差异。25名未服药的抑郁症患者（平均年龄45.7岁，20名女性）接受了为期4周的右侧背外侧前额叶皮质LF rTMS治疗（1赫兹；每600次脉冲20次治疗；运动阈值的100%）。在基线时，对反应者（蒙哥马利-奥斯伯格抑郁量表评分降低≥50%）和无反应者进行比较，测量eLORETA电流密度、频谱绝对功率以及半球间和半球内脑电图不对称性。结果发现，反应者双侧α-2和β-1频段（左侧更明显）在额下回、额中回、额内侧回、中央前回、扣带回、前扣带回和岛叶的电流源密度较低。α-2和β-1频段在左侧额中回的差异最为显著（p<0.05）。通过频谱绝对功率分析，我们发现左侧额电极F7上β和θ频段的绝对功率与抑郁症状变化呈负相关。在任何频段中，所选的不对称性均未显著区分反应者和无反应者。对LF rTMS治疗有反应的重度抑郁症患者在治疗前出现α-2和β-1源减少，但QEEG不对称性未出现减少。需要进行更大样本量的前瞻性试验来进一步验证这些发现。
