Department of Anesthesiology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA.
Department of Anesthesiology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA; Department of Neurology, David Geffen School of Medicine at University of California, Los Angeles, Los Angeles, CA, USA.
Clin Neurophysiol. 2022 Oct;142:125-132. doi: 10.1016/j.clinph.2022.07.493. Epub 2022 Jul 30.
Periods of low-amplitude electroencephalographic (EEG) signal (quiescence) are present during both anesthetic-induced burst suppression (BS) and postictal generalized electroencephalographic suppression (PGES). PGES following generalized seizures induced by electroconvulsive therapy (ECT) has been previously linked to antidepressant response. The commonality of quiescence during both BS and PGES motivated trials to recapitulate the antidepressant effects of ECT using high doses of anesthetics. However, there have been no direct electrographic comparisons of these quiescent periods to address whether these are distinct entities.
We compared periods of EEG quiescence recorded from two human studies: BS induced in 29 healthy adult volunteers by isoflurane general anesthesia and PGES in 11 patients undergoing right unilateral ECT for treatment-resistant depression. An automated algorithm allowed detection of EEG quiescence based on a 10-microvolt amplitude threshold. Spatial, spectral, and temporal analyses compared quiescent epochs during BS and PGES.
The median (interquartile range) voltage for quiescent periods during PGES was greater than during BS (1.81 (0.22) microvolts vs 1.22 (0.33) microvolts, p < 0.001). Relative power was greater for quiescence during PGES than BS for the 1-4 Hz delta band (p < 0.001), at the expense of power in the theta (4-8 Hz, p < 0.001), beta (13-30 Hz, p = 0.04) and gamma (30-70 Hz, p = 0.006) frequency bands. Topographic analyses revealed that amplitude across the scalp was consistently higher for quiescent periods during PGES than BS, whose voltage was within the noise floor.
Quiescent epochs during PGES and BS have distinct patterns of EEG signals across voltage, frequency, and spatial domains.
Quiescent epochs during PGES and BS, important neurophysiological markers for clinical outcomes, are shown to have distinct voltage and frequency characteristics.
在麻醉诱导的爆发抑制（BS）和癫痫后广泛脑电图抑制（PGES）期间，都存在低幅度脑电图（EEG）信号的时期（静止期）。先前已经将电惊厥疗法（ECT）引起的全身性癫痫发作后的 PGES 与抗抑郁反应联系起来。BS 和 PGES 期间的静止期的共性促使人们尝试使用高剂量的麻醉剂来重现 ECT 的抗抑郁作用。然而，尚未对这些静止期进行直接的脑电图比较，以确定它们是否为不同的实体。
我们比较了两项人类研究中记录的 EEG 静止期：29 名健康成年志愿者接受异氟烷全身麻醉诱导的 BS 和 11 名接受右侧单侧 ECT 治疗难治性抑郁症的患者的 PGES。自动算法允许根据 10 微伏的振幅阈值检测 EEG 静止期。空间、频谱和时间分析比较了 BS 和 PGES 期间的静止期。
PGES 期间的静止期的中位数（四分位距）电压大于 BS 期间（1.81（0.22）微伏与 1.22（0.33）微伏，p < 0.001）。PGES 期间的静止期的相对功率大于 BS 期间的 delta 频段（1-4 Hz）（p < 0.001），而 theta 频段（4-8 Hz，p < 0.001）、beta 频段（13-30 Hz，p = 0.04）和 gamma 频段（30-70 Hz，p = 0.006）的功率降低。拓扑分析显示，PGES 期间的静止期的头皮上的振幅始终高于 BS 期间的静止期，BS 期间的电压处于噪声范围内。
PGES 和 BS 期间的静止期在电压、频率和空间域都有明显的 EEG 信号模式。
PGES 和 BS 期间的静止期是临床结果的重要神经生理学标志物，显示出明显的电压和频率特征。
