Electroencephalographic (EEG) Burst Suppression (BSUPP) is a discontinuous pattern characterized by episodes of low voltage disrupted by bursts of cortical synaptic activity. It can occur while delivering high-dose anesthesia. Current research suggests an association between BSUPP and the occurrence of postoperative delirium in the post-anesthesia care unit (PACU) and beyond. We investigated burst micro-architecture to further understand how age influences the neurophysiology of this pharmacologically-induced state. We analyzed a subset of EEG recordings (n = 102) taken from a larger data set previously published. We selected the initial burst that followed a visually identified “silent second,” i.e., at least 1 s of iso-electricity of the EEG during propofol induction. We derived the (normalized) power spectral density [(n)PSD], the alpha band power, the maximum amplitude, the maximum slope of the EEG as well as the permutation entropy (PeEn) for the first 1.5 s of the initial burst of each patient. In the old patients >65 years, we observed significantly lower (p < 0.001) EEG power in the 1–15 Hz range. In general, their EEG contained a significantly higher amount of faster oscillations (>15 Hz). Alpha band power (p < 0.001), EEG amplitude (p = 0.001), and maximum EEG slope (p = 0.045) all significantly decreased with age, whereas PeEn increased (p = 0.008). Hence, we can describe an age-related change in features during EEG burst suppression. Sub-group analysis revealed no change in results based on pre-medication. These EEG changes add knowledge to the impact of age on cortical synaptic activity. In addition to a reduction in EEG amplitude, age-associated burst features can complicate the identification of excessive anesthetic administration in patients under general anesthesia. Knowledge of these neurophysiologic changes may not only improve anesthesia care through improved detection of burst suppression but might also provide insight into changes in neuronal network organization in patients at risk for age-related neurocognitive problems.

中文翻译：

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麻醉诱导爆发抑制期间爆发活动的年龄相关脑电图特征

脑电图 (EEG) 爆发抑制 (BSUPP) 是一种不连续模式，其特征是低电压发作被皮质突触活动的爆发中断。它可能在提供高剂量麻醉时发生。目前的研究表明 BSUPP 与麻醉后监护室 (PACU) 及其他地方的术后谵妄发生之间存在关联。我们研究了突发微架构，以进一步了解年龄如何影响这种药理学诱导状态的神经生理学。我们分析了从先前发布的更大数据集中获取的 EEG 记录子集 (n = 102)。我们选择了在视觉识别的“无声秒”之后的初始爆发，即丙泊酚诱导期间脑电图的至少 1 秒等电。我们推导出（归一化）功率谱密度 [(n)PSD]，每个患者初始突发的前 1.5 秒的 alpha 波段功率、最大幅度、EEG 的最大斜率以及排列熵 (PeEn)。在 65 岁以上的老年患者中，我们观察到 1-15 Hz 范围内的 EEG 功率显着降低（p < 0.001）。一般来说，他们的脑电图包含大量更快的振荡（> 15 Hz）。Alpha 波段功率 (p < 0.001)、EEG 振幅 (p = 0.001) 和最大 EEG 斜率 (p = 0.045) 均随年龄显着降低，而 PeEn 增加 (p = 0.008)。因此，我们可以描述 EEG 爆发抑制期间与年龄相关的特征变化。亚组分析显示基于预先用药的结果没有变化。这些脑电图变化增加了年龄对皮层突触活动影响的知识。除了脑电图振幅的降低，与年龄相关的爆发特征会使全身麻醉下患者麻醉过度给药的识别复杂化。了解这些神经生理学变化不仅可以通过改进对爆发抑制的检测来改善麻醉护理，还可以深入了解有年龄相关神经认知问题风险的患者的神经元网络组织的变化。