Low Frontal Alpha Power Is Associated With the Propensity for Burst Suppression: An Electroencephalogram Phenotype for a "Vulnerable Brain".
Low Frontal Alpha Power Is Associated With the Propensity for Burst Suppression: An Electroencephalogram Phenotype for a "Vulnerable Brain".
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DOI：
10.1213/ane.0000000000004781
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发表时间：
2020-11
影响因子：
5.7
通讯作者：
Purdon PL
中科院分区：
文献类型：
--
作者：
Shao YR;Kahali P;Houle TT;Deng H;Colvin C;Dickerson BC;Brown EN;Purdon PL
最近的一些研究报告了术中猝发抑制和术后精神错乱之间的关系。这些研究表明，麻醉诱导的突发抑制可能是潜在的大脑脆弱性的一个指标。异丙酚和七氟醚复合麻醉下的脑电(EEG)的一个显著特征是额部α振荡。众所周知，这种额叶阿尔法振荡在衰老过程中会显着下降，并且是由特别容易发生与年龄相关的神经退化的前额脑区域产生的。鉴于爆发抑制和额叶阿尔法振荡都与大脑脆弱性有关，我们假设麻醉诱导的额叶阿尔法功率也可能与爆发抑制有关。我们分析了先前报道的一组患者的脑电数据，其中155名患者接受异丙酚(n=60)或七氟醚(n=95)作为主要麻醉剂。我们计算了稳定麻醉维持期间的脑电频谱，并确定在麻醉期间是否发生猝发抑制。我们用Logistic回归分析了猝发抑制与α功率之间的关系。我们提出了5种不同的模型，由与爆发抑制相关的潜在因素的不同组合组成：(1)由阿尔法功率组成的基本模型；(2)由阿尔法功率、年龄和药物剂量信息组成的扩展机制模型；(3)由阿尔法功率、低血压和其他混杂组成的临床混杂因素模型；(4)只包括阿尔法功率和异丙酚推注的简化模型；以及(5)由所有这些变量组成的完整模型，以控制尽可能多的混杂。所有模型都显示了阿尔法功率和突发抑制之间一致的显著关联，同时对不同的协变量集进行了调整，所有这些都具有一致的影响大小估计。使用简化模型，我们发现阿尔法功率每降低一分贝，经历爆发抑制的几率就增加1.33倍。在这项研究中，我们展示了麻醉诱导的额叶阿尔法能量的降低如何与突发抑制倾向的增加有关，这种方式捕捉到了患者实际年龄以上和之外的个性化信息。额叶阿尔法频段功率较低与较高的突发抑制倾向密切相关，因此，术后神经认知障碍的潜在风险较高。我们假设，在麻醉状态下，额叶阿尔法功率低和爆发抑制倾向增加共同表征了“脆弱脑”的表型，这可能与大脑新陈代谢、认知和脑老化有机械联系。
A number of recent studies have reported an association between intraoperative burst suppression and postoperative delirium. These studies suggest that anesthesia-induced burst suppression may be an indicator of underlying brain vulnerability. A prominent feature of electroencephalogram (EEG) under propofol and sevoflurane anesthesia is the frontal alpha oscillation. This frontal alpha oscillation is known to decline significantly during aging and is generated by prefrontal brain regions that are particularly prone to age-related neurodegeneration. Given that burst suppression and frontal alpha oscillations are both associated with brain vulnerability, we hypothesized that anesthesia-induced frontal alpha power could also be associated with burst suppression. We analyzed EEG data from a previously reported cohort in which 155 patients received propofol (n = 60) or sevoflurane (n = 95) as the primary anesthetic. We computed the EEG spectrum during stable anesthetic maintenance and identified whether or not burst suppression occurred during the anesthetic. We characterized the relationship between burst suppression and alpha power using logistic regression. We proposed 5 different models consisting of different combinations of potential contributing factors associated with burst suppression: (1) a Base Model consisting of alpha power; (2) an Extended Mechanistic Model consisting of alpha power, age, and drug dosing information; (3) a Clinical Confounding Factors Model consisting of alpha power, hypotension, and other confounds; (4) a Simplified Model consisting only of alpha power and propofol bolus administration; and (5) a Full Model consisting of all of these variables to control for as much confounding as possible. All models show a consistent significant association between alpha power and burst suppression while adjusting for different sets of covariates, all with consistent effect size estimates. Using the Simplified Model, we found that for each decibel decrease in alpha power, the odds of experiencing burst suppression increased by 1.33-fold. In this study, we show how a decrease in anesthesia-induced frontal alpha power is associated with an increased propensity for burst suppression, in a manner that captures individualized information above and beyond a patient’s chronological age. Lower frontal alpha band power is strongly associated with higher propensity for burst suppression and, therefore, potentially higher risk of postoperative neurocognitive disorders. We hypothesize that low frontal alpha power and increased propensity for burst suppression together characterize a “vulnerable brain” phenotype under anesthesia that could be mechanistically linked to brain metabolism, cognition, and brain aging.