Department of Neuroscience, Feil Family Brain Mind Research Institute, Weill Cornell Medicine, New York, NY 10065.
Department of Brain and Cognitive Sciences, Institute for Medical Engineering and Science and Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA 02139.
Proc Natl Acad Sci U S A. 2022 Nov 16;119(46):e2120221119. doi: 10.1073/pnas.2120221119. Epub 2022 Nov 7.
The COVID-19 pandemic has created a large population of patients who are slow to recover consciousness following mechanical ventilation and sedation in the intensive care unit. Few clinical scenarios are comparable. Possible exceptions are the rare patients in post-cardiac arrest coma with minimal to no structural brain injuries who recovered cognitive and motor functions after prolonged delays. A common electroencephalogram (EEG) signature seen in these patients is burst suppression [8]. Biophysical modeling has shown that burst suppression is likely a signature of a neurometabolic state that preserves basic cellular function "during states of lowered energy availability." These states likely act as a brain protective mechanism [9]. Similar EEG patterns are observed in the anoxia resistant painted turtle [24]. We present a conceptual analysis to interpret the brain state of COVID-19 patients suffering prolonged recovery of consciousness. We begin with the Ching model and integrate findings from other clinical scenarios and studies of the anoxia-tolerant physiology of the painted turtle. We postulate that prolonged recovery of consciousness in COVID-19 patients could reflect the effects of modest hypoxic injury to neurons and the unmasking of latent neuroprotective mechanisms in the human brain. This putative protective down-regulated state appears similar to that observed in the painted turtle and suggests new approaches to enhancing coma recovery [12].
在 COVID-19 大流行期间,大量患者在重症监护病房接受机械通气和镇静后,意识恢复缓慢。这种情况比较少见。可能的例外是罕见的心脏停搏后昏迷患者,这些患者的大脑结构损伤极小或没有,在长时间延迟后恢复了认知和运动功能。这些患者常见的脑电图 (EEG) 特征是爆发抑制[8]。生物物理建模表明,爆发抑制可能是一种神经代谢状态的特征,这种状态“在能量供应降低的情况下”维持基本的细胞功能。这些状态可能起到脑保护机制的作用[9]。在耐缺氧的彩绘龟中也观察到类似的 EEG 模式[24]。我们提出了一个概念分析来解释 COVID-19 患者意识恢复缓慢的脑状态。我们从 Ching 模型开始,并整合了来自其他临床情况和耐缺氧生理研究的发现。我们假设 COVID-19 患者意识恢复缓慢可能反映了神经元轻度缺氧损伤的影响,以及人类大脑中潜在神经保护机制的显现。这种潜在的保护性下调状态类似于在彩绘龟中观察到的状态,并为增强昏迷恢复提供了新的方法[12]。