Electroencephalogram signatures of ketamine anesthesia-induced unconsciousness.
Electroencephalogram signatures of ketamine anesthesia-induced unconsciousness.
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DOI：
10.1016/j.clinph.2016.03.005
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发表时间：
2016-06
期刊：
影响因子：
--
通讯作者：
Purdon PL
中科院分区：
文献类型：
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作者：
Akeju O;Song AH;Hamilos AE;Pavone KJ;Flores FJ;Brown EN;Purdon PL
氯胺酮是一种n -甲基- d -天冬氨酸受体拮抗剂，通常用作全身麻醉剂。然而，解释氯胺酮引起的人类无意识的回路水平机制尚未明确定义。额-顶叶网络连接的中断被认为是解释这种大脑状态的一种机制。然而，这一机制最近在醒着患者的亚麻醉剂量氯胺酮中得到证实。因此，我们研究氯胺酮引起的无意识是否有脑电图标记。我们回顾性研究了12例接受氯胺酮全麻诱导的患者的脑电图。利用功率谱和相干性方法分析脑电动态。在给予大剂量氯胺酮诱导昏迷后，我们观察到一个“伽马爆发”脑电图模式，包括交替的慢三角洲（0.1-4 Hz）和伽马（~27-40 Hz）振荡。这种模式也与θ振荡增加（~4-8赫兹）和α / β振荡减少（~10-24赫兹）有关。氯胺酮引起的无意识与脑电图的伽马暴模式有关。我们假设伽马爆发模式是一种丘脑皮质节律，基于先前从猫神经生理实验中获得的见解。这种氯胺酮引起的无意识的脑电图特征可能为全身麻醉引起的大脑状态提供新的见解。
Ketamine is an N-methyl-D-aspartate receptor antagonist commonly administered as a general anesthetic. However, circuit level mechanisms to explain ketamine-induced unconsciousness in humans are yet to be clearly defined. Disruption of frontal-parietal network connectivity has been proposed as a mechanism to explain this brain state. However, this mechanism was recently demonstrated at subanesthetic doses of ketamine in awake-patients. Therefore we investigated whether there is an electroencephalogram (EEG) marker for ketamine-induced unconsciousness. We retrospectively studied the EEG in 12 patients who received ketamine for the induction of general anesthesia. We analyzed the EEG dynamics using power spectral and coherence methods. Following the administration of a bolus dose of ketamine to induce unconsciousness, we observed a “gamma burst” EEG pattern that consisted of alternating slow-delta (0.1-4 Hz) and gamma (~27-40 Hz) oscillations. This pattern was also associated with increased theta oscillations (~4-8 Hz) and decreased alpha/beta oscillations (~10-24 Hz). Ketamine-induced unconsciousness is associated with a gamma burst EEG pattern. We postulate that the gamma burst pattern is a thalamocortical rhythm based on insights previously obtained from cat neurophysiological experiments. This EEG signature of ketamine-induced unconsciousness may offer new insights into general anesthesia induced brain states.