Prague Psychiatric Centre, Prague, Czech Republic.
Psychol Med. 2010 Sep;40(9):1443-51. doi: 10.1017/S0033291709991619. Epub 2009 Dec 9.
Theta cordance is a novel quantitative electroencephalography (QEEG) measure that correlates with cerebral perfusion. A series of clinical studies has demonstrated that the prefrontal theta cordance value decreases after 1 week of treatment in responders to antidepressants and that this effect precedes clinical improvement. Ketamine, a non-competitive antagonist of N-methyl-D-aspartate (NMDA) receptors, has a unique rapid antidepressant effect but its influence on theta cordance is unknown.
In a double-blind, cross-over, placebo-controlled experiment we studied the acute effect of ketamine (0.54 mg/kg within 30 min) on theta cordance in a group of 20 healthy volunteers.
Ketamine infusion induced a decrease in prefrontal theta cordance and an increase in the central region theta cordance after 10 and 30 min. The change in prefrontal theta cordance correlated with ketamine and norketamine blood levels after 10 min of ketamine infusion.
Our data indicate that ketamine infusion immediately induces changes similar to those that monoamineric-based antidepressants induce gradually. The reduction in theta cordance could be a marker and a predictor of the fast-acting antidepressant effect of ketamine, a hypothesis that could be tested in depressive patients treated with ketamine.
θ 同步是一种新的定量脑电图（QEEG）测量方法，与脑灌注相关。一系列临床研究表明，在抗抑郁药治疗反应者中，经过 1 周的治疗后，前额叶θ 同步值下降，并且这种效应先于临床改善。氯胺酮是 N-甲基-D-天冬氨酸（NMDA）受体的非竞争性拮抗剂，具有独特的快速抗抑郁作用，但它对θ 同步的影响尚不清楚。
在一项双盲、交叉、安慰剂对照实验中，我们研究了氯胺酮（30 分钟内 0.54mg/kg）对 20 名健康志愿者的θ 同步的急性影响。
氯胺酮输注后 10 和 30 分钟，引起前额叶θ 同步减少，中央区域θ 同步增加。氯胺酮输注 10 分钟后，前额叶θ 同步的变化与氯胺酮和去甲氯胺酮的血药浓度相关。
我们的数据表明，氯胺酮输注立即引起类似于单胺类抗抑郁药逐渐引起的变化。θ 同步的减少可能是氯胺酮快速抗抑郁作用的标志物和预测因子，这一假设可以在接受氯胺酮治疗的抑郁症患者中进行测试。
