Mech-Sense, Department of Gastroenterology, Aalborg Hospital, Aalborg University, Aalborg, Denmark.
J Clin Neurophysiol. 2012 Jun;29(3):219-25. doi: 10.1097/WNP.0b013e3182570fd3.
By using a novel brain source modeling approach, where the evoked potential (EP) signal was decomposed with multichannel matching pursuit (MMP) before source localization, we investigated brain generators of EPs after a pain stimulus in the esophagus before and after administration of placebo/morphine. We showed that this new approach of pharmaco-electroencephalogram (EEG) analysis can shed light on subtle changes, which cannot be foreseen from conventional analysis (amplitude/latency/topography).
In this placebo-controlled crossover study, the effects of orally administered morphine (30 mg) on esophageal pain elicited by electrical stimulation were investigated in 9 healthy volunteers. Using new methods (decomposition of the EPs with MMP and clustering) in combination with inverse modeling, we investigated brain sources of the EPs and their time-frequency properties.
Morphine treatment resulted in a shift of the brain sources in the low-frequency range (2-4 Hz) toward the frontal cortex during the first 300 milliseconds after stimulus, whereas active brain sources after placebo treatment remained stable.
Decomposing the EPs into the original brain generators showed that morphine mainly changes the low frequency electrical activity in the frontal brain area. This method can be used to increase the basic understanding of the opioid effect on the brain's processing of pain and eventually identify biomarkers of analgesia in experimental pain models.
通过使用一种新的脑源建模方法，即在源定位之前，使用多通道匹配追踪（MMP）对诱发电位（EP）信号进行分解，我们研究了在给予安慰剂/吗啡前后食管疼痛刺激后 EP 的脑发生器。我们表明，这种新的药物-脑电图（EEG）分析方法可以揭示细微的变化，这些变化无法从常规分析（幅度/潜伏期/地形）中预见。
在这项安慰剂对照交叉研究中，研究了 9 名健康志愿者口服吗啡（30 毫克）对电刺激引起的食管疼痛的影响。使用新方法（MMP 对 EP 的分解和聚类）结合逆建模，我们研究了 EP 的脑源及其时频特性。
吗啡治疗导致刺激后 300 毫秒内低频范围（2-4 Hz）的脑源向额叶皮层转移，而安慰剂治疗后的活跃脑源保持稳定。
将 EP 分解为原始脑发生器表明，吗啡主要改变额叶大脑区域的低频电活动。这种方法可用于增加对阿片类药物对大脑处理疼痛的影响的基本理解，并最终确定实验性疼痛模型中镇痛的生物标志物。
