Sakamoto Hideshi, Fukuda Rin, Okuaki Tomoyuki, Rogers Mark, Kasai Kiyoto, Machida Toru, Shirouzu Ichiro, Yamasue Hidenori, Akiyama Tsuyoshi, Kato Nobumasa
Department of Neuropsychiatry, University of Tokyo, Tokyo, Japan.
Neuroimage. 2005 Jul 1;26(3):813-21. doi: 10.1016/j.neuroimage.2005.02.032. Epub 2005 Apr 7.
Posttraumatic stress disorder (PTSD) has been widely studied, but its neural mechanism is still unclear. The purpose of this study is to identify dysfunctional areas in PTSD throughout the whole brain to help to elucidate the neural mechanisms of PTSD. Sixteen patients with PTSD and sixteen healthy controls participated in this study. Traumatic images under perceptual threshold including scenes of earthquakes, traffic accidents, ambulances, emergency rooms, and crimes were presented to the participants, and brain activation was measured using functional MRI. Functional brain images of both groups were evaluated with random effect analysis for the whole brain. In the control group, activation in the ventral frontoparietal areas correlated significantly with presentation of the masked traumatic stimuli. In the PTSD group, activation was not observed in these areas, but significant activation correlated with the masked traumatic stimuli in the parahippocampal region including the left parahippocampal gyrus and tail of the left hippocampus. These results suggest that in PTSD patients activation in the ventral frontoparietal network associated with visual attention processing is attenuated, while the left hippocampal area associated with episodic and autobiographical memory is abnormally easily activated. This pattern of activation corresponds well to the clinical characteristics of PTSD, in which even slight traumatic stimuli tend to induce intrusive recollection or flashbacks, despite a general decrease in attention and ability to concentrate.
创伤后应激障碍（PTSD）已得到广泛研究，但其神经机制仍不清楚。本研究的目的是确定PTSD患者全脑功能失调的区域，以帮助阐明PTSD的神经机制。16例PTSD患者和16名健康对照者参与了本研究。向参与者呈现低于感知阈值的创伤性图像，包括地震场景、交通事故、救护车、急诊室和犯罪场景，并使用功能磁共振成像测量脑激活情况。对两组的功能性脑图像进行全脑随机效应分析评估。在对照组中，腹侧额顶叶区域的激活与掩蔽创伤性刺激的呈现显著相关。在PTSD组中，这些区域未观察到激活，但在包括左侧海马旁回和左侧海马尾部在内的海马旁区域，显著激活与掩蔽创伤性刺激相关。这些结果表明，PTSD患者中与视觉注意力处理相关的腹侧额顶叶网络的激活减弱，而与情景记忆和自传体记忆相关的左侧海马区域异常容易被激活。这种激活模式与PTSD的临床特征非常吻合，即尽管注意力和集中能力普遍下降，但即使轻微的创伤性刺激也往往会引发侵入性回忆或闪回。
