Shin L M, McNally R J, Kosslyn S M, Thompson W L, Rauch S L, Alpert N M, Metzger L J, Lasko N B, Orr S P, Pitman R K
Department of Psychiatry, Massachusetts General Hospital, Boston, USA.
Am J Psychiatry. 1999 Apr;156(4):575-84. doi: 10.1176/ajp.156.4.575.
The purpose of this study was to determine whether anterior limbic and paralimbic regions of the brain are differentially activated during the recollection and imagery of traumatic events in trauma-exposed individuals with and without posttraumatic stress disorder (PTSD).
Positron emission tomography (PET) was used to measure normalized regional cerebral blood flow (CBF) in 16 women with histories of childhood sexual abuse: eight with current PTSD and eight without current PTSD. In separate script-driven imagery conditions, participants recalled and imagined traumatic and neutral autobiographical events. Psychophysiologic responses and subjective ratings of emotional state were measured for each condition.
In the traumatic condition versus the neutral control conditions, both groups exhibited regional CBF increases in orbitofrontal cortex and anterior temporal poles; however, these increases were greater in the PTSD group than in the comparison group. The comparison group exhibited regional CBF increases in insular cortex and anterior cingulate gyrus; increases in anterior cingulate gyrus were greater in the comparison group than in the PTSD group. Regional CBF decreases in bilateral anterior frontal regions were greater in the PTSD group than in the comparison group, and only the PTSD group exhibited regional CBF decreases in left inferior frontal gyrus.
The recollection and imagery of traumatic events versus neutral events was accompanied by regional CBF increases in anterior paralimbic regions of the brain in trauma-exposed individuals with and without PTSD. However, the PTSD group had greater increases in orbitofrontal cortex and anterior temporal pole, whereas the comparison group had greater increases in anterior cingulate gyrus.
本研究旨在确定在有或无创伤后应激障碍（PTSD）的受创伤个体回忆和想象创伤事件时，大脑的前边缘和边缘旁区域是否存在差异激活。
采用正电子发射断层扫描（PET）测量16名有童年性虐待史女性的标准化局部脑血流量（CBF）：8名患有当前PTSD，8名无当前PTSD。在不同的脚本驱动想象条件下，参与者回忆并想象创伤性和中性的自传体事件。对每种条件测量心理生理反应和情绪状态的主观评分。
与中性对照条件相比，在创伤条件下，两组在眶额皮质和颞前极均表现出局部CBF增加；然而，PTSD组的增加幅度大于对照组。对照组在岛叶皮质和前扣带回表现出局部CBF增加；前扣带回的增加在对照组大于PTSD组。PTSD组双侧前额叶区域的局部CBF减少幅度大于对照组，且只有PTSD组在左下额叶回表现出局部CBF减少。
在有或无PTSD的受创伤个体中，创伤性事件与中性事件的回忆和想象均伴随着大脑前边缘旁区域局部CBF增加。然而，PTSD组在眶额皮质和颞前极增加幅度更大，而对照组在前扣带回增加幅度更大。
