Emotional numbing in PTSD is associated with lower amygdala reactivity to pain
Emotional numbing in PTSD is associated with lower amygdala reactivity to pain
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DOI：
10.1038/s41386-022-01405-2
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发表时间：
2022-08
影响因子：
7.6
通讯作者：
Nachshon Korem;O. Duek;Ziv Ben-Zion;A. Kaczkurkin;S. Lissek;Temidayo A. Orederu;D. Schiller;I. Harpaz-Rotem;I. Levy
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作者：
Nachshon Korem;O. Duek;Ziv Ben-Zion;A. Kaczkurkin;S. Lissek;Temidayo A. Orederu;D. Schiller;I. Harpaz-Rotem;I. Levy
创伤后应激障碍(PTSD)与痛觉改变有关，即痛阈值升高和更高的疼痛反应。虽然疼痛由生理和情感两部分组成，但情感部分往往被忽视。在PTSD中，对情绪刺激的反应也表现出类似的高阈值反应增加的模式，即情绪麻木。由于情绪麻木和疼痛处理都是由杏仁核调节的，我们的目的是检查被诊断为创伤后应激障碍的人是否比战斗对照组对疼痛的杏仁核激活更低，以及杏仁核对疼痛的反应是否与情绪麻木相关。为此，两个独立的退伍军人样本(原始研究：44个(20个创伤后应激障碍)；概念性复制研究：40个(20个创伤后应激障碍))接受了威胁条件反射，其中条件刺激(CS+；视觉刺激)与非条件刺激(美国；电击)配对。我们将杏仁核活动与CS + US配对和单独呈现的CS+ 进行了对比，并将其与情绪麻木的严重程度相关联。在这两个样本中，创伤后应激障碍组与战斗控制组相比，杏仁核对休克的反应性显著降低。此外，杏仁核的激活与情绪麻木的严重程度呈负相关。这些模式是杏仁核独有的，与控制区域脑岛相比没有出现，脑岛是处理疼痛的关键区域。总而言之，患有创伤后应激障碍的人杏仁核对疼痛的反应较低，并与情绪麻木症状有关。杏仁核对轻微疼痛的低反应性可能导致在创伤后应激障碍中经常观察到的对应激情况的“全有或全无”反应。
Posttraumatic stress disorder (PTSD) is associated with altered pain perception, namely increased pain threshold and higher pain response. While pain consists of physiological and affective components, affective components are often overlooked. Similar patterns of increased threshold-high response in PTSD were shown in response to emotional stimuli, i.e., emotional numbing. As both emotional numbing and pain processing are modulated by the amygdala, we aimed to examine whether individuals diagnosed with PTSD show lower amygdala activation to pain compared with combat controls, and whether the amygdala responses to pain correlates with emotional numbing. To do so, two independent samples of veterans (original study: 44 total (20 PTSD); conceptual replication study: 40 total (20 PTSD)) underwent threat conditioning, where a conditioned stimulus (CS+; visual stimulus) was paired with an unconditioned stimulus (US; electric-shock). We contrasted the amygdala activity to the CS + US pairing with the CS+ presented alone and correlated it with emotional numbing severity. In both samples, the PTSD group showed a robust reduction in amygdala reactivity to shock compared to the Combat Controls group. Furthermore, amygdala activation was negatively correlated with emotional numbing severity. These patterns were unique to the amygdala, and did not appear in comparison to a control region, the insula, a pivotal region for the processing of pain. To conclude, amygdala response to pain is lower in individuals with PTSD, and is associated with emotional numbing symptoms. Lower amygdala reactivity to mild pain may contribute to the “all-or-none” reaction to stressful situations often observed in PTSD.