Hong J-Y, Naliboff B, Labus J S, Gupta A, Kilpatrick L A, Ashe-McNalley C, Stains J, Heendeniya N, Smith S R, Tillisch K, Mayer E A
Oppenheimer Center for Neurobiology of Stress, University of California, Los Angeles, CA, USA.
Department of Medicine, University of California, Los Angeles, CA, USA.
Neurogastroenterol Motil. 2016 Jan;28(1):127-38. doi: 10.1111/nmo.12710. Epub 2015 Nov 3.
A majority of the subjects with irritable bowel syndrome (IBS) show increased behavioral and brain responses to expected and delivered aversive visceral stimuli during controlled rectal balloon distension, and during palpation of the sigmoid colon. We aimed to determine if altered brain responses to cued and uncued pain expectation are also seen in the context of a noxious somatic pain stimulus applied to the same dermatome as the sigmoid colon.
A task-dependent functional magnetic resonance imaging technique was used to investigate the brain activity of 37 healthy controls (18 females) and 37 IBS subjects (21 females) during: (i) a cued expectation of an electric shock to the abdomen vs a cued safe condition; and (ii) an uncued cross-hair condition in which the threat is primarily based on context vs a cued safe condition.
Regions within the salience, attention, default mode, and emotional arousal networks were more activated by the cued abdominal threat condition and the uncued condition than in the cued safe condition. During the uncued condition contrasted to the cued safe condition, IBS subjects (compared to healthy control subjects) showed greater brain activations in the affective (amygdala, anterior insula) and attentional (middle frontal gyrus) regions, and in the thalamus and precuneus. These disease-related differences were primarily seen in female subjects.
CONCLUSIONS & INFERENCES: The observed greater engagement of cognitive and emotional brain networks in IBS subjects during contextual threat may reflect the propensity of IBS subjects to overestimate the likelihood and severity of future abdominal pain.
大多数肠易激综合征（IBS）患者在直肠气囊扩张控制期间以及乙状结肠触诊期间，对预期和实际施加的厌恶性内脏刺激表现出行为和大脑反应增强。我们旨在确定在对与乙状结肠相同皮节施加有害躯体疼痛刺激的情况下，对提示性和非提示性疼痛预期的大脑反应改变是否也会出现。
采用任务依赖性功能磁共振成像技术，研究37名健康对照者（18名女性）和37名IBS患者（21名女性）在以下情况时的大脑活动：（i）提示性预期腹部电击与提示性安全状态；（ii）非提示性十字准线状态，其中威胁主要基于情境与提示性安全状态。
与提示性安全状态相比，提示性腹部威胁状态和非提示性状态下，突显、注意力、默认模式和情绪唤醒网络内的区域激活更明显。与提示性安全状态相比，在非提示性状态下，IBS患者（与健康对照者相比）在情感（杏仁核、前岛叶）和注意力（额中回）区域以及丘脑和楔前叶表现出更强的大脑激活。这些与疾病相关的差异主要见于女性受试者。
在情境威胁期间，IBS患者认知和情感大脑网络的参与度更高，这可能反映了IBS患者高估未来腹痛可能性和严重程度的倾向。
