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Background In Crohn's disease (CD) patients, stress is believed to influence symptoms generation. Stress may act via central nervous system pathways to affect visceral sensitivity and motility thus exacerbating gastrointestinal symptoms. The neural substrate underpinning these mechanisms needs to be investigated in CD. We conducted an explorative functional magnetic resonance imaging (fMRI) study in order to investigate potential differences in the brain stress response in CD patients compared to controls. Methods 17 CD patients and 17 healthy controls underwent a fMRI scan while performing a stressful task consisting in a Stroop color-word interference task designed to induce mental stress in the fMRI environment. Key Results Compared to controls, in CD patients the stress task elicited greater blood oxygen level dependent (BOLD) signals in the midcingulate cortex (MCC). Conclusions & Inferences The MCC integrate “high” emotional processes with afferent sensory information ascending from the gut. In light of these integrative functions, the stress-evoked MCC hyperactivity in CD patients might represent a plausible neural substrate for the association between stress and symptomatic disease. The MCC dysfunction might be involved in mechanisms of central disinhibition of nociceptive inputs leading to amplify the visceral sensitivity. Finally, the stress-evoked MCC hyperactivity might affect the regulation of intestinal motility resulting in exacerbation of disease symptoms and the autonomic and neuroendocrine regulation of inflammation resulting in enhanced inflammatory activity.

Ulcerative colitis (UC) is associated with psychological stress and poor emotional functioning. The neural emotional processing involves the complex integration of several cortical and subcortical brain structures. The amygdala plays a fundamental role in the neural processing of emotional stimuli and is a core structure of the brain-gut axis (BGA) that represents the anatomo-functional substrate for the bidirectional influences between emotions and gastrointestinal functions. The aim of this study was to investigate the brain emotional processing in UC patients compared to healthy people. METHODS: Ten UC patients in remission and 10 matched healthy controls underwent a functional magnetic resonance imaging (fMRI) scan while performing a task involving emotional visual stimuli. A set of negative, positive, and neutral pictures were used to study brain-related emotional responses. RESULTS: A significantly reduced blood oxygen level-dependent (BOLD) signal in UC patients relative to controls was found in the amygdala, thalamic regions, and cerebellar areas (P < 0.05 corrected for multiple comparisons). The group-related differences were detected in the brain activity in response to positive emotional stimuli. CONCLUSIONS: UC is associated with an emotional dysfunction characterized by decreased sensitivity to emotions with a positive content. The previous intestinal inflammatory activity in UC patients might have contributed to determine the functional changes of the amygdala that we found. On the other hand, the dysfunction of the amygdala may influence the course of the disease.

Background Crohn’s disease (CD) is a chronic intestinal disorder characterized by overproduction of inflammatory cytokines and recurrent abdominal pain. Recently, brain morphological abnormalities in the pain matrix were found in patients with chronic pain disorders including irritable bowel syndrome. To investigate potential structural brain changes associated with CD, we used magnetic resonance imaging (MRI). Furthermore, we tested whether in patients gray matter (GM) volumes correlated with disease duration. Methods Eighteen CD patients in remission and 18 healthy controls underwent structural MRI. Voxel-based morphometry (VBM) is a fully automated technique allowing identification of regional differences in the amount of GM enabling an objective analysis of the whole brain between groups of subjects. VBM was used for comparisons and correlation analysis. Key Results With respect to controls, CD patients exhibited decreased GM volumes in portion of the frontal cortex and in the anterior midcingulate cortex. Disease duration was negatively correlated with GM volumes of several brain regions including neocortical and limbic areas. Conclusions & Inferences Crohn’s disease is associated with brain morphological changes in cortical and subcortical structures involved in nociception, emotional, and cognitive processes. Our findings provide new insight into the brain involvement in chronic inflammatory bowel disorders

In patients with Crohn's disease (CD) stress is believed to increase the incidence of disease relapse. The brain processes stressful stimuli and triggers the stress-evoked responses. Habituation to stress is an adaptive process that allows minimizing these responses. We hypothesized inadequate habituation to stress in CD patients. The aim of this study was to compare the neural habituation between CD patients and controls. Twenty CD patients and eighteen controls underwent a functional magnetic resonance imaging while performing two repeated runs of a stress-evoking task. The task elicited different neural activity between the groups across runs in (1) amygdala, hippocampus, (2) insula, putamen (3) cerebellar regions, suggesting altered habituation to stress in patients. These structures regulate the neuroendocrine and autonomic stress-evoked responses that control the proinflammatory responses. The inadequate habituation to stress that we found in patients could play a role in the relationship between stress and inflammatory exacerbations in CD.