Brain Functional Changes in Patients with Ulcerative Colitis: A Functional Magnetic Resonance Imaging Study on Emotional Processing

Background: 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.