The correlation between brain structure, function, and cognitive changes in patients with active-stage ulcerative colitis

Background: Patients with active ulcerative colitis (UC) frequently exhibit emotional disturbances and cognitive deficits. However, the neurobiological basis of these manifestations remains poorly understood. This study investigates neurostructural and functional alterations in UC patients using multimodal MRI to identify potential neural correlates. Methods: We enrolled 45 active-stage UC patients and 48 healthy controls, all of whom underwent structural MRI, resting-state functional MRI (rs-fMRI), neurocognitive testing, and clinical assessments. Regional neural activity was evaluated using fractional amplitude of low-frequency fluctuations (fALFF), while gray matter volume (GMV) was analyzed to assess structural differences. Brain regions showing significant abnormalities were further examined for correlations with cognitive performance and clinical scale results. Results: Compared to the healthy control group, the UC patient group exhibited higher scores in PSQI, PSS, SAS, and SDS. Furthermore, the UC patient group displayed varying degrees of impairment in attention, working memory, and executive function. The GMV of the bilateral thalamus in UC patients decreased, while the fALFF values in bilateral posterior cingulate gyrus (PCG) and left lingual gyrus increased. Conversely, the fALFF values in multiple brain regions, including bilateral frontal lobes, the right temporal lobe, and the right inferior parietal lobule, were decreased. Multiple brain regions with reduced activity in the bilateral frontal lobes are closely related to emotions and executive control, while the increased activity in the bilateral PCG is strongly correlated with stress and anxiety. The reduction GMV in bilateral thalamic is associated with working memory and attention. Conclusion: Cognitive impairment and emotional abnormalities in UC are associated with the functional activity and structure of multiple brain regions, particularly in the bilateral frontal lobes, PCG and thalamus. These findings provide potential neuroimaging evidence for the activation of the gut-brain axis due to chronic inflammation, and that certain brain regions may be considered as key targets for predicting cognitive impairment for UC patients.