Shared and distinct spontaneous brain activity pattern in crohn's disease and ulcerative colitis: evidence from...

Crohn's disease (CD) and ulcerative colitis (UC), the two major forms of inflammatory bowel disease (IBD), are associated with emotional disturbances, but their shared and distinct neurobiological substrates remain unclear. This neuroimaging study aimed to characterize shared and distinct patterns of spontaneous neural activity in CD and UC patients using resting-state functional MRI (rs-fMRI).

Using cortical surface-based analysis of rs-fMRI data, we compared intrinsic neural activity, measured by amplitude of low-frequency fluctuations (ALFF) and regional homogeneity (ReHo), in 248 patients with IBD (180 CD, 68 UC) and 190 healthy controls (HC), controlling for gray matter volume. Demographic, clinical, and neuropsychological data were collected. Group comparisons and correlation analyses were performed.

Compared to HC, both CD and UC patients exhibited reduced ALFF and ReHo in bilateral somatosensory and motor cortices. Disease-specific patterns emerged: CD showed lower ReHo in lateral temporal cortices, while UC demonstrated higher ReHo in medial temporal and superior parietal regions. Correlation analyses revealed that in CD, motor cortex activity was linked to systemic symptoms and emotional function, whereas in UC, it correlated primarily with somatization.

This study identifies a common neural signature of sensory-motor dysfunction in IBD, alongside subtype-specific cortical patterns. By directly comparing CD and UC with a multimodal, surface-based approach and controlling for structural differences, our findings provide novel evidence for distinct brain-gut pathophysiology, highlighting neuroimaging as a potential tool for mechanistic insight and patient stratification.