Differential Brain Structural and Functional Patterns in Crohn's Disease Patients are Associated with Different Disease Stages

Background: Crohn's disease (CD) is an inflammatory, chronic disorder that alternates between a quiescent phase and inflammatory flare-ups. Research has begun to elucidate the impact of CD in modulating brain structure and function. The previous neuroimaging studies mainly involved CD patients in remission (CD-R); therefore, little is known about how inflammation influences brain-related features in different stages of the disease. We carried out a magnetic resonance imaging (MRI) study to explore whether the different levels of disease activity may differentially affect brain structure and function. Methods: Fourteen CD-R patients, 19 patients with mild to moderate inflammatory activity (CD-A), and 18 healthy controls (HCs) underwent an MRI scan including structural and functional sequences. Results: Between-group comparisons showed morphological and functional brain differences distinctively associated with the stage of disease activity. The CD-A patients had reduced gray matter within the posterior cingulate cortex (PCC) relative to CD-R patients. Analysis on resting fMRI data showed the following patterns: (1) increased connectivity within the left fronto-parietal network (in the superior parietal lobe) in CD-R patients relative to CD-A patients; (2) decreased connectivity in the motor network (in parietal and motor areas) in the CD-A group relative to the HC group; (3) reduced connectivity in the motor network and (4) in the language network (in parietal areas and in the PCC) in CD-R patients relative to HC. Conclusions: The present findings represent a further step towards understanding brain morphological and functional changes in the active vs remission stages of CD patients.