325 Abnormal Regional Homogeneity in Patients With Crohn's Disease and Its Relationship With Abdominal Pain

Abstract

Background & aims: Increasing evidence indicates abnormal pain processing in the central nervous system in patients with Crohn's disease (CD). The purpose of this study was to understand changes in resting-state brain activity in CD patients in remission and its relationship with abdominal pain. Methods: Twenty-five CD patients with abdominal pain, 24 CD patients without abdominal pain, and 33 healthy control subjects were scanned using a 3.0 T functional magnetic resonance imaging (fMRI) scanner. Regional Homogeneity (ReHo) was used to assess resting-state brain activity among the three groups. Daily pain scores were collected 1 week before fMRI scanning. Results: Patients with abdominal pain exhibited lower ReHo values in the insula, middle cingulate cortex (MCC), supplementary motor area, and higher ReHo value in the temporal pole, whereas patients without abdominal pain exhibited lower ReHo value in the hippocampal/parahippocampal cortex and higher ReHo value in the dorsomedial prefrontal cortex (dmPFC) (all P<0.05). The ReHo values of the insula and MCC were significantly negatively correlated with abdominal pain scores (r=0.53, P=0.008, and r=-0.61, P=0.002, respectively) (Figure 1). Conclusion: We suggest that there exist different changes in resting-state brain activity between CD patients in remission with and without abdominal pain. The negative correlations between pain severity and ReHo values of the insula and MCC in the painful CD patients suggest the involvement of these brain regions in visceral pain processing.