Abnormal brain structure implicated in patients with functional dyspepsia

Recent studies suggest dysfunctional brain-gut interactions are involved in the pathophysiology of functional dyspepsia (FD). However, limited studies have investigated brain structural abnormalities in FD patients. This study aimed to identify potential differences in both cortical thickness and subcortical volume in FD patients compared to healthy controls (HCs) and to explore relationships of structural abnormalities with clinical symptoms. Sixty-nine patients and forty-nine HCs underwent 3T structural magnetic resonance imaging scans. Cortical thickness and subcortical volume were compared between the groups across the cortical and subcortical regions, respectively. Regression analysis was then performed to examine relationships between the structure alternations and clinical symptoms in FD patients. Our results showed that FD patients had decreased cortical thickness compared to HCs in the distributed brain regions including the dorsolateral prefrontal cortex (dlPFC), ventrolateral prefrontal cortex (vlPFC), medial prefrontal cortex (mPFC), anterior/posterior cingulate cortex (ACC/PCC), insula, superior parietal cortex (SPC), supramarginal gyrus and lingual gyrus. Significantly negative correlations were observed between the Nepean Dyspepsia Index (NDI) and cortical thickness in the mPFC, second somatosensory cortex (SII), ACC and parahippocampus (paraHIPP). And significantly negative correlations were found between disease duration and the cortical thickness in the vlPFC, first somatosensory cortex (SI) and insula in FD patients. These findings suggest that FD patients have structural abnormalities in brain regions involved in sensory perception, sensorimotor integration, pain modulation, affective and cognitive controls. The relationships between the brain structural changes and clinical symptoms indicate that the alternations may be a consequence of living with FD.