Exploring brain dysfunction in IBD: A study of EEG-fMRI source imaging based on empirical mode diagram decomposition

Patients with inflammatory bowel disease (IBD) often suffer from mood disorders and cognitive decline, which has prompted research into abnormalities in emotional brain regions and their functional analysis. However, most IBD studies only focus on single-modality neuroimaging technologies. Due to a limited spatiotemporal resolution, it is unfeasible to fully explore deep brain source activities and accurately evaluate the brain functional connectivity. Therefore, we propose an electroencephalography (EEG)-functional magnetic resonance imaging (fMRI)source imaging method based on an empirical mode diagram decomposition (EMDD) and performed a synchronous EEG-fMRI source imaging analysis on 21 IBD patients and 11 healthy subjects. The high-frequency spatial components of the fMRI were extracted through EMDD as prior constraints and compared with the EEG source imaging based on the entire fMRI spatial prior. Then, the cortical source time series were reconstructed according to the Desikan-Killiany atlas for an effective connectivity analysis. The results showed that the EEG-fMRI source imaging based on EMDD had a better performance, with the average log model evidence increased by 29.60% and the average explained variance increased by 19.12%. There were significant differences in the activation intensity of a series of abnormal brain regions between IBD patients and healthy controls, some of which were newly discovered: the uncus, claustrum, lentiform nucleus, and lingual gyrus. Moreover, the findings from the effective connectivity analysis of cortical source signals revealed that IBD patients had information flow loss in the frontal lobes, central areas, left parietal lobe, and right temporal lobe, and the information flow intensity of the right lingual gyrus was enhanced.