Brain Dysfunction Primarily Related to Previous Overt Hepatic Encephalopathy Compared with Minimal Hepatic Encephalopathy: Resting-State Functional MR Imaging Demonstration

Purpose: To investigate whether resting-state brain functional connectivity (FC) differed among cirrhotic patients without overt hepatic encephalopathy (HE) (OHE), those who currently had minimal HE (MHE), or those who had recovered from previous OHE and to investigate whether previous bouts of OHE rather than current MHE predominantly contributed to brain dysfunction in patients without current OHE. Materials and Methods: This study was approved by the institutional ethics committee, and informed consent was obtained. Resting-state functional magnetic resonance (MR) data were compared between healthy controls and the following groups of cirrhotic patients: (a) patients without MHE and without previous OHE, (b) patients with current MHE and without previous OHE, and (c) patients with previous OHE. Independent component analysis was applied to identify the best-fit component for the default-mode network (DMN). One-way analysis of variance was performed to detect different FC among groups. Pearson correlation analyses were conducted to determine the relationships between FC and neurocognitive performance. Results: Two important regions within the DMN, including the precuneus and posterior cingulate cortex and left medial frontal gyrus, showed significantly different FC among the four groups. A trend of gradually reduced FC in two regions was observed from controls, to patients without HE, and to patients with current MHE, while patients with previous OHE showed remarkably reduced FC in these two regions. Significant correlations were found between FC and neurocognitive performance in cirrhotic patients. Conclusion: The reduced resting-state FC within DMN was associated with neurocognitive impairments in MHE and after clinical resolution of OHE. Previous OHE rather than current MHE might be primarily related to brain dysfunction in patients with latent OHE. (C)RSNA, 2012 Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12120026/-/DC1