Disrupted topological organization of brain structural network associated with prior overt hepatic encephalopathy in cirrhotic patients.

OBJECTIVES

To investigate structural brain connectome alterations in cirrhotic patients with prior overt hepatic encephalopathy (OHE).

METHODS

Seventeen cirrhotic patients with prior OHE (prior-OHE), 18 cirrhotic patients without prior OHE (non-prior-OHE) and 18 healthy controls (HC) underwent diffusion tensor imaging. Neurocognitive functioning was assessed with Psychometric Hepatic Encephalopathy Score (PHES). Using a probabilistic fibre tracking approach, we depicted the whole-brain structural network as a connectivity matrix of 90 regions (derived from the Automated Anatomic Labeling atlas). Graph theory-based analyses were performed to analyse topological properties of the brain network.

RESULTS

The analysis of variance showed significant group effects on several topological properties, including network strength, global efficiency and local efficiency. A progressive decrease trend for these metrics was found from non-prior-OHE to prior-OHE, compared with HC. Among the three groups, the regions with altered nodal efficiency were mainly distributed in the frontal and occipital cortices, paralimbic system and subcortical regions. The topological metrics, such as network strength and global efficiency, were correlated with PHES among cirrhotic patients.

CONCLUSIONS

The cirrhotic patients developed structural brain connectome alterations; this is aggravated by prior OHE episode. Disrupted topological organization of the brain structural network may account for cognitive impairments related to prior OHE.

KEY POINTS

• Altered structural brain connectome is found in cirrhotic patients. • Structural brain connectome alterations could be aggravated by prior-OHE episode. • Altered structural brain connectome may account for cognitive impairments associated with prior OHE.