Characterization of Cerebral Edema in Acute-on-Chronic Liver Failure

Abstract

The nature of cerebral edema in acute-on-chronic liver failure (ACLF) is not well studied. We aimed to characterize cerebral edema in ACLF using magnetization transfer ratio (MTR) and diffusion tensor imaging (DTI). Forty-six patients with cirrhosis and acute decompensation were included. Patients were divided into groups A (no cerebral failure, n=39) and B (cerebral failure, n=7). Group A was subdivided into no-ACLF (n=11), grade 1 (n=10), grade 2 (n=9) and grade 3 (n=9) ACLF as per CANONIC study. MRI brain and plasma TNF-alpha, IL-1beta and IL-6 were measured at baseline and 7-10 days after admission. Ten age- and sex-matched healthy controls were also included. Mean diffusivity (MD) values, an MRI marker of water content, progressively increased from controls to no-ACLF to ACLF grade 1, 2 and 3 in group A in frontal white matter (FWM) and basal ganglia (P<0.0001). MD values improved only in survivors on follow-up. MD values correlated with IL-6 levels at baseline. On multivariate analysis MELD score ≥28 and MD values (>8×10-9M2/s) in FWM were independent predictors of 90-day mortality. There was no significant difference in clinical and MRI parameters between group A and B. Cerebral edema increases with severity of ACLF. Correlation between MD values and IL-6 levels suggests pathogenic role of inflammation in cerebral edema. Patients with grade 3 ACLF have cerebral edema irrespective of presence of clinically evident cerebral failure. MELD score and cerebral edema have prognostic significance in ACLF.