Long-Term Evaluation of Cognitive Function and Cerebral Metabolism in Liver Transplanted Patients

Introduction. Patients with liver cirrhosis without overt hepatic encephalopathy (OHE) show alterations of cognitive function and metabolism which seem to not be fully reversible after liver transplantation (OLT), but the long-term outcomes have not be studied. Methods. Fourteen cirrhotic subjects including alcoholic (n = 4), viral (n = 4), mixed (n = 5), and cholestatic (n = 2) without OHE were evaluated for OLT as well as 8 age-matched normal controls. All subjects underwent cerebral positron emission tomography (PET) with 18F-fluorodeoxyglucose to quantify cerebral glucose metabolism and neuropsychological evaluation to test memory, intelligence, and cerebral frontal functions. Transplanted patients underwent repeat evaluations at 1 and 10 years after liver transplantation. Results. Compared with the controls patients with liver cirrhosis showed significantly reduced cerebral glucose metabolism in all cerebral cortical and subcortical regions. This observation correlated with the presence of alterations in neuropsychological tests evaluating memory, frontal tasks, and visuospatial memory. Among 12 patients who were transplanted, 10 underwent repeat neuropsychological evaluation at 1 year; in addition 5 underwent PET). At 10 years the 7 living patients had repeat neuropsychological evaluation. One year after OLT, transplanted patients showed significant amelioration of cerebral glucose metabolism in all cerebral regions with significant improvements in neuropsychological tests, despite 20% of patients showing residual defects in frontal tasks. The cognitive function did not further improve at 10 years after OLT. Conclusion. Patients with liver cirrhosis show altered cerebral function and metabolism that revert after successful liver transplantation, but with residual mild deficits in cerebral frontal functions, which seem to not improve in the long term.