Hepatic encephalopathy shows very distinct clinical features combining cognitive dysfunction,
alterations of consciousness and motor symptoms indicating an alteration of the extrapyramidal and
cerebellar motor system and the pyramidal tract. Positron emission tomography studies of the cerebral
glucose utilisation in patients with liver cirrhosis and various grades of hepatic encephalopathy show
accordingly alterations in distinct brain areas – a decrease of the glucose utilisation especially in the frontal
cortex and anterior cingulated gyrus, and an increase in the hippocampus, basal ganglia and cerebellum.
These alterations in cerebral glucose utilisation correlate significantly with psychometric test results and
brain metabolite alterations as measured by magnetic resonance spectroscopy.
Keywords: Hepatic encephalopathy; [18F]fluoro-deoxy-D-glucose; Positron emission tomography; Magnetic
resonance spectroscopy; Attention system.