Regional differences in cerebral glucose metabolism in cirrhotic patients with subclinical hepatic encephalopathy using positron emission tomography.

Although it is recognized that abnormalities of glucose metabolism occur substantially throughout the brain in cirrhotic patients with subclinical hepatic encephalopathy (SHE), little attention has been paid to these abnormalities in situ due to technical difficulties. The aim of this study is to clarify the regional differences of cerebral glucose metabolism (CMRglu) in patients with or without SHE using positron emission tomography (PET). Fifteen patients with posthepatitic cirrhosis and 13 control subjects underwent PET imaging of the brain using 2-[18F]fluoro-2-deoxy-D-glucose. Neurological tests included the digit symbol and block design subtests from the Wechsler Adult Intelligence Scale. Auditory brain stem reaction and electroencephalogram were also used in diagnosis of SHE. Regions were defined as frontal, parietal, occipital, basal ganglia, and the white matter. The CMRglu value in the grey matter of SHE is lower than that of control, particularly in the frontal and temporal regions and basal ganglia (P<0.05, respectively). The CMRglu values in the grey matter of non-SHE and control are almost the same, excepting the basal ganglia. The CMRglu value in the basal ganglia of non-SHE is higher than that of control and SHE. The CMRglu value in the grey matter of SHE is depressed as compared to both non-SHE and control. These data suggest that the abnormalities of cerebral glucose metabolism may be a contributing factor in SHE.