MR and 1H MR spectroscopy of the brain in patients with liver cirrhosis and early stages of hepatic encephalopathy.

BACKGROUND/AIMS: Hepatic encephalopathy is a serious problem in patients with liver cirrhosis and precise pathophysiological mechanisms responsible for encephalopathy are not fully understood. Magnetic resonance imaging and magnetic resonance spectroscopy can be used to detect specific morphological and metabolic abnormalities in the brain even in patients with early stages of hepatic encephalopathy.
METHODOLOGY: Twenty patients with liver cirrhosis and 14 patients with grade I-II hepatic encephalopathy were studied with magnetic resonance and proton magnetic resonance spectroscopy. Localized magnetic resonance spectra were acquired in the parietal gray/white matter regions and basal ganglia. Control group consisted of 20 healthy volunteers.
RESULTS: Frequency and degree of brain atrophy and bilateral signal hyperintensities in globus pallidus were similar in groups with liver cirrhosis and with encephalopathy. Decreased myoinositol, choline and increased glutamine levels were noted in both groups whereas N-acetylaspartate levels were unchanged. The statistically significant differences between cirrhotic and encephalopathic groups were observed only in myoinositol/creatine ratio in basal ganglia. There were no significant differences in metabolic concentrations between parietal and basal ganglia regions.
CONCLUSIONS: Metabolic brain alterations occur earlier than clinical evidence of hepatic encephalopathy but there is no correlation between presence of symptoms encephalopathy and magnetic resonance and magnetic resonance spectroscopy findings.