[Hepatic encephalopathies].

The functional disturbances of the central nervous system in hepatic encephalopathy are due to several coexisting pathogenetic factors: Endogenous neurotoxins, imbalance of amino acids in blood plasma and alterations of the blood-brain barrier. These factors, in turn, effect alterations of neurotransmitters and their receptors. Therapeutic interventions are aimed at the inhibition of ammonia production by protein restriction, lactulose or antibiotics. A new therapeutic concept is the application of branched chain amino acids. Their effect is based on the stimulation of protein synthesis in muscle, enhanced urea synthesis in the liver and increased ammonia detoxification by glutamine synthesis in the brain.