Treatment of hepatic encephalopathy by infusion of a modified amino acid solution: results of a controlled study in 47 cirrhotic patients

The mechanism of hepatic encephalopathy (HE) is still unknown. A characteristic amino acid pattern in HE has been described: an increased level of plasma free tryptophan, a fall in plasma branched chain amino acids (BCAA) valine, leucine and isoleucine and a rise in plasma aromatic amino acids (AAA) phenylalanine and tyrosine.1 The brain uptake of AAA would increase; the ensuing depletion of brain dopamine and norepinephrine and increase of brain octopamine, which is considered as a false neurotransmitter, would result in perturbation of cerebral neurotransmission.2