Normalization of abnormal electroencephalograms in beagles with portacaval anastomosis by infusion of solutions rich in branched-chain amino acids.

The effects of intravenous infusions of amino acid solutions on the electroencephalograms (EEG) and biochemical indices of 12 beagle dogs with a portacaval anastomosis (PCA) were studied in unanesthetized and unrestrained conditions. EEGs were recorded everyday from 2 days after the operation. When the EEGs showed predominant delta and theta frequency bands (slow-wave), solutions of amino acids were infused intravenously at 5 ml/kg/hr for an hour. Blood was withdrawn immediately before and after the infusion to determine plasma amino acids and ammonia. Infusion of amino acid solutions enriched in branched-chain amino acids (BCAA) with restricted aromatic amino acids (AAA) normalized the predominantly slow-wave EEGs. These solutions reduced the increased plasma AAA and ammonia concentrations and increased the lowered plasma BCAA concentrations. The abnormal EEGs were not improved by infusion with a balanced and AAA-enriched amino acid solution for nutritional support of surgical patients and became worse on infusion of AAA solution. Significant correlations were found between percent changes in the incidence of slow-waves and plasma AAA concentrations. These results suggest that infusion of solution with low AAA and high BCAA concentrations may be suitable for treatment of cirrhotic patients with abnormal EEG or with hepatic encephalopathy.