Improvement of regional cerebral blood flow after treatment with branched-chain amino acid solutions in patients with cirrhosis.

Objective: The administration of solutions rich in branched-chain amino acids leads to mental recovery from acute hepatic encephalopathy in patients with liver cirrhosis. However, the mechanism of action of branched-chain amino acids remains unclear. The purpose of this study was to evaluate the effect of intravenous infusion of branched-chain amino acids on brain perfusion in patients with liver cirrhosis.

Methods: Single photon emission computed tomography scans were performed in 14 patients with liver cirrhosis before and after the administration of branched-chain amino acids in a single-day split-dose protocol. The per cent change in regional brain perfusion was calculated in high frontal, parietal, temporal, occipital lobes and cerebellum. Thereafter, statistical parametric mapping was performed to identify brain regions with abnormal cerebral perfusion.

Results: Intravenous infusion of solutions enriched with branched-chain amino acids induced a 13-20% increase in regional cerebral blood flow. Cirrhotic patients had regions of significant hypoperfusion, as determined by statistical parametric mapping, in the left superior parietal and posterior cingulate as compared to the control group. This hypoperfusion of parietal and cingulate regions was not detected after treatment with solutions of branched-chain amino acids.

Conclusions: The results of the present study suggest that administration of solutions enriched with branched-chain amino acids improves cerebral perfusion in patients with cirrhosis.