Background: Therapeutic trials suggest that lactulose is an effective treatment of acute and chronic encephalopathy in cirrhotic patients.

Aim and Methods: As it is likely that portal-systemic shunting and hepatocellular dysfunction are associated with some degree of neurological dysfunction, 14 patients with cirrhosis and documented portal-systemic shunting, but without detectable encephalopathy, were randomized to treatment with either lactulose 20 g t.d.s., or lactose 20 g t.d.s. as placebo, for a 15-day period. Monitoring included manually administered and computer-based psychometric testing, the results of which were correlated with a battery of biochemical and functional parameters.

Results: There was no correlation between biochemical or functional parameters and psychometric testing. There was a close correlation between the time required to complete the number connection test and both the number of errors and the duration of errors at sinusoid testing. Lactulose therapy resulted in a significant improvement, assessed by the number connection test and the race track test.

Conclusion: Our data suggest that lactulose therapy might improve subclinical hepatic encephalopathy in patients with cirrhosis and portal-systemic shunting.