Simple tools for complex syndromes: a three-level difficulty test for hepatic encephalopathy.

BACKGROUND: Despite the impact of hepatic encephalopathy on quality of life and prognosis, easily administered tests for its diagnosis are still lacking. AIM: To assess the usefulness of the Scan package, a three-level-difficulty computerised reaction time test, to diagnose varying degrees of hepatic encephalopathy.
METHODS: Sixty-one cirrhotic patients underwent clinical evaluation, paper-and-pencil psychometry and the Scan package; 32 healthy controls served as reference.
RESULTS: Twenty-nine patients were classified as unimpaired, 15 as having minimal and 17 as having overt hepatic encephalopathy. All healthy controls were able to complete the Scan package; in contrast, the number of patients who were able to complete three/two/one part decreased in parallel with the degree of encephalopathy (χ(2)=17, p=0.01). Reaction times in all three parts increased significantly with the severity of encephalopathy. However, the profile of increase was different [group: F(3,77)=26, p<0.0001; test: F(2,154)=277, p<0.0001; group×test: F(6,154)=7, p<0.0001], with different parts being more/less sensitive to varying degrees of encephalopathy.
CONCLUSIONS: The Scan package seems useful for the diagnosis of hepatic encephalopathy and covers a considerable portion of its spectrum of severity.