The defect in learning of response inhibition at the Inhibitory Control Test has been proposed as a tool to detect the persistence of cognitive defects after the resolution of overt HE (OHE). In order to verify this observation, we test the ability of learning the Psychometric Hepatic Encephalopathy Score (PHES) in 106 cirrhotics who agreed to be examined twice within 3 days.

Twenty-seven patients had previous OHE. Of the remaining 79 patients without prior OHE, 34 were affected by minimal-HE and 45 were normal. In patients without previous OHE, PHES significantly improved at the second examination and this learning effect was present in the patients with or without minimal-HE.

On the contrary, the learning ability was lost in patients with previous OHE. Even in the 8 patients with history of HE and normal PHES at first examination, the repetition of the tests showed the lack of learning capacity.

Our data suggest that HE is not a fully reversible condition. The residual cognitive impairment should be searched by specific tests based on the patients' learning capacity.