1Department of Neurology, Hannover Medical School, Hannover, Germany.
Minimal hepatic encephalopathy (mHE) is diagnosed in patients with severe liver disease but no clinical symptoms of encephalopathy if either neuropsychological or neurophysiological tests indicate cerebral dysfunction and other possible causes of brain dysfunction have been excluded. mHE is characterized by deficits in attention, visuospatial orientation, visuoconstructive abilities and motor function. Accordingly, mHE can be expected to interfere with a subject's working ability, especially in those occupations that require handiwork, and driving ability. Indeed, about 60% of blue-collar workers with mHE have been shown to be assessed as unfit for work compared to only 20% of white-collar workers, and about 50% of patients with mHE have been judged unfit to drive a car in several studies. mHE interferes with a patient's quality of life and is associated with an increased risk of developing overt HE as well as increased mortality. Whether mHE is of importance for cognitive function after liver transplantation has still to be clarified.