Hepatic encephalopathy is one of the most frequent terminal episodes of primary liver disease. It was already known at the time of Hippocrates, and it was well described by Johanne Baptista Margagni, teacher at the Padua Medical School, in the 18th century. Hepatic encephalopathy is a neuropsychiatric syndrome seen in the pres ence of hepatic functional impairment secondary to acute liver failure or chronic parenchymal liver disease with or without spontaneous or surgi cally induced portalsystemic shunting of portal blood. The neuropsychiatric symptoms of liver failure are varied and range from subtle alterations, including mild personality change and disturbance in sleep rhythm, to confusion, drowsiness, stupor, and finally deep coma. In acute liver failure the progression of events may be extremely rapid, taking place in only a few hours. In chronic encephalopathy, in contrast, consciousness may be slowly altered over months, and may occasionally present as progressive and irre versible neurological symptomatology with dementia, parkinsonism, or other extrapyramidal signs suggesting involvement of the cerebellum or basal ganglia (170). Most often in the chronic situation, however, episodes of mental impairment are episodic, the result of defined stresses, and recov ery to the premorbid state is the rule. Other symptoms of hepatic encephalopathy are not specific for liver disease. Asterixis (flapping tremor of the extremities) is probably the most characteristic neurological sign of hepatic encephalopathy, is more common