Hepatic Encephalopathy, Chronic Hepatic Encephalopathy (Portosystemic Encephalopathy), and Acute Liver Failure

Hepatic encephalopathy, also referred to as portosystemic encephalopathy (PSE), is a complex neuropsychiatric disorder resulting from chronic parenchymal liver disease or liver failure, often in conjunction with portosystemic shunts, either naturally occurring or surgically created. PSE is characterized by changes in personality, level of consciousness, motor function, and cognition. This chapter discusses the pathophysiology, pathogenesis, diagnosis, and treatment of hepatic encephalopathy as well as general considerations, clinical findings, complications, treatment, specific causes, and prognosis regarding acute liver failure (ALF). Tables describe the causes of cirrhosis of the liver, grades of hepatic encephalopathy, diagnostic criteria and precipitating factors for PSE, a comparison of PSE patients with spontaneous shunts and cirrhotic controls, factors that may result in overt PSE in patients with well-preserved liver function, considerations in the management of PSE, and causes of ALF. Figures illustrate the A-deletion and square, spiral, star, and signature tests; triphasic waves; and magnetic resonance images of a patient with PSE. Graphs show the relationship between rif