Hepatic coma: acute hepatic necrosis; fulminant; delirium, convulsions, coma, decerebrate rigidity. Often fatal. Serum ammonia high.

Hepatic encephalopathy: usually with chronic liver disease. Failure of liver to detoxify blood from gastrointestinal system. Episodic ataxia, tremor, dysarthria, sensorial clouding, asterixis. May have progressive syndrome of dementia, ataxia, dysarthria, tremor, choreoathetosis (acquired chronic hepatocerebral degeneration). Convulsions rare in hepatic encephalopathy (vs. uremic encephalopathy).

Laboratory data: high serum ammonia, CSF glutamine content high.

Pathophysiology: increased sensitivity to inhibitory neurotransmitters such as gamma amino butyric acid (GABA) may underlie encephalopathy. Ammonia likely not responsible.