This condition may occur in any case of acquired liver failure, including severe hepatitis.

Liver damage can lead to the buildup of ammonia and other toxic materials in the body. This happens when the liver doesn't work properly. It does not break down and eliminate these chemicals. The toxic materials can damage brain tissue.

Specific areas of the brain, such as the basal ganglia, are more likely to be injured from liver failure. The basal ganglia help control movement. This condition is the "non-Wilsonian" type. This means that the liver damage is not caused by copper deposits in the liver. This is a key feature of Wilson disease.

Symptoms may include:

• Difficulty walking
• Impaired intellectual function
• Jaundice
• Muscle spasm (myoclonus)
• Rigidity
• Shaking of arms, head (tremor)
• Twitching
• Uncontrolled body movements (chorea)
• Tremor of the hand when the wrist is extended (also called a flapping tremor or asterixis)
• Unsteady walking (ataxia)

Signs include:

• Coma
• Fluid in the abdomen that causes swelling (ascites)
• Gastrointestinal bleeding from enlarged veins in the food pipe (esophageal varices)

A nervous system (neurological) exam may show signs of:

• Dementia
• Involuntary movements
• Walking instability

Laboratory tests may show a high ammonia level in the bloodstream and abnormal liver function.

Other tests may include:

• MRI of the head
• EEG (may show general slowing of brain waves)
• CT scan of the head

Treatment helps reduce the toxic chemicals that build up from liver failure. It may include antibiotics (rifaximin) or a medicine such as lactulose, which lowers the level of ammonia in the blood.

A treatment called branched-chain amino acid therapy may also:

• Improve symptoms
• Reverse brain damage

There is no specific treatment for the neurologic syndrome, because it is caused by irreversible liver damage. A liver transplant may cure the liver disease. However, this operation may not reverse the symptoms of brain damage.

This is a long-term (chronic) condition that may lead to irreversible nervous system (neurological) symptoms.

The person may continue to get worse and die without a liver transplant. If a transplant is done early, the neurological syndrome may be reversible.

Complications include:

• Hepatic coma
• Severe brain damage

Contact your health care provider if you have any symptoms of liver disease.

It is not possible to prevent all forms of liver disease. However, alcoholic and viral hepatitis may be prevented.

To reduce your risk of getting alcoholic or viral hepatitis:

• Avoid risky behaviors, such as IV drug use or unprotected sex.
• Don't drink, or drink only in moderation.

Chronic acquired (Non-Wilsonian) hepatocerebral degeneration; Hepatic encephalopathy; Portosystemic encephalopathy

Garcia-Tsao G. Cirrhosis and its sequelae. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 144.

ul Haq I, Liebenow B, Okun MS. Clinical overview of movement disorders. In: Winn HR, ed. Youmans and Winn Neurological Surgery. 8th ed. Philadelphia, PA: Elsevier; 2023:chap 105.

Updated by: Michael M. Phillips, MD, Emeritus Professor of Medicine, The George Washington University School of Medicine, Washington, DC. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.