Metabolic Encephalopathy
all information

Metabolic Encephalopathy

(Coma, Hepatic; Hepatic Coma; Hepatic Encephalopathy; Portal-Systemic Encephalopathy)

Pronounced: MET-a-bol-ik En-SEF-a-lo-PATH-ee

En Español (Spanish Version)


This condition is temporary or permanent damage to the brain. The most common cause is an illness or condition that affects the liver. Toxins build up in the bloodstream because the liver is not working normally.

Normal Oxygen Flow to Brain

oxygen brain lungs

An interruption of this flow can lead to metabolic encephalopathy.

© 2008 Nucleus Medical Art, Inc.


Metabolic encephalopathy is caused by:

Risk Factors

These factors increase your chance of developing metabolic encephalopathy:

Tell your doctor if you have any of these risk factors.

If you have liver problems, the risk of metabolic encephalopathy is increased by:

  • Low oxygen levels in the blood
  • Infections
  • Major surgery
  • Any serious illness that causes changes in the body’s chemical make-up or metabolism
  • Use of certain medicines, such as sedatives and narcotics
  • Bleeding within the intestines
  • Persistent vomiting or diarrhea that lowers blood potassium levels

The following toxic overdoses can also increase your risk of the condition:


Symptoms include:

  • Confusion or agitation
  • Changes in behavior and personality
  • Forgetfulness
  • Disorientation
  • Insomnia
  • Muscle stiffness or rigidity
  • Tremor (particularly a flapping tremor of the hands)
  • Difficulty speaking
  • Asterixis (rapid momentary loss of tone in the muscles)
  • Uncontrollable movements or seizures (rare)
  • Stupor or coma

These problems can develop quickly. They may resolve when the condition is reversed. However, prompt treatment is needed before a coma occurs.


Metabolic encephalopathy is very serious. It can quickly become an emergency. You will need to be hospitalized. Doctors will do an exam to assess your neurological condition.

The following tests may be done:

  • Blood tests—usually show high blood ammonia levels and other abnormalities related to the failing liver
  • Electroencephalogram (EEG)—may be used to determine how the brain has been affected
  • Imaging studies of the brain (CT scan or MRI)—may be done to evaluate other causes


Hospitalization and Emergency Care

In the hospital, the staff will treat the problems that caused metabolic encephalopathy. They will try to remove or neutralize toxins that have built up in the bloodstream. The goal is to reverse the underlying condition. But, brain injury can still occur. In some cases, brain injury is permanent.


Depending on the cause, certain medications may be used to neutralize toxins and treat the condition.

Dietary Restrictions

A low-protein diet is usually prescribed to help lower blood ammonia levels. (The body creates ammonia when it metabolizes and uses protein.) You may have other changes in your diet, such as salt and water restriction.

Tube feeding and life support may be required, especially in the case of coma.


If this condition is due to organ failure, you may need a transplant.


To help reduce your chance of getting this condition, take the following steps:

  • Get early treatment for liver problems. If you have liver problems and any of the above symptoms, call your doctor right away.
  • If you have a disease (such as cirrhosis), see your doctor regularly.
  • Avoid overdosing. Avoid being exposed to poisons or toxins.


National Digestive Diseases Information Clearinghouse

National Institute of Neurological Disorders and Stroke


Canadian Liver Foundation

Health Canada


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Hepatic encephalopathy. EBSCO DynaMed website. Available at: Updated April 2008. Accessed July 28, 2008.

Juretschke L. Kernicterus: still a concern. Neonatal Netw. 2005;24:7-9.

Lizardi-Cervera J, Almeda P, Guevara L, et al. Hepatic encephalopathy: a review. Ann Hepatol. 2003;2:122-130. Review.

Siegal GJ, Agranoff BW, Albers RW, Uhler MD. Metabolic encephalopathies. In: Basic Neurochemistry: Molecular, Cellular, and Medical Aspects. 6th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 1999.

Toftengi F, Larsen F. Management of patients with fulminant hepatic failure and brain edema. Metab Brain Dis. 2004;19:207-214.

Last reviewed May 2008 by Rimas Lukas, MD

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.

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