Loss of brain function occurs when the liver is unable to remove toxins from the blood. This is called hepatic encephalopathy. This problem may occur suddenly or develop slowly over time.
An important job of the liver is to make toxic substances in the body harmless. These substances may be made by the body, such as ammonia. Or they may be substances that you take in, such as medicines.
When the liver is damaged, these "poisons" can build up in the bloodstream and affect the function of the nervous system. The result may be hepatic encephalopathy.
This problem can occur suddenly and you may become ill very quickly. Causes include:
- Hepatitis B infection (uncommon to occur this way)
- Blockage of blood supply to the liver
- Poisoning by different toxins or medicines
More often, the problem develops in people with chronic liver damage. Cirrhosis is the end result of chronic liver damage. Common causes of chronic liver disease in the United States are:
- Chronic hepatitis B or hepatitis C infection
- Alcohol abuse
- Autoimmune hepatitis
- Bile duct disorders
- Some medicines
- Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH)
Once you have liver damage, episodes of worsening brain function may be triggered by:
- Body is low on water or fluids
- Eating too much protein
- Low potassium or sodium levels
- Bleeding from the intestines, stomach, or esophagus
- Kidney problems
- Low oxygen levels in the body
- Shunt placement or complications
- Narcotic pain or sedative medicines
Disorders that can appear similar to hepatic encephalopathy include:
- Alcohol intoxication
- Alcohol withdrawal
- Bleeding under the skull
- Brain disorder caused by lack of Vitamin B1
In some cases, hepatic encephalopathy is a short-term problem that can be corrected. It may also occur as part of a chronic problem from liver disease that gets worse over time.
Symptoms may begin slowly and slowly get worse. They may also begin suddenly and be severe from the start.
Early symptoms may be mild and include:
- Breath with a musty or sweet odor
- Change in sleep patterns
- Changes in thinking
- Confusion that is mild
- Mental fogginess
- Personality or mood changes
- Poor concentration
- Poor judgment
- Worsening of handwriting or loss of other small hand movements
More severe symptoms may include:
- Abnormal movements or shaking of hands or arms
- Agitation, excitement, or seizures (occur rarely)
- Drowsiness or confusion
- Strange behavior or severe personality changes
- Slurred speech
- Slowed or sluggish movement
People with hepatic encephalopathy can become unconscious, unresponsive, and possibly enter a coma.
People are often not able to care for themselves because of these symptoms.
Exams and Tests
Signs of nervous system changes may include:
- Shaking of the hands ("flapping") when trying to hold arms in front of the body and lift the hands
- Problems with thinking and doing mental tasks
- Signs of liver disease, such as yellow skin and eyes (jaundice) and fluid collection in the abdomen (ascites)
- Musty odor to the breath and urine
Tests may include:
If changes in brain function are severe, a hospital stay may be needed.
- The first step is to identify and treat any factors that may have caused these changes. Bleeding in the digestive tract must be stopped. Infections, kidney failure, and changes in sodium and potassium levels need to be treated.
- Life support may be needed to help with breathing or blood flow. The brain may swell. This can be life threatening.
Medicines are given to help lower ammonia levels and improve brain function. You may need to take these medicines every day.
- Lactulose prevent bacteria in the intestines from creating ammonia. It also causes diarrhea and helps to remove blood from the intestines.
- Neomycin and rifaximin also reduce the amount of ammonia made in the intestines.
If the problem is very bad, you may need to cut down the protein in your diet. Talk to a dietitian about how to change your diet and avoid poor nutrition. People who are very ill may need intravenous or tube feedings.
Certain medicines should be avoided
- Any sedatives, tranquilizers, and any other medicines that are broken down by the liver.
- Medicines containing ammonium (including certain antacids)
Your health care provider may suggest other medicines and treatments. These may have varying results.
Acute hepatic encephalopathy may be treatable. Chronic forms of the disorder often continue to get worse and come back.
Both forms of the condition may result in irreversible coma and death. The majority of people who go into a coma will die. The chances of getting better vary from person to person.
When to Contact a Medical Professional
Call your health care provider if you or people around you notice any problems with your mental state or nervous system function. This is very important for people who already have a liver disorder. Hepatic encephalopathy can get worse quickly and become an emergency condition.
Treating liver problems may prevent hepatic encephalopathy. Avoiding heavy drinking and intravenous drug use can prevent many liver disorders.
Hepatic coma; Encephalopathy - hepatic; Hepatic encephalopathy
Garcia-Tsao G. Cirrhosis and its sequelae. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 153.
Leise MD, Poterucha JJ, Kamath PS, Kim WR. Management of hepatic encephalopathy in the hospital. Mayo Clin Proc. 2014;89(2):241-53. PMID 24411831 www.ncbi.nlm.nih.gov/pubmed/24411831.
Nevah MI, Fallon MB. Hepatic encephalopathy, hepatorenal syndrome, hepatopumonary syndrome, and systemic complications of liver disease. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger & Fordtran's Gastrointestinal and Liver Disease. 10th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 94.
- Abdominal tap
- Acute kidney failure
- Alcohol use disorder
- Alcohol withdrawal
- Alertness - decreased
- Ammonia poisoning
- Brain herniation
- Low blood sugar
- Protein in diet
- Subdural hematoma
- Transjugular intrahepatic portosystemic shunt (TIPS)
- Wernicke-Korsakoff syndrome
Review Date 8/14/2015
Updated by: Subodh K. Lal, MD, gastroenterologist at Gastrointestinal Specialists of Georgia, Austell, GA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.