The word encephalopathy describes any disturbance of the brain's functioning that leads to problems like confusion and memory loss.
Encephalopathy is not a single disease; it can have a wide range of underlying causes.
Types of encephalopathy
There are many types of encephalopathy, including:
- Hepatic encephalopathy - a problem with the liver causes a build-up of toxic substances that the liver normally removes. These toxic substances then disturb the normal functioning of the brain. Hepatic encephalopathy can be caused by a chronic liver condition, an infection, overdose of prescription medications or bleeding in the digestive tract.
- Chronic traumatic encephalopathy (CTE) - this is probably caused by repeated blows to the head and concussions. It is associated with contact sports such as boxing and football.
- Hypoxic-ischaemic encephalopathy - in this case, lack of oxygen to the brain leads to abnormal brain function. This can be caused by heavy bleeding, near-drowning or near-suffocation.
- Hashimoto’s encephalopathy - this type of encephalopathy is thought to be caused by a person’s immune system attacking the brain.
It can also be caused by:
- infection from bacteria or viruses
- problems with metabolism
- brain tumours
- exposure to toxic substances such as paints, solvents or radiation.
Some people have acute encephalopathy, which comes on fairly quickly and can go away. Others have chronic encephalopathy, which tends to develop slowly and not go away. Some encephalopathies cause permanent damage to the brain, while others do not. Some can be fatal.
The symptoms of encephalopathy vary from person to person.
The most common symptom of encephalopathy is a change in mental state, with problems such as:
- loss of memory
- reduced ability to think clearly or concentrate
- changes in personality such as those involving irritability, aggression, impulsive behaviour or having suicidal thoughts.
Some people might also have:
- involuntary muscle twitching
- difficulty speaking
- unusual eye movements
- muscle weakness
- difficulty swallowing.
Diagnosing an encephalopathy
If your doctor believes you might have an encephalopathy, they will try to discover the underlying cause. This might be an infection, or a particular drug or medication you are taking.
To work out whether you have an encephalopathy, and what type it might be, your doctor may use a combination of:
- talking to you and examining you
- doing blood tests
- sampling your spinal fluid via a lumbar puncture
- brain scans, such as computed tomography (CT) or magnetic resonance imaging (MRI) scans
- electroencephalography (EEG; a measure of electrical activity in your brain)
- testing your mental state and ability.
Treating an encephalopathy
People with an acute encephalopathy need to be treated in hospital. Treatment focuses on improving symptoms and can include:
- medication to, for example, reduce seizures or reduce ammonia levels in people with a hepatic encephalopathy
- making dietary changes or using nutritional supplements.
In some severe cases of encephalopathy related to liver or kidney function, dialysis or organ replacement might be needed.
Hepatic encephalopathy is often reversible with treatment. However, people with a chronic liver disorder are more likely to have recurring episodes of encephalopathy and need ongoing treatment.
When to seek help
If you, or someone you know, notices any new problems that might be symptoms of encephalopathy, call your doctor or go to the nearest emergency department. This is especially important if you have already had a liver problem because hepatic encephalopathy can become an emergency.
Last reviewed: July 2017