Health Library

Acute Disseminated Encephalomyelitis (ADEM)

The body’s immune system protects it from foreign objects. With an autoimmune disorder, it doesn’t recognize its own healthy tissue and attacks it.

ADEM is not present at birth. It develops as the immune system matures. It often appears during childhood years, with most patients developing symptoms in early childhood. Often (three of every four patients), ADEM is a post-infectious process, meaning that families can identify an illness that happened one to three weeks before ADEM symptoms started.

Treatment is important to maintain the best possible health and function. Typically, children who have ADEM have a good recovery and recurrence is uncommon. Sometimes lasting symptoms such as seizures, difficulty with movements, or behavioral changes can occur.

What Causes ADEM?

There are several causes of ADEM. Around 75% of patients with ADEM had an upper respiratory infection or fever within the past month. Around half of cases have an underlying antibody such as Myelin Oligodendrocyte (MOG) or anti-NMDA receptor that may further guide treatment.

What Are the Symptoms of ADEM?

Symptoms can be different from child to child. Not all children will have all the symptoms listed.

Common symptoms for ADEM in children include:

• Irritability
• Confusion
• Increased sleepiness
• Ataxia (imbalance)
• Seizures
• Optic neuritis (vision loss, pain with eye movement)
• Speech problems
• Recurrent abnormal movements
• Weakness
• Bowel/bladder changes (changes peeing and pooping)
• Difficulty with breathing

How is ADEM Diagnosed?

A neurologist is a doctor who specializes in conditions that affect the brain and nerves. The doctor will ask about symptoms and do a neurologic exam. The doctor tests vision, hearing, sensation, strength and swallowing. Coordination, balance and reflexes also are tested.

To confirm that a child has ADEM, doctors use additional tests. These tests are done while the child is in the hospital. These tests include:

• Imaging
• Magnetic resonance imaging (MRI). This is a type of imaging study that takes a picture of the brain or other parts of the body using a large magnet and radio waves. Depending on the child’s age, sedation may be needed.
• Spinal tap. The doctor will remove a sample of fluid surrounding the brain and spinal cord. The lab tests for signs of inflammation and helps rule out other causes such as infection. Depending on the child’s age, sedation may be needed.
• Blood work. This rules out other infectious and inflammatory diseases that may have similar symptoms.
• Electroencephalogram (EEG). Stickers placed on the head to look at brain wave activity. This helps to look for signs of seizures or other signs of brain dysfunction.
• Other tests, including additional blood work and respiratory viral swabs, may be considered depending on the child’s history and results of the above tests.

What is the Treatment for ADEM?

Your child will be admitted to the hospital for testing and diagnosis and will receive treatment during their admission. Your child will likely be in the hospital for one to two weeks or so, but this can vary depending on how they respond to treatment. The categories of ADEM treatment include:

• Early antibiotic/antiviral treatment. These are used while infectious causes are ruled out.
• Treatment of active inflammation. There are three common treatments used while in the hospital to help reduce inflammation and the autoimmune response:
• Steroids often are given to reduce inflammation from an active flare-up.
• IVIG. This is an infusion of immunoglobulins (antibodies) that helps prevent the immune system from attacking the normal tissue.
• Plasma Exchange (PLEX). This is a procedure where blood is slowly filtered, antibodies are removed, and cleaned blood is returned to the child.
• Prevention of further relapses. Medicines called immunotherapies or immunosuppressants may be needed to prevent future relapses. This often includes continuing steroids by mouth, or IVIG. Initial treatment is done in the hospital, but maintenance treatments are done in clinic.
• Treatment of symptoms related to ADEM. Medicines used to treat symptoms vary depending on the symptoms caused by ADEM. These medicines may be used during active inflammation or may be needed long term. Psychologists and psychiatrists will treat mood and cognitive symptoms with talk therapy, sometimes with the addition of medication, as needed. Occupational, speech and physical therapies are used to help recovery from symptoms.

The cause of ADEM determines how likely it is to recur and whether additional treatments are needed. The specific antibody can help identify the type of maintenance immunotherapies used, and how long they may be needed. Doctors will help guide that discussion and will watch closely for new symptoms and repeat testing as needed.

What is the Long-Term Outlook for ADEM?

Many patients may only have one ADEM attack. Most children recover well with prompt therapy. Recovery usually happens over weeks to months, with around 75% having no long-term symptoms. The risk of having another ADEM attack after a first event depends on if an antibody is found, but ranges between 30-50%.

The antibody testing usually comes back after the initial testing is complete. Antibodies are tested in the blood and spinal fluid. Any lingering symptoms can include weakness, seizures, visual changes and cognitive difficulties. With treatment, most children do not develop significant disability from ADEM.