Acute Disseminated Encephalomyelitis (ADEM)
Acute Disseminated Encephalomyelitis (ADEM)
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Acute Disseminated Encephalomyelitis

Author: Alison L. Christy, MD, PhD  
Providence Pediatric Neurology at St. Vincent Medical Center – Portland, Oregon 

Reviewed: July 2021 


Acute Disseminated Encephalomyelitis (ADEM) is most likely an autoimmune disease caused by an infection. It causes symptoms of brain disturbance. Symptoms may include confusion, irritability, unusual sleepiness, and occasionally seizures. ADEM is very rare. It almost always happens after a child is sick. Children usually recover after a few weeks, but may have lasting symptoms. Usually it only happens once and does not occur again. 


Disorder Overview


The immune system is made up of immune cells. Immune cells usually fight off threats from the outside, such as viruses, bacteria, and fungi. In autoimmune diseases, immune cells attack the healthy cells of the body. 

The nerves of the body are like electrical wires. They have a coating on the outside called myelin. In ADEM, immune cells attack the myelin coating on the nerves in the brain. This usually happens 4-14 days after an illness like a cough or a sore throat. In rare cases, it can occur after a vaccination.  

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The primary symptom of ADEM is encephalopathy. 

Encephalopathy is a broad term that means symptoms of brain disturbance, including:  

  • Confusion
  • Unusual behaviors
  • Unusual sleepiness (lethargy, somnolence)
  • Problems with memory
  • Personality changes
  • Irritability

Encephalopathy is required for the diagnosis of ADEM.

Other symptoms can include: 

  • Fever
  • Headaches
  • Nausea
  • Poor balance (ataxia)
  • Changes in vision
  • Seizures
  • Changes in movement or sensation


ADEM almost always occurs in young people under the age of 10. It is slightly more common in boys than in girls.   

The cause of ADEM is not known. However, in about half of cases, children experience a “cold,” with fever, cough, and runny nose, less than two weeks before developing ADEM. We think that a viral infection may “trigger” the attack. The infection can cause the body’s immune system to damage the myelin sheath around nerves in the brain.    


In ADEM, pictures of the brain and/or spinal cord look abnormal. These pictures are created with magnetic resonance imaging, or MRI. MRI can show areas where myelin has been damaged. The damaged areas are called lesions. A medicine called contrast may be used to help see lesions.  

The pattern of the lesions can help the doctor know that a patient has ADEM. It can distinguish ADEM from other diseases that affect myelin, like multiple sclerosis or neuromyelitis optica.   

Lesions in the brain in ADEM can be very large. However, they will usually disappear completely with time and medicines. The size and number of lesions on an MRI does not predict how well a patient will recover after a diagnosis of ADEM.  

Sometimes, the doctor will do more tests to confirm a diagnosis.

These may include: 

Blood tests

Doctors may look for signs of infection, or for certain types of antibodies in the blood. 

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A lumbar puncture

This can test the cerebrospinal fluid that surrounds the brain and spine. It can be used to show that symptoms are not caused by an active brain infection, like meningitis or encephalitis.

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Acute Disseminated Encephalomyelitis 3


If a child is diagnosed with ADEM, a doctor may offer medicines that change the way the immune system works.

These can include:

  • Steroids
  • Therapeutic plasma exchange (also called plasmapheresis)
  • Immunoglobulin G, or antibodies from other people (known as IVIG; this is rare)

Other ways to support a patient can include: 

Antibiotics and Antivirals

Initially, many patients with ADEM will receive medicines that help the body fight bacteria and viruses. This is because the symptoms of ADEM can look like the symptoms of a brain infection. For example, they can look like meningitis or encephalitis. Once the diagnosis of ADEM has been made, the patient usually no longer needs antibiotics. 

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Anti-seizure medications

Some patients may need medicine to prevent seizures. 

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Intubation or feeding tubes

Some children will need help breathing and eating safely. They can receive this are in the hospital.   

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Usually, children will not need long-term treatment to prevent future episodes of ADEM.  

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Most children diagnosed with ADEM will make a full recovery over 4-6 weeks. Some children will continue to have symptoms, including:

  • Weakness of one part of the body
  • An increased risk of seizures (called epilepsy)
  • Problems with vision
  • Problems with focus, concentration, and learning

Most children with ADEM will only have one attack. Repeat attacks of ADEM are possible but rare. If symptoms return, it could mean that a child has a different autoimmune disease, like neuromyelitis optica or multiple sclerosis.

It is rare for children to die of ADEM. A severe form of ADEM, called acute hemorrhagic leukoencephalitis (AHL), may put children at more risk for death.


Siegel Rare Neuroimmune Association  
The Siegel Rare Neuroimmune Association (SRNA) is a not-for-profit international organization dedicated to the support of children, adolescents, and adults with a spectrum of rare neuroimmune disorders including: Acute Disseminated Encephalomyelitis (ADEM), Acute Flaccid Myelitis (AFM), MOG Antibody Disease (MOGAD), Neuromyelitis Optica Spectrum Disorder (NMOSD), Optic Neuritis (ON) and Transverse Myelitis (TM).   

Their mission is to support individuals living with rare neuroimmune diagnoses and their families, promote awareness to empower patients, families, clinicians, and scientists, through education programs (such as the SRNA Quality of Life Family Camp for children and their families diagnosed with a rare neuroimmune disorder) and publications and, to build a collaborative and dedicated clinical care network and help advance scientific understanding and research.  

Childhood Stroke 1

Child Neurology Foundation (CNF) solicits resources from the community to be included on this webpage through an application process. CNF reserves the right to remove entities at any time if information is deemed inappropriate or inconsistent with the mission, vision, and values of CNF. 

Research for Acute Disseminated Encephalomyelitis are clinical trials that are recruiting or will be recruiting. Updates are made daily, so you are encouraged to check back frequently. is a database of privately and publicly funded clinical studies conducted around the world. This is a resource provided by the U.S. National Library of Medicine (NLM), which is an institute within the National Institutes of Health (NIH). Listing a study does not mean it has been evaluated by the U.S. Federal Government. Please read the NLM disclaimer for details.  

Before participating in a study, you are encouraged to talk to your health care provider and learn about the risks and potential benefits. 

The information in the CNF Child Neurology Disorder Directory is not intended to provide diagnosis, treatment, or medical advice and should not be considered a substitute for advice from a healthcare professional. Content provided is for informational purposes only.  CNF is not responsible for actions taken based on the information included on this webpage. Please consult with a physician or other healthcare professional regarding any medical or health related diagnosis or treatment options. 


Krupp LB, Tardieu M, Amato MP, et al. International Pediatric Multiple Sclerosis Study Group criteria for pediatric multiple sclerosis and immune-mediated central nervous system demyelinating disorders: revisions to the 2007 definitions. Mult Scler. 2013 Sept;19(10)1261-7. 

Flanagan EP. Neuromyelitis optica spectrum disorder and other non-multiple sclerosis central nervous system inflammatory diseases. Continuum: Lifelong Learning in Neurology. 2019; 25(3): 815-844 

Lotze TE and Chadwick DJ. Acute disseminated encephalomyelitis (ADEM) in children: Pathogenesis, clinical features and diagnosis. In: UpToDate, Dashe, JF (Ed), UpToDate, Waltham, MA.  

Lotze TE and Chadwick DJ. Acute disseminated encephalomyelitis (ADEM) in children: Treatment and prognosis. In: UpToDate, Dashe, JF (Ed), UpToDate, Waltham, MA.  

The Journal of Child Neurology, 2021. What Your Pediatric Neurologst Wants You to Know: Neuroimmunology. [podcast] SAGE Neuroscience and Neurology. Available at: <>  

National Multiple Sclerosis Society. Acute Disseminated Encephalomyelitis (ADEM). 

National Organization for Rare Disorders. Acute Disseminated Encephalomyelitis. Rare Disease Database. 

Siegel Rare Neuroimmune Association. Acute Disseminated Encephalomyelitis (ADEM). 

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