Acute disseminated encephalomyelitis (ADEM) is a short and sudden bout of inflammation in the brain, spinal cord and, sometimes, the optic nerves. This inflammation damages the protective myelin (white fatty tissue that surrounds nerves) in the brain. ADEM is a demyelinating disorder, which is any condition that damages the myelin.
The inflammation usually occurs one to two weeks after a viral or bacterial infection, such as a sore throat or cough. ADEM very rarely occurs within three months after a child receives a vaccination for measles, mumps and rubella (MMR vaccine). The infection or vaccination triggers an autoimmune response, causing the body’s immune system to attack its own healthy myelin tissue.
The damaged myelin and resulting inflammation cause a variety of symptoms. Symptoms of acute disseminated encephalomyelitis include:
ADEM is typically a one-time event that most often affects children younger than 10 years old, although it can recur within a few months of the initial episode. The condition affects 1 in every 125,000 to 250,000 individuals each year. The condition occurs most often in winter and spring.
The symptoms of ADEM are similar to other conditions, including pediatric multiple sclerosis , optic neuritis (inflammation in the bundle of nerves that sends signals from the eye to the brain), transverse myelitis (inflammation in the spinal cord) and recurrent ADEM (acute disseminated encephalomyelitis that returns).
If your child shows signs of ADEM, a neurologist will perform specific tests to make an accurate diagnosis. Most children with ADEM make a complete and full recovery. Recovery time may take only a few days, but some cases may take up to a year to heal. Some children may continue to have some symptoms, such as blurred vision, numbness or weakness.
Doctors at Riley at IU Health perform the following exams and tests to diagnose acute disseminated encephalomyelitis:
If repeated bouts of demyelinating symptoms occur, or if old and new lesions can be seen on an MRI exam, your child’s doctor may recommend further tests to check for other conditions, such as pediatric multiple sclerosis. The presence of older lesions on an MRI image may indicate multiple sclerosis, which can cause brain lesions before symptoms appear. A single episode of ADEM causes widespread myelin damage, while multiple sclerosis causes many attacks over time.
Treatments for acute disseminated encephalomyelitis focus on reducing inflammation around the nerves to stop symptoms. Treatments include:
If ADEM recurs within a few months, corticosteroids are restarted.
View these links to discover support groups and more resources for ADEM.
Riley at IU Health offers a broad range of supportive services to make life better for families who choose us for their children's care.
This association's website includes information on symptoms, diagnosis, treatment and prognosis of ADEM, a listing of clinical trials, a message forum and access to a physician network.
This National Institutes of Health website offers information about the symptoms, treatment and prognosis for patients with acute disseminated encephalomyelitis, as well as links to clinical trials.
Pediatric neurologists at Riley at IU Health work closely with researchers, neurologists and neuroscientists at the Stark Neurosciences Research Institute at the Indiana University School of Medicine and the Indiana Clinical and Translational Sciences Institute, where research studies related to acute disseminated encephalomyelitis are underway.