What is ADEM or Acute Disseminated Encephalomyelitis?

ADEM is a rare, neurological disorder characterized by a brief but widespread attack of inflammation (swelling) in the brain and spinal cord, damaging and deteriorating the brain’s myelin (white matter). While it can occur in adults, it’s found largely in children and is often confused with multiple sclerosis (MS).

What Are the Symptoms?

This disorder is often mistaken for MS because they both exhibit similar symptoms and are considered autoimmune disorders. However, ADEM only occurs once, while MS has further, repeated attacks. Additionally, symptoms such as fever, headache, confusion, vomiting, and seizures occur with this disorder but not with MS. Other symptoms include:

  • Bacterial or viral infection one to two week prior
  • Loss of vision
  • Drowsiness
  • Blurry vision or double vision
  • Difficulty swallowing
  • Weakness in the arms and legs
  • Numbness
  • Loss of balance

How Do You Get ADEM?

In roughly 50 to 75 percent of cases, it follows a viral or bacterial infection such as the measles, mumps, or rubella. As such, the development of this disorder is thought to be a reaction by the immune system to the infection. However, instead of fighting off the infection, the immune system attacks the central nervous system, causing inflammation in the brain and spinal cord.

How is it Diagnosed?

In order to diagnose this disorder, doctors will typically perform an MRI to detect old or newly damaged areas of the brain. If there are older damaged areas, then this is typically a sign of MS, but if there are only newly damaged areas, then it’s likely ADEM.

Is There a Treatment?

Treatment is usually conducted with a high dose of intravenous corticosteroid for 3-5 days, although a Plasma Exchange is recommended if there is no improvement after the corticosteroid. While some patients may experience lifelong impairments such as weakness, vision loss, numbness, and other cognitive difficulties, most are expected to make a full recovery.

Helpful Resources

United Leukodystrophy Foundation

National Institute of Health

National Multiple Sclerosis Society


Leukodystrophy Care Network