ADEM (acute disseminated encephalomyelitis) is a rare neurological disorder, a disease that targets the nervous system. Although ADEM can appear at any age, children are more likely than adults to develop it.

ADEM involves inflammation in the brain and spinal cord that damages myelin, the protective covering of nerve fibers. Sometimes doctors misdiagnose ADEM as multiple sclerosis (MS). However, unlike MS patients, people with ADEM have a rapid onset of fever, recent infection or immunization, and some impairment of consciousness. In addition, children are more likely than adults to have ADEM, and MS is rare in children.

Symptoms

The symptoms of ADEM appear rapidly, beginning with fever, fatigue, headache, nausea and vomiting, and in the most severe cases, seizures and coma.

ADEM typically damages brain tissue, leading to symptoms like visual loss in one or both eyes, weakness even to the point of paralysis, and difficulty coordinating voluntary muscle movements (such as those used in walking).

More than 80 percent of childhood cases occur in patients younger than 10 years. Most of the remaining cases occur between the ages of 10 and 20.

Experts believe up to five percent of cases could be associated with vaccination.

Recovery

More than 85 percent of people with ADEM recover fully within a few weeks. Within six months, the majority of ADEM patients will have complete or almost complete recoveries. Most others recover within a few months. Steroid treatments can shorten the duration of an attack.

A small number of people are left with mild cognitive or behavioral changes, such as confusion and drowsiness. Adults may have a harder time recovering than children.

In very rare cases, ADEM can be fatal.

Corticosteroid therapy typically helps speed recovery from ADEM symptoms.

Cause

Doctors think ADEM is an autoimmune disease, meaning a disease where a person’s immune system mistakenly attacks its own body. Experts don’t know exactly what triggers ADEM, but it could be a reaction to an infection. Oftentimes, an ADEM attack happens when a child is getting over a common illness, like a cold or stomach bug.

ADEM sometimes follows a vaccine, especially certain rabies shots and the vaccine for measles, mumps, and rubella (MMR vaccine).

Related disorders

• MS (multiple sclerosis) is a potentially disabling disease of the brain and spinal cord.
• TM (transverse myelitis) is an inflammation of the spinal cord that results from damage to nerve cells.

Contact Us

If you or your child has been diagnosed with ADEM, contact our office for a free consultation with one of our experienced vaccine team members. You may be eligible for compensation from the National Vaccine Injury Compensation Program.

Learn more about ADEM:

• ADEM description from the National Multiple Sclerosis Society
• ADEM description from the National Institute of Neurological Disorders and Stroke
• ADEM description from the Cleveland Clinic