What It Is

Acute Disseminated Encephalomyelitis (ADEM) is a demylelinating diseases, most commonly occurring after an acute bacterial or viral infection or, less commonly, following the vaccination for measles, mumps, and rubella.  An autoimmune attack upon the nervous system causes widespread inflammation in the brain and spinal cord that damages myelin.  

What This Means

According to the National Institute of Neurological Disease and Stroke:

ADEM is sometimes misdiagnosed as a severe first attack of multiple sclerosis (MS), since the symptoms and the appearance of the white matter injury on brain imaging may be similar.  However, ADEM has several features which differentiate it from MS.  First, unlike MS patients, persons with ADEM will have rapid onset of fever, a history of recent infection or immunization, and some degree of impairment of consciousness, perhaps even coma; these features are not typically seen in MS.  

Children are more likely than adults to have ADEM, whereas MS is a rare diagnosis in children.  In addition, ADEM usually consists of a single episode or attack of widespread myelin damage, while MS features many attacks over the course of time. 

Doctors will often use imaging techniques, such as MRI (magnetic resonance imaging), to search for old and new lesions (areas of damage) on the brain.  The presence of older brain lesions on MRI suggest that the condition may be MS rather than ADEM, since MS can cause brain lesions before symptoms become obvious.  

In rare situations, a brain biopsy may be necessary to differentiate between ADEM and some other diseases that involve inflammation and damage to myelin.


Symptoms such as fever, fatigue, headache, nausea, and vomiting can appear quickly, followed by vision loss in one or both eyes, overall body weakness, and difficulty coordinating voluntary muscle movements.  In moderate cases, symptoms can be treated and the longterm prognosis is generally favorable.  

Children with the severe cases of ADEM may experience seizures and even slip into a coma.  In very rare but extreme cases, ADEM can be fatal.  

Treatments & Therapies

Immediate steps involve targeted treatment at suppressing brain inflammation.  Several days of intravenous corticosteroids followed by a regiment of oral corticosteroids has proven to help the recovery from most symptoms.

If corticosteroids fail, "plasmapheresis or intravenous immunoglobulin therapy are possible secondary treatment options that are reported to help in some severe cases."  

  • The description of this disease is provided courtesy of the NIH, and other sources.
  • The information provided on this web site should NOT be used as a substitute for seeking professional medical diagnosis, treatment or care. You should not rely on any information in these pages to replace consultations with qualified health professionals.