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Genetic and Rare Diseases Information Center (GARD)

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Acute disseminated encephalomyelitis

Other Names for this Disease
  • ADE
  • ADEM
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Your Question

One of my relatives was diagnosed with acute disseminated encephalomyelitis in 1997. Due to poor medical care, he has not received consistent treatment and his health has deteriorated over the years. He is now completely paralyzed. Is it too late for treatment to be effective? What is the prognosis for an individual who has not been treated promptly?

Our Answer

We have identified the following information that we hope you find helpful. If you still have questions, please contact us.

What is acute disseminated encephalomyelitis (ADEM)?

Acute disseminated encephalomyelitis (ADEM) is a neurological condition characterized by a brief but intense attack of inflammation in the brain and spinal cord that damages myelin – the protective covering of nerve fibers.  It often follows viral infection, or less often, vaccination for measles, mumps, or rubella. Treatment for ADEM is targeted at suppressing inflammation in the brain using anti-inflammatory drugs. Plasmapheresis or intravenous immunoglobulin therapy may also be used.  Additional treatment is symptomatic and supportive.[1] 
Last updated: 10/31/2011

What are the signs and symptoms of acute disseminated encephalomyelitis (ADEM)?

The symptoms of acute disseminated encephalomyelitis (ADEM) come on quickly, beginning with encephalitis-like symptoms such as fever, fatigue, headache, nausea and vomiting, and in severe cases, seizures and coma.  It may also damage white matter (brain tissue that takes its name from the white color of myelin), leading to neurological symptoms such as visual loss (due to inflammation of the optic nerve) in one or both eyes, weakness even to the point of paralysis, and difficulty coordinating voluntary muscle movements (such as those used in walking).  ADEM is sometimes misdiagnosed as a severe first attack of multiple sclerosis (MS), since some of the symptoms of the two disorders, particularly those caused by white matter injury, may be similar.  However, ADEM usually has symptoms of encephalitis (such as fever or coma), as well as symptoms of myelin damage (visual loss, paralysis), as opposed to MS, which doesn’t have encephalitis symptoms.  In addition, ADEM usually consists of a single episode or attack, while MS features many attacks over the course of time.[1]
Last updated: 7/27/2011

What causes acute disseminated encephalomyelitis (ADEM)?

Acute disseminated encephalomyelitis (ADEM) may develop in the wake of a wide variety of infectious illnesses or immunizations. The agents most commonly identified include Epstein-Barr virus, cytomegalovirus, herpes simplex virus (HSV), and mycoplasma.  ADEM is somewhat more common in the colder months of the year, during which these various viral illnesses are more prevalent. Prior to widespread immunization programs, measles was the most common associated illness. Now, most cases occur in the wake of respiratory or gastrointestinal illnesses that are presumed to be caused by viral infections; specific viral agents are seldom identified.[2]

Clear links between the Pasteur rabies vaccine and ADEM have been established. Immunizations less frequently associated with ADEM include pertussis, measles, Japanese B virus, tetanus, and influenza.[2]
Last updated: 10/31/2011

How might acute disseminated encephalomyelitis (ADEM) be treated?

Treatment for acute disseminated encephalomyelitis (ADEM) is targeted at suppressing inflammation in the brain using anti-inflammatory drugs. Most individuals respond to intravenous corticosteroids such as methylprednisolone.  When corticosteroids fail to work, plasmapheresis or intravenous immunoglobulin therapy has been shown to produce improvement.  Additional treatment is symptomatic and supportive.[1]
Last updated: 7/27/2011

What is the prognosis for individuals with acute disseminated encephalomyelitis (ADEM)?

Corticosteroid therapy can shorten the duration of neurological symptoms and halt further progression of the disease in the short term, but the long term prognosis for individuals with ADEM varies.  For most, recovery begins within days, and half will recover completely.  Others may have mild to moderate lifelong impairment.  Severe cases of ADEM can be fatal.  Some individuals initially diagnosed as having ADEM will later be reclassified as MS, but there is currently no method to determine whom those individuals will be.[1] 
Last updated: 7/27/2011

Is it too late to start proper treatment in order to reverse or stabilize my relative's health?

Although we haven't been able to locate any studies which discuss the usefulness of delayed treatment, corticosteroid therapy has been shown to shorten the duration of neurological symptoms and halt further progression of the disease in general.[1] We recommend that you discuss your concerns with a healthcare provider familiar with the details of your relative's case. 
Last updated: 4/28/2009

What is the prognosis for individuals who do not receive treatment in a timely manner?

Early treatment of prednisolone is one of the most important factors to determine the prognosis in this disease.[3][4] However, whether any available form of treatment has a favorable effect on the time to maximal recovery or the risk for deficits is unknown.[2]
Last updated: 4/28/2009