2. ACUTE DISSEMINATED
ENCEPHALOMYELITIS (ADEM)
(postinfectious,postvaccinal, or allergic
encephalomyelitis)
• ADEM is an acute immune-mediated
demyelinating disorder in which small foci of
demyelination with a perivenous distribution
are scattered throughout the brain and spinal
cord.
• Lesions are 0.1–1.0 mm in diameter.
3.
4. • This disorder may follow upper respiratory and
gastrointestinal infections (viral), viral exanthems
(measles, chickenpox, rubella, etc.) or immunisation
with live or killed virus vaccines (influenza, rabies).
• Measles is the commonest cause occurring in 1 per
1000 primary infections; next Varicella zoster
(chickenpox),
• 1 per 2000 primary infections.
5. Clinical features
• : Within days or weeks of resolution of the viral infection, fever, headache,
nausea and vomiting develop.
• Meningeal symptoms (neck stiffness, photophobia) are then followed by
drowsiness and multifocal
• neurological signs and symptoms – hemisphere brain
stem/cerebellar/spinal cord and optic nerve involvement.
• Myoclonic movements are common.
• Behavior changes such as crankiness or confusion
• Muscle weakness
• Trouble with balance or movement
• Vision problems
• Slurred speech
• Numbness or paralysis on one side of the body
• Seizures
• Coma
6. Pathology
• demyelination is limited to perivascular areas and
lesions do not approach the same size as in MS.
• Pathologically, ADEM is characterized by perivenous
sleeves of inflammation (mainly T- lymphocytes
and macrophages), edema, demyelination, and
axonal loss. The lesions are all of the same age and
affect white matter and gray matter, including
cerebral cortex and deep nuclei. There is microglial
activation in the cortex
7.
8. Causes
• Doctors think ADEM is an autoimmune disease. That
means your immune system attacks your body's own cells
and tissues as if they were bacteria or viruses.
• Experts don't know exactly what triggers it, but it could be
a reaction to an infection.
• Most of the time, the 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. But
research hasn’t found a direct link.
•
• Other times, symptoms seem to come out of nowhere.
9. Risk factors
• Age. More than 80% of cases are in children
younger than 10. Most of the rest are in older kids.
• Sex. Boys are slightly more likely to get it than girls.
• Time of year. Cases in North America peak during
winter and spring.
10. How Is ADEM Different From MS?
• ADEM has a lot in common with multiple sclerosis (MS) and
other diseases that damage myelin. They share some
symptoms, like muscle weakness, numbness, loss of vision,
and loss of balance.
• The differences include:
• MS is rare in children. ADEM is more common.
• Kids with ADEM may have a fever, a headache, seizures, or
trouble thinking clearly. These symptoms are rare with MS.
• The disease usually appears soon after a viral illness. There's
no such link with MS.
• An ADEM attack usually happens once, but multiple sclerosis
involves many episodes over time.
11. Diagnosis
• No diagnosis test.
• CSF – 20–200 mononuclear cells.
• Total protein and γ globulin raised.
• Peripheral blood may be normal or show neutrophilia,
lymphocytosis or lymphopenia.
• The electroencephalogram (EEG) shows diffuse slow wave
activity.
• CT scan is normal..
• MRI shows small focal white matter changes,
simultaneously enhancing with contrast indicating that all
are of the same degree of acuteness (unlike MS).
12. • lumbar puncture (fluid drawn from around the spinal
cord and then tested)
• Diagnosis is straightforward when there is an obvious
preceding viral infection or immunisation. When viral
infection immediately precedes, distinction from acute
encephalitis is often impossible.
• Separation from acute MS may be difficult. Fever,
meningeal signs with elevated CSF protein above 100
mg/ml with cell count greater than 50 per mm3 suggest
ADEM.
13. Treatment
• : Steroids are used, although no controlled trials have been conducted. Large
dosage is recommended during the acute phase. Cyclophosphamide may be
used in refractory cases.
•
• Most people start with high doses of a strong corticosteroid put into a vein
(intravenous, or IV) for a few days. Your child may feel better within hours.
They'll keeping taking a steroid (as a pill or a liquid) for several weeks, in
smaller and smaller doses.
• your child can't have steroids or if they don't work, some procedures can
calm the immune system.
• plasmapheresis..
• Or they could get shots of antibodies from a healthy person, which is called
intravenous immunoglobulin treatment.
•
• After the hospital, they may need physical, occupational, or speech therapy.
They may have to stay in a rehab hospital for a while, or they might be able to
go home and work with a therapist.
14. Outcome
• : The illness is typically monophasic.
• The mortality rate is 20%.
• Full recovery occurs in 50%.
• About 8 times out of 10, ADEM happens only once. But
sometimes, you can get it again within a few months,
especially if you don't take steroids for long enough.
Rarely, children who have ADEM get MS later on.
• About 8 times out of 10, ADEM happens only once. But
sometimes, you can get it again within a few months,
especially if you don't take steroids for long enough.
Rarely, children who have ADEM get MS later on.
15. References
• Melinosky Christopher (july 27,2017). Acute
Dessiminated Encephalomyelitis (ADEM).november
28,2020,
www.webmd.com,https://www.google.com
• Lindsay Kenneth W., Bone Ian, Fuller
Geraint(2010), Neurology And Neurosurgery
Illustrated 5th Edition ,page no. 530, Edinburgh
London New York Oxford Philadelphia ST Louis
Sydney Toronto, Churchill Livingston.