acute disseminated encephalomyelitis

Acute disseminated encephalomyelitis (ADEM) is a rare acute inflammatory demyelinating disorder of central nervous system characterized by multifocal white matter involvement. Children and young adults are more commonly affected.

Acute disseminated encephalomyelitis (ADEM) is an inflammatory demyelinating disorder of the central nervous system (CNS).

It is predominantly a pediatric disease with an incidence of 0.4/100,000. Also known as post-infectious encephalomyelitis, it typically follows a minor infection with a latency period of 2–30 days and is thought to be immune-mediated. The onset of ADEM usually follows a viral infection or immunization after a mean period of 7-14 days.

ADEM is clinically characterized by the acute onset of focal neurological signs and encephalopathy. Cerebrospinal fluid (CSF) analysis usually shows predominant lymphocytic pleocytosis but, unlike viral or bacterial encephalitis, no evidence of direct CNS infection is found.

Cerebral magnetic resonance imaging (MRI) is essential to ADEM diagnosis, detecting multifocal or diffuse lesions throughout the white matter.

The pathogenesis is not clear but several evidences support the autommune aetiology. ADEM is characterized by multifocal neurological signs and occasionally it rapidly progresses to coma.

Acute disseminated encephalomyelitis (ADEM) is a monophasic, demyelinating disease of the central nervous system that predominately affects prepubertal children. It is typically characterized by an abrupt onset of neurologic symptoms preceded by an infection or recent immunization.

ADEM is a diagnosis of exclusion in many cases, though the differential diagnosis is extensive.

Associations

 varicella infection (18029277)
 Mycoplasma pneumonia (17661054)
 classic dengue (17568897)
 mastoid surgery (17517165)
 multiple myeloma (17515558)

See also

 childhood inflammatory demyelinating CNS disorders

• neuromyelitis optica (NMO)-IgG

Revuews

 Harris C, Lee K. Acute disseminated encephalomyelitis. J Neurosci Nurs. 2007 Aug;39(4):208-12. PMID: 17847667

 Menge T, Kieseier BC, Nessler S, Hemmer B, Hartung HP, Stüve O. Acute disseminated encephalomyelitis: an acute hit against the brain. Curr Opin Neurol. 2007 Jun;20(3):247-54. PMID: 17495616

 Menge T, Hemmer B, Nessler S, Wiendl H, Neuhaus O, Hartung HP, Kieseier BC, Stuve O. Acute disseminated encephalomyelitis: an update. Arch Neurol. 2005 Nov;62(11):1673-80. PMID: 16286539

 Mihai C, Jubelt B. Post-infectious encephalomyelitis. Curr Neurol Neurosci Rep. 2005 Nov;5(6):440-5. PMID: 16263054

References

 Sawanyawisuth K, Phuttharak W, Tiamkao S, Boonpila A. MRI findings in acute disseminated encephalomyelitis following varicella infection in an adult. J Clin Neurosci. 2007 Dec;14(12):1230-3. PMID: 18029277

 Sonneville R, Demeret S, Klein I, Bouadma L, Mourvillier B, Audibert J, Legriel S, Bolgert F, Regnier B, Wolff M. Acute disseminated encephalomyelitisin the intensive care unit:clinical features and outcome of 20 adults. Intensive Care Med. 2007 Nov 9; PMID: 17992509