Acute disseminated encephalomyelitis: postinfectious, postimmunization and variant forms.

Acute disseminated encephalomyelitis is not an uncommon disorder and affects both children and adults, being more frequent in the younger group. It is said to constitute one third of all encephalidities and usually follows in the wake of a banal viral infection, but may occur after immunizations and as a complication of diseases affecting the cerebral endothelial cells. There is no specific diagnostic test but a good clinical history, attention to clinical findings along with MRI scan often help to make the diagnosis. Treatment with high dose steroids clearly helps as do immunosuppressives and plasma exchange. Whilst the prognosis is generally good, some series have shown 20% mortality, often with high morbidity.