acute disseminated encephalomyelitis (ADEM), an acute disease of the brain and spinal cord with variable symptoms. It is thought to be an allergic reaction or immune attack on the myelin tissue after a viral infection, such as measles, or, less often, after vaccination for measles, mumps, or rubella. Early symptoms may include fever, headache, vomiting, and drowsiness and progress to seizures, coma, and paralysis. It may be misdiagnosed as a severe attack of multiple sclerosis. Frequently patients who recover experience neurological disorders. Also called acute disseminated encephalitis.
