Acute Disseminated Encephalomyelitis (ADEM) or acute demyelinating encephalomyelitis is thought to be an autoimmune disorder in which the body’s immune system attacks its own brain tissue. It damages the myelin – the protective covering of nerve fibers - of the brain and the spinal cord and sometimes the optic nerve.
|An illustration of a myelin map in the human brain |
from a paper by HCP researchers Matt Glasser and David Van Essen,
published by the Journal of Neuroscience
ADEM is more common in children than it is in adults. More than 80 percent of childhood cases occur in patients younger than 10 years old. Most of the remaining cases occur between the ages of 10 and 20. In more than 50% percent of ADEM cases, the inflammatory attack is preceded by a viral or bacterial infection. Most cases begin about 7 to 14 days after an infection or following a vaccination. In some cases of ADEM, no preceding event is identified.
Symptoms of ADEM include fever, headache, confusion, altered level of consciousness ranging from lethargy to coma, acute cognitive dysfunction, behavioral changes, vomiting and seizures in about a third of those diagnosed. Neurologic signs of ADEM include decreased voluntary movement, muscle weakness on one side of the body, decreased muscle coordination and damage of cranial nerves.
Transverse Myelitis Association
Cleveland Clinic Acute disseminated encephalomyelitis (ADEM)
Medscape Acute Disseminated Encephalomyelitis Author: J Nicholas Brenton, MD; Chief Editor: Tarakad S Ramachandran, MBBS, FRCP, FRCPC
NINDS Acute Disseminated Encephalomyelitis Information Page. 2010
PubMed Article: Acute disseminated encephalomyelitis (ADEM)
National MS Society: Acute Disseminated Encephalomyelitis (ADEM)