Acute Disseminated Encephalomyelitis (ADEM)
Acute disseminated encephalomyelitis (ADEM) is a rare autoimmune inflammatory condition that affects the brain and spinal cord. It typically occurs after a viral infection or, less commonly, following vaccination, causing widespread damage to the protective myelin coating of nerve fibers.
What is it?
Acute disseminated encephalomyelitis (ADEM) is an immune-mediated inflammatory disorder that causes a brief but intense attack of inflammation in the brain and spinal cord. This inflammation damages the myelin sheath, disrupting nerve signal transmission.
ADEM is rare (0.4 to 0.8 cases per 100,000 annually) and predominantly affects children under age 10. It typically develops days to weeks after a viral infection or vaccination. Unlike multiple sclerosis, ADEM is usually a single episode without recurrence.
Important to Know
ADEM is a medical emergency requiring prompt diagnosis and treatment. With early intervention using immunotherapy, most patients recover well, though the initial symptoms can be severe and frightening. The distinction between ADEM and the first presentation of multiple sclerosis can be challenging and requires careful clinical and imaging evaluation over time.