Acute Disseminated Encephalomyelitis

Excerpt

Acute disseminated encephalomyelitis (ADEM), or post-infectious encephalomyelitis, is an acute, intense, polyfocal, inflammatory autoimmune disorder affecting the central nervous system (CNS). Children are predominantly affected, yet adult cases are not uncommon. ADEM is characterized by demyelination in the brain and spinal cord, and occasionally the optic nerve, due to inflammation that occurs in response to a preceding infection or immunization. The diagnosis is mainly clinical, with typical imaging findings on brain magnetic resonance imaging (MRI). The International Pediatric Multiple Sclerosis Study Group developed the modern diagnostic criteria, defining ADEM as an acute demyelinating syndrome that requires the presence of encephalopathy, polyfocal CNS involvement, and demyelinating lesions on brain MRI.