Vaccination-associated acute disseminated encephalomyelitis.

While the basic definition of vaccination-associated acute disseminated encephalomyelitis (ADEM) is relatively clear and easily understandable, it is often difficult to diagnose ADEM based on clinical findings alone. ADEM is actually a heterogeneous clinical syndrome that can be approximately characterized by encephalomyelitis with multiple inflammatory demyelination, autoimmune causes, and relationship with a preceding infection or vaccination. The differential diagnosis of ADEM should exclude the possibility of infectious or other autoimmune encephalitis. The occurrence of vaccination-associated ADEM is influenced by several factors including the health and ethnic status of the vaccinated individual, vaccine components, and environment. Cases suspected of vaccination-associated ADEM should be analyzed cautiously from multi-disciplinary perspectives.