[Acute disseminated encephalomyelitis]

Acute disseminated encephalomyelitis (ADEM) occurs late in the course of viral infection, mainly exanthematous diseases such as measles, chicken pox, and rubella. Postinfectious encephalomyelitis is characterized by immune-mediated demyelination, which is found in experimental autoimmune encephalomyelitis (EAE), and virus cannot be isolated from the central nervous system. The investigations using animal models infected with. Theiler's virus or measles virus would be very useful for clarifying the mechanisms of demyelination induced by viral infection. Although the incidence of postvaccinal encephalomyelitis has fallen markedly due to development of vaccines, the neurological complications following immunization are still reported. The vaccines prepared from viruses other than live-attenuated viruses and whole-killed organisms have never been proved to induce ADEM.