Walsh & Hoyt: Acute Disseminated Encephalomyelitis (Adem, Postinfections Encephalomyelitis)

In Chapters 57 and 58 of this text, infections of the CNS caused by viral illnesses are discussed in detail. Whereas most of the disorders discussed in these chapters are caused by direct viral invasion of the CNS, some viruses seem to induce a demyelinating encephalomyelitis that results from the immunologic complications of the infection and not from actual damage to the CNS from the virus itself. This condition is called postinfectious or acute disseminated encephalomyelitis (ADEM). Although ADEM is mentioned in Chapter 57, we discuss it in more detail here in order to compare it with MS and the other inflammatory demyelinating diseases.