What are the causes and/or risk factors associated with acute disseminated encephalomyelitis?

What are the causes and/or risk factors associated with acute disseminated encephalomyelitis?

We know that ADEM usually follows an infection of some kind. In 50 to 75 percent of cases, the beginning of the disease is preceded by a viral or bacterial infection, usually a sore throat or cough (upper respiratory tract infection). Many different bacteria, viruses and other infections have been related to ADEM, but the disease does not appear to be caused by any one infectious agent. Most cases of ADEM begin about 7 to 14 days after the infection.

ADEM appears to be an immune reaction to the infection. In this reaction, the immune system, instead of fighting off the infection, causes inflammation in the central nervous system. Inflammation is defined as the body's complex biological response to harmful stimuli, such as infectious agents, damaged cells, or irritants. Inflammation is a protective attempt to remove the injurious stimuli and initiate the healing process. In the case of ADEM, the immune response is also responsible for demyelination, a process in which the myelin that covers many nerve fibers is stripped off.