Can ADEM be Triggered by a Vaccine?
Yes. Although rare, viral infections or vaccination sometimes trigger ADEM. However, doctors sometimes first diagnose ADEM as a severe first attack of multiple sclerosis (MS). This is because some of the symptoms of the two disorders, particularly those caused by demyelination, overlap.
Different from multiple sclerosis, though, ADEM usually shows symptoms of encephalitis (fever, coma), and symptoms of myelin damage (vision loss, paralysis). MS usually does not show encephalitis-like symptoms. In addition, ADEM usually consists of a single episode or attack, while MS features many attacks over the course of time. Similarly to ADEM, MS can also be triggered by viral infection or vaccination.
Prognosis of ADEM Triggered by Vaccination
Corticosteroid therapy typically shortens the duration of neurological symptoms of ADEM, while also halting further progression of the disease in the short-term. The long-term prognosis for individuals varies significantly. Studies indicate that half of all patients with ADEM will eventually completely recover. Unfortunately, that means the other half that will not. Of those, the prognoses vary greatly.