Suspected measles-mumps-rubella vaccine-related encephalitis: two cases.

The cases of 2 infants who developed acute encephalitis in close temporal proximity to receiving measles-mumps-rubella vaccination are described. One developed modified hypsarrhythmia and recovered completely with adrenocorticotrophic hormone protocol, while the other remains severely neurologically handicapped. The timing between vaccination and symptom onset raises suspicion of the vaccine as the possible cause.