RESUMEN
ABSTRACT: Acute disseminated encephalomyelitis (ADEM) is a relatively rare autoimmune process that causes demyelination of the central nervous system. This condition primarily affects children under age 10 years and can produce symptoms including fever, vomiting, headaches, and altered mental status. Diagnostic criteria include encephalopathy (behavioral changes or altered mental status not explained by fever) and MRI findings of demyelination during the first 3 months of developing symptoms without subsequent new MRI findings. Patients can have full recovery within days to weeks if recognized and treated promptly. This article describes an ED visit and hospital course for a 3-year-old girl with headaches and fatigue who was diagnosed with and treated for ADEM.