Abstract
Acute disseminated encephalomyelitis (ADEM) is a monophasic demyelinating disorder predominantly affecting children. It typically follows a viral illness or vaccination. We present a case of a 34-year-old white male treated with chemo-radiotherapy for nasopharyngeal cancer who developed ADEM. Prompt initiation of intravenous steroids led to the resolution of symptoms and normalization of the brain imaging. We hypothesized that direct brain tissue damage by chemotherapy and radiation therapy, combined possibly with a viral infection, triggered an immune inflammatory response and subsequent demyelination.