Abstract
Acute disseminated encephalomyelitis (ADEM) is a rare immune-mediated demyelinating disorder primarily observed in children, typically triggered by recent vaccination or viral infection. Although uncommon, there have been reports of ADEM occurring in adults, with varying radiological findings compared to pediatric cases. Distinguishing ADEM from other demyelinating disorders, such as multiple sclerosis (MS) and neuromyelitis optica (NMO), can pose a diagnostic challenge. We present a case report of an 18-year-old male with a history of polysubstance use who was successfully treated with corticosteroids and highlight the neuroradiological presentation of ADEM, emphasizing the importance of accurate diagnosis and management in both pediatric and adult populations.