Abstract
Marburg's disease is a fatal variant of multiple sclerosis (MS), distinguished by its fulminant, rapidly progressive monophasic course that often leads to patients' mortality within weeks of onset. Owing to its rarity, there are no established treatment guidelines. We present a 34 year-old male who was diagnosed with MS, and magnetic resonance imaging revealed numerous supra- and infratentorial white matter plaques. Steroid pulse therapy, intravenous immunoglobulin, and plasma exchange were ineffective. After excluding other differential diagnoses, Marburg's variant MS was considered, and intravenous cyclophosphamide with methylprednisolone was administered. The patient showed significant and fast clinical improvement adding to the evidence that cyclophosphamide is an effective therapeutic modality for treating this MS variant.