Primary central nervous system vasculitis with optic nerve involvement

A 20-year-old woman presented with headache, decreased vision, eye pain, and urinary retention. During her clinical course, visual acuity declined to 20/800, right eye, and 20/50, left eye, associated with bilateral optic disc edema. Brain magnetic resonance imaging revealed enhancement of the leptomeninges, right optic nerve, and right side of the optic chiasm. Extensive evaluation of the central nervous system (CNS) for an infectious cause was negative. Brain biopsy showed a pattern consistent with vasculitis. The patient was treated with prednisone and cyclophosphamide, resulting in improvement of her vision and systemic symptoms. Primary CNS vasculitis is a rare condition that may affect the anterior visual pathways.