Susac syndrome is an immune-mediated, pauci-inflammatory, ischemia-producing, occlusive microvascular endotheliopathy/basement membranopathy that affects the brain, retina, and inner ear. Treatment of Susac syndrome is particularly challenging. The organs involved can easily become irreversibly damaged, and the window of opportunity to protect them is often short. Optimal outcome requires rapid and complete disease suppression. Adding to the challenge is the absence of objective biomarkers of disease activity and the great variability in presentation, timing and extent of peak severity, duration of peak severity, and natural disease course. There have been no randomized controlled trials or prospective treatment studies. We offer treatment
guidelines based on cumulative clinical experience and a large cohort of patients followed longitudinally in a comprehensive database project. These
guidelines state our preferences but do allow flexibility and discuss other options. The
guidelines also serve as an initial step in the planning of prospective treatment studies, future
consensus-based recommendations, and future randomized controlled trials.