Susac’s Syndrome

Abstract

Susac’s syndrome is a rare multisystemic disease characterized by a clinical triad of encephalopathy, hearing loss, and visual disturbances. These deficits result from a microangiopathy involving the brain, cochlea, and retina producing the pathognomonic findings of corpus callosum lesions on brain MRI, branch retinal artery occlusion on fluorescein angiography, and low-moderate frequency hearing loss on audiometry. This microangiopathic disease is thought to be secondary to an autoimmune process although no specific causative antibody has been identified. The disease is most common among young women although pediatric cases in both sexes have been described. Disease progression is variable and can manifest primarily with either encephalopathy or with recurrent retinal involvement. Most cases do not initially present with the complete clinical triad, but a majority of patients eventually have involvement of all three systems. Treatment is difficult and is centered on the use of long-term immunosuppressant agents (corticosteroids, intravenous immunoglobulin, rituximab, etc.). Outcomes are variable with residual visual, auditory, and neuropsychological symptoms persisting in many patients.