A 14-Year-Old Male With Susac Syndrome: A Case Report.

Abstract

Introduction and importance: Susac syndrome (SuS) is a rare autoimmune microangiopathy involving the brain, retina, and inner ear. It is uncommon in children, and early diagnosis is essential to prevent irreversible deficits.

Case presentation: A 14-year-old boy presented with decreased consciousness following 18 days of excessive sleepiness, vomiting, blurred vision, and unsteady gait. There was no family history of autoimmune diseases. MRI showed "snowball-like" corpus callosum lesions suggestive of SuS. Cerebrospinal fluid (CSF) revealed lymphocytic pleocytosis and elevated protein. He improved partially with intravenous methylprednisolone but later developed status epilepticus, requiring plasma exchange. During steroid taper, he experienced relapses with visual and gait disturbances. Fluorescein angiography (FA) confirmed branch retinal artery occlusions (BRAOs). Immunosuppressive therapy with azathioprine and rituximab was initiated, achieving disease stability.

Clinical discussion: MRI findings of corpus callosum "snowball" lesions are a key clue for early diagnosis. Multimodal management-including corticosteroids, plasma exchange, and long-term immunosuppression-is essential to control relapses and prevent permanent sequelae. The patient's fluctuating course underscores the need for ongoing monitoring.

Conclusion: The identification of snowball lesions in the corpus callosum, in conjunction with a "string of pearls" appearance in the internal capsule, mandates prompt immunotherapeutic intervention. Rituximab is currently regarded as the preferred agent, given that azathioprine has demonstrated limited efficacy in moderating disease activity.