Susac syndrome and associated diagnostic challenges: a case report

Susac syndrome is a rare autoimmune endotheliopathy, with a few hundred cases reported. It is characterized by a triad of encephalopathy, branch retinal artery occlusion, and sensorineural hearing loss. Its pathogenesis involves small vessel vasculitis affecting the cerebrum, retina, and cochlea, primarily seen in young women. Owing to the variable presentation and rarity of the disease, early diagnosis is challenging, often delayed owing to its similarity to other neurological conditions.

We report the case of a 32-year-old Caucasian woman with a history of recurrent miscarriages who initially presented with persistent headaches and facial and arm numbness, which was misdiagnosed as migraine. Despite treatment with sumatriptan and botulinum toxin injections, her symptoms worsened, evolving to disorientation, tinnitus, and progressive sensorineural hearing impairment. Brain magnetic resonance imaging showed multiple punctate hyperintense lesions, especially in the corpus callosum, suggestive of cerebral vasculitis. Retinal fluorescein angiography later revealed bilateral branch retinal artery occlusion. Following clinical and radiological findings, a diagnosis of Susac syndrome was established. The patient was treated with high-dose corticosteroids, cyclophosphamide, and intravenous immunoglobulin, resulting in symptomatic improvement and disease stabilization.

This case underscores the diagnostic complexity of Susac syndrome and the importance of considering it in young patients with unexplained persistent headaches progressing to encephalopathy. Early magnetic resonance imaging and timely intervention with immunosuppressive therapy are critical for managing the disease and preventing irreversible sequelae.