Unusual flare up of Susac syndrome

Abstract

Introduction. Spinal cord involvement as a flare-up of Susac syndrome (SuS) is rarely reported in the literature. The pathogenesis of SuS includes multiple occlusions in micro vessels mediated by an autoimmune response to unknown antigens. This condition is characterized by a triad: central nervous system (CNS) dysfunction with a frequent involvement of the corpus callosum in brain MRI, visual disturbances due to branch retinal artery occlusion, and sensorineural hearing impairment.
 Case report. A 50-year-old man presented in December 2019 symptoms associating gait instability, diplopia and hypoacusis. A year later, he developed a vesical-sphincter disorder and a hypoesthesia in his right lower limb. Neurological examination identified a medullary syndrome, cerebellar ataxia and hypoacusis. We performed a brain and spinal MRI showing supratentorial and infratentorial white matter lesions, and gadolinium enhancing cervical lesions. Lumbar puncture with isoelectric focusing results was normal. Screening for differential diagnosis such as other inflammatory central nervous system diseases other than multiple sclerosis was performed considering this atypical presentation of the disease; workup of serological, immunological, angiotensin converting enzyme, and tumor markers was negative. A bilateral hearing deficit was confirmed with an audiogram. Retinal angiography showed ischemic retinal vasculitis. We diagnosed the patient with SuS and treated him with intravenous corticosteroids in transition to oral corticosteroids. We noticed a partial regression of his symptoms. Therefore, we highlight the importance of an early diagnosis for SuS to avoid a prognostic turnover of the disease. Spinal cord involvement should not rule out the diagnosis of SuS.