705 - Unmasking Susac Syndrome - The Silent Triad: When Vision, Hearing, and Mind Collide

 A 36-year-old male with a history of immune thrombocytopenia (ITP) and hemochromatosis presented with headache, lethargy, and confusion. He was found to have multi-focal embolic appearing infarctions attributed possibly to ITP and previous treatment with Romiplostim. He received pulse dose steroids and was discharged home. Over the following weeks he developed hearing loss and progressively worsening encephalopathy, found to have numerous T2/Flair hyperintense supra/infratentorial lesions with involvement of the corpus callosum, cerebral edema, and extensive leptomeningeal enhancement in addition to branch retinal artery occlusion (BRAO) for which he was diagnosed with Susac Syndrome. He was treated with a combination of Rituximab, IVIG, high-dose corticosteroids and discharged to IPR. He had significant impairments in processing speed and attention, right > L upper and lower extremity weakness, and impaired balance and coordination. He improved in all of these domains during his multidisciplinary rehabilitation stay with continued IVIG and corticosteroid use. 

Discussions:

Susac Syndrome is a rare immune-mediated endotheliopathy characterized by encephalopathy, sensorineural hearing loss, and branch retinal artery occlusions via endothelial cell injury precipitating vascular occlusion and tissue ischemia. Treatment involves aggressive immunosuppression such as with high dose corticosteroids and IVIG, however, low rates of disease have resulted in treatment recommendations primarily being from empirical evidence in the form of retrospective case series and expert opinion. Diagnosis is complicated by variable presentations and symptom overlap with conditions such as Multiple Sclerosis leading to late diagnosis and treatment, which puts patients at risk of suffering from irreversible cognitive deficits, vision, and hearing loss with risk for relapse. 

Conclusions: Susac Syndrome is a rare disease process presenting challenging diagnostic and treatment questions for which multidisciplinary rehabilitation is a necessary intervention given its broad neuromuscular and cognitive sequelae.