Susac Syndrome Revisited: A Novel Presentation (2177)

Objective: To review a rare case presentation of Susac Syndrome (SS). Background: In 1979, SS was first described as the triad of subacute encephalopathy, branch retinal arteriolar occlusions (BRAO) and sensorineural hearing loss (SNHL). Patients present with corpus callosal infarcts which appear as “holes” on MR imaging and fluorescein retinal angiography produces pathognomonic multifocal staining as a result of the retinal ischemia. We present the following case to emphasize that SS should be considered even in the presence of an incomplete triad. Design/Methods: Case report Results: A 29-year-old female with a ten year history of migraines presented as an outpatient with thrombocytopenia and an atypical aura. While her usual aura consisted of a transient scotoma, this was ‘a dark spot’ in her peripheral vision which progressively increased in size over days. Her hematologic workup for the thrombocytopenia was negative. Ophthalmology exam demonstrated a left superonasal retinal artery occlusion. Fluorescein angiogram revealed left-sided peripheral vascular non-perfusion and retinal vascular leakage. Her neurological examination and audiometry testing were otherwise normal. Cerebrospinal fluid analysis was unremarkable. Her MR imaging showed classic T2 hyperintense ‘snowball lesions’ along the callosal undersurface. She was diagnosed with SS and treated with prednisone, IVIG, and mycophenolate mofetil. Her repeat fluorescein angiogram revealed marked improvement after treatment. Conclusions: While headaches have been associated with SS, the visual aura usually consists of photopsias as opposed to a progressively worsening peripheral blind spot. Thus, a change in typical aura or new aura in a patient with headaches should prompt further investigation. We report a case of SS which was not associated with any encephalopathy or hearing loss but rather, presented with atypical visual aura and thrombocytopenia which has previously not been described in the literature. We hypothesize that the underlying pathophysiology may be disruption of the glycoprotein receptors on the platelets’ surface via anti-endothelial cell antibodies. Disclosure: Dr. Zaeem has nothing to disclose. Dr. Blevins has nothing to disclose. Dr. Jivraj has nothing to disclose. Dr. Hussain has nothing to disclose.