Susac Syndrome: Collaboration is Required for a Diagnosis

Background: Susac Syndrome is a rare auto-immune endotheliopathy that rarely presents with the full triad of branched retinal artery occlusion, encephalopathy and sensorineural hearing loss. The diagnosis of Susac can be a challenge due to the variability in presentation, course and severity of disease. Objective: Diagnosis of Susac requires a careful history, diagnostic procedures such as fluorescein angiography, audiometry and MRI, and most importantly interdisciplinary teamwork, all of which aid in the diagnosis of this rare disorder. Case report: A 38-year-old female with no cardiovascular risk factors developed sudden vision loss in the left eye. Extensive evaluations were negative thus prompting the diagnosis of amaurosis fugax. A few days later, she began experiencing flickers in the left eye with new onset blurring of vision in the right eye that progressed to loss of vision after 3 months, with associated headaches, paresthesias of the lips and extremities, and increasing fatigue. There was no loss of hearing. Retina fluorescein angiography revealed multiple occlusions, hyper fluorescence and leakage from the retinal branches. MRI FLAIR sequence demonstrated several hyperintense lesions in the corpus callosum, corona radiata and centrum semiovale. After collaborative efforts, Susac Syndrome was entertained, and our patient received immunoglobulin and rituximab after relapse on pulsed methylprednisolone, with marked resolution of symptoms. Conclusion: Only a small percentage of patients will present with the triad, however, it is most common to see only 2 out of the 3 as exemplified in our case. Collaborative efforts are required to come to a quick diagnosis. Excellent recovery is expected once diagnosis is made, and patients are commenced on immunosuppressants.