The Classic Triad of Susac Syndrome

A 31-year-old, right handed, previously immunocompetent person, presents with progressive headaches, intermittent visual disturbance, and mild confusion. Examination reveals a superior temporal field defect in the right eye. MRI brain is obtained (sagittal non-contrast T1-weighted image is shown). Lumbar puncture shows 18 white blood cells (87% lymphocytes), protein 196.5 mg/dL, and glucose 60 mg/dL. 

This patient has several characteristic features of Susac syndrome, a rare immune-mediated vasculopathy that mainly affects young people assigned female at birth, but can also affect those assigned male at birth. The classic triad of Susac syndrome — encephalopathy, branch retinal artery occlusion (BRAO), and hearing loss — is present in only a minority of patients. The BRAO was responsible for our patient’s field defect. “Snowball” lesions in the corpus callosum, as shown here, are a characteristic finding. Prompt immunosuppressive therapy is indicated.

Further Reading

Clinical Features, Diagnostic Findings, and Treatment of Susac Syndrome: A Case Series

Figure 1 Medical Case

Susac Syndrome: Clinical Characteristics, Clinical Classification, and Long-Term Prognosis


Kleffner I, Dörr J, Ringelstein M, Gross CC, Böckenfeld Y, Schwindt W, Sundermann B, Lohmann H, Wersching H, Promesberger J, von Königsmarck N, Alex A, Guthoff R, Frijns CJ, Kappelle LJ, Jarius S, Wildemann B, Aktas O, Paul F, Wiendl H, Duning T; European Susac Consortium (EuSaC). Diagnostic criteria for Susac syndrome. J Neurol Neurosurg Psychiatry. 2016 Dec;87(12):1287-1295. doi: 10.1136/jnnp-2016-314295. Epub 2016 Oct 25. PMID: 28103199.

Pereira S, Vieira B, Maio T, Moreira J, Sampaio F. Susac’s Syndrome: An Updated Review. Neuroophthalmology. 2020 May 1;44(6):355-360. doi: 10.1080/01658107.2020.1748062. PMID: 33408428; PMCID: PMC7746245.

Aravind Ganesh, MD, DPhil(Oxon), FRCPC
Vascular and Cognitive Neurologist and Assistant Professor, University of Calgary Department of Clinical Neurosciences

Published March 2, 2022

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