Fundus Photography and Fluorescein Angiography of Susac’s Syndrome
Title: Fundus Photography and Fluorescein Angiography of Susac’s Syndrome
Author: Katherine Hu, BA
Photographer: Glen Jenkins, Cyrie Frye, Danielle Princiotta
Date: 01/12/2015, 03/11/2015, 04/04/2017
Figure 1. Color fundus photography showing retinal whitening along the superior arcade with corresponding fluorescein angiography showing left superior temporal branch retinal artery occlusions. 1/12/2015.
Figure 2. Widefield fluorescein angiography OU with multiple bilateral branch retinal artery occlusions. Hyperfluorescence and vessel leakage seen in OS. 3/11/2015.
Figure 3. Widefield fluorescein angiography OU with multiple new branch retinal artery occlusions. 4/4/2017.
Keywords/Main Subjects: Susac’s syndrome, branch retinal artery occlusion (BRAO), microangiopathy
Diagnosis: Susac’s syndrome
Description of Image:
Susac’s syndrome is a rare, autoimmune microangiopathy involving the brain, retina, and inner ear. The condition can manifest clinically as a triad of encephalopathy, branch retinal artery occlusions (BRAO), and hearing loss, though not all three features may be present during the onset of the disease. Symptoms often include vision loss, headache, confusion, paranoia, vertigo, tinnitus, and deafness. The syndrome tends to occur in females between 20-40 years of age; it has not been associated with an inheritance pattern or family history. While the etiology and pathogenesis of Susac’s syndrome are unclear, the disease is thought to be an autoimmune disorder targeted at endothelial cells in the microvasculature of the brain, retina, and cochlea.
In the brain, MRI findings show distinctive white matter lesions that primarily involve the corpus callosum; abnormalities of the leptomeninges and gray matter may also be present. Audiogram can reveal sensorineural hearing loss. Fluorescein angiography is essential for identifying BRAO, pathognomonic hyperfluorescence of retinal arteriole walls, and small, yellow punctate arteriole wall plaques. Susac’s syndrome is often confused for demyelinating diseases such as multiple sclerosis and acute disseminated encephalomyelitis (ADEM). Other mimics include chronic encephalitis, meningitis, Lyme disease, thromboembolic disease, systemic lupus erythematosus, and CNS vasculitis. The disease is generally self-limiting, however, early and aggressive treatment with immunosuppressive therapy is recommended to avoid long-term sequelae from acute microvascular damage.
The color fundus photographs and fluorescein angiograms above are from patient KO, who is a 29 year-old Caucasian female. She first presented with acute headache, vertigo, worsening confusion, personality/behavioral changes, and partial vision loss in the left eye. Brain MRI showed extensive lesions in the white matter, deep gray, and cerebellar areas with corpus callosal preference, as well as scattered leptomeningeal enhancement. Neurological work up was non-focal and non-contributory. Upon examination, she was found to have a left superior temporal branch retinal artery occlusion visible on both fundus photography and fluorescein angiography (Figure 1). Fundus photography shows a central area of whitening due to ischemia as a result of microvascular occlusion. On subsequent widefield angiography, multiple bilateral BRAO with vascular leakage were seen (Figure 2). The images obtained display characteristic BRAO located distal of the arteriolar bifurcations with associated arteriolar wall plaques that do not resemble emboli or cholesterol plaques. Hyperfluorescence and leakage of the retinal arteriole wall seen are due to active endothelial injury. The patient was treated with high-dose Prednisone, Cellcept, and IVIG with relative stabilization of her disease. However, her clinical course was complicated by multiple microvascular ischemic strokes and new left-sided hearing loss in April 2017 when IVIG was discontinued. Follow-up examination revealed extensive retinal edema inferiorly in the left eye, contiguous with areas of retinal non-perfusion as a result of new BRAO suggesting progression of the disease (Figure 3).
Format: JPG file
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“Susac Syndrome.” Genetic and Rare Diseases Information Center. U.S. Department of Health and Human Services. Web. Accessed 24 June 2017. <https://rarediseases.info.nih.gov/diseases/7713/susac-syndrome>
Faculty Approval by: Akbar Shakoor, MD
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