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Show A Case of Isolated Susac Occlusive Retinal Vasculitis Mark E. Seamone, MS, Michael Fielden, MD, FRCSC Abstract: Susac syndrome is characterized by encephalop-athy, sensorineural hearing loss, and branch retinal artery occlusion. Additional ocular findings include arteriolar wall hyperfluorescence and Gass plaques. We present a 51-year-old Caucasian woman with ophthalmologic findings indica-tive of Susac syndrome in the setting of tinnitus and migraine with aura. Journal of Neuro-Ophthalmology 2013;33:260-262 doi: 10.1097/WNO.0b013e31828bb64b © 2013 by North American Neuro-Ophthalmology Society A51-year-old Caucasian woman was referred for retinal vascular sheathing in the right eye with spotty visual field loss and dysphotopsia bilaterally. Review of systems was significant for tinnitus and migraine with aura. Visual acuity FIG. 1. Color and red-free fundus photographs of the right (A, B) and left (E, F) eyes, respectively. Fluorescein angiography shows arteriolar wall hyperfluorescence (arrows) in the right eye (C, D) and branch retinal artery occlusion (arrows) in the left eye (G, H). Faculty of Medicine (MES, MF), University of Calgary, Calgary, Alberta, Canada; and Calgary Retina Consultants (MF), Calgary, Alberta, Canada. The authors report no conflicts of interest. Address correspondence to Michael Fielden, MD, FRCSC, ABO, Calgary Retina Consultants, 200, 5340 1st Street SW, Calgary, Alberta T2H 0C8, Canada; E-mail: mpfielden@gmail.com 260 Seamone and Fielden: J Neuro-Ophthalmol 2013; 33: 260-262 Photo Essay Section Editor: Timothy J. McCulley, MD Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. was 20/20 in the right eye and 20/15 in the left eye. Left fundus examination revealed an inferonasal branch retinal artery occlusion (BRAO) with arteriolar sheathing in both eyes. Fluorescein angiography confirmed BRAO in the left eye and demonstrated arteriolar wall hyperfluorescence (AWH) along the right superotemporal arteriole (Fig. 1). Interestingly, BRAO and AWH occurred at independent locations. An extensive systemic workup failed to reveal an autoimmune or infectious cause of retinal vasculopathy. Given the clinical findings associated with migraine aura and tinnitus, Susac syndrome was considered a potential diagnosis. The patient was placed on a dose of 30 mg of prednisone daily. Three weeks later, visual acuity was stable. Brain magnetic resonance imaging was normal without evidence of corpus callosum microinfarctions. Audiography was also normal. Neurology consultation showed no evidence of encephalopathy. Two weeks later, the patient reported decreased vision in the right eye. She was found to have a BRAO along the right superotemporal arteriolar arcade with the presence of Gass plaques (GPs) (Fig. 2). The location of this BRAO did not correlate with the location of AWH observed on the initial presentation. The patient's prednisone dose was increased to 50 mg daily and then tapered as methotrexate was begun. The patient remains stable on 25 mg of meth-otrexate and 5 mg of folic acid, both taken weekly. There has been no recurrence of retinal vasculitis over 14 months of follow-up. Susac syndrome is a rare neurologic disorder characterized by encephalopathy, sensorineural hearing loss, and BRAO (1). It has been divided into 2 subtypes: 1) encephalopathic with changes in affect and neuroimaging findings of corpus callosum infarcts and 2) retinal vasculitis with BRAO (2). The BRAO subtype is characterized by retinal vasculitis and minimal or absent neurologic involvement. Cochleovestibu-lar involvement may manifest as tinnitus or vertigo (2). The ophthalmologic findings of Susac syndrome include recurrent BRAO, AWH, and GP (3,4). These plaques, thought to be atheromatous in nature, develop in areas of acute arteriolar wall injury. Typically, GP are yellow, may be refractile or nonrefractile, and, in contrast to Hollenhorst plaques, usually are located away from arteriolar bifurcations (3,4). The diagnosis of Susac syndrome often is not considered in the absence of the complete clinical triad. In our patient, the observation of BRAO, GP, and AWH in the setting of tinnitus and migraine is consistent with Susac syndrome. The dissociation between the presence of AWH and BRAO, as seen in our case, is a hallmark of Susac syndrome and lends further support to the diagnosis. We propose 2 explanations regarding the absence of corpus callosum involvement and changes in affect. First, retinal vasculitis may have been the initial disease presentation and progression to fulminant Susac syndrome was halted by the initiation of immunosuppressive FIG. 2. Two weeks after the initial presentation, our patient experienced branch retinal artery occlusion in the right eye (A) with a Gass plaque (arrow) (B). Fluorescein angiography (C-E) confirmed the vascular occlusion (arrow). Seamone and Fielden: J Neuro-Ophthalmol 2013; 33: 260-262 261 Photo Essay Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. agents. Second, this may represent a rare case of BRAO subtype of Susac syndrome. REFERENCES 1. Susac JO, Hardman JM, Selhorst JB. Microangiopathy of the brain and retina. Neurology. 1979;29:313-316. 2. Rennebohm R, Susac JO, Egan RA, Daroff RB. Susac's syndrome-update. J Neurol Sci. 2010;299:86-91. 3. Egan RA, Hills WL, Susac JO. Gass plaques and fluorescein leakage in Susac syndrome. J Neurol Sci. 2010;299:97-100. 4. Egan RA, Ha Nguyen T, Gass JD, Rizzo JF III, Tivnan J, Susac JO. Retinal arterial wall plaques in Susac syndrome. Am J Ophthalmol. 2003;135:483-486. 262 Seamone and Fielden: J Neuro-Ophthalmol 2013; 33: 260-262 Photo Essay Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. |
