Susac syndrome is a rare autoimmune endotheliopathy with predilection for brain, retina, and cochlea (1). A presumed autoimmune vasculitic mechanism has been proposed, resulting in microangiopathy affecting the arterioles of the brain, retina, and cochlea (1–4). The syndrome usually affects women in the second decade of life, with female to male ratio being 3:1 (3,4). To date, approximately 80 cases have been reported. Patients typically present with low-frequency hearing loss were detected with audiometry. Headaches are frequently present in addition to tinnitus and often some degree of paranoia (1–4). Partial vision loss is caused by branch retinal artery vasculitis and occlusions (5,6). Abnormalities on brain magnetic resonance imaging (MRI) always show corpus callosum involvement. The mainstay of treatment is systemic corticosteroids and immunosuppressive medications (6–8).
Central serous chorioretinopathy (CSC) is characterized by a serous macular detachment due to a focal disruption in the outer blood–retinal barrier and increased choroidal permeability (9). Although the pathoetiology of CSC is unknown, it is associated with states of hypercortisolism, such as Cushing syndrome, pregnancy, and systemic glucocorticoid therapy.
We report a patient with Susac syndrome who developed CSC.
A 32-year-old woman reported a 1-week history of blurred vision and metamorphopsia in her left eye. For the past 3 weeks, she had experienced decreased hearing with tinnitus and migraine with aura and complained of an unsteady gait, intermittent paresthesias of the face and lower extremities, emotional lability, and forgetfulness. She was previously healthy and had no remarkable medical history other than cold hands and intermittent hypotension. She had never used topical or systemic corticosteroids.
Visual acuity was 20/20, right eye and 20/40 left eye. The anterior segments of both eyes were unremarkable. Fundus examination revealed bilateral multiple peripheral retinal arteriolar occlusions and serous elevation of the left macula. The sites of retinal arterial occlusion were not localized at arterial bifurcation. Fluorescein angiography demonstrated bilateral peripheral arteriolar wall hyperfluorescence distant to areas of arteriolar segmental occlusion (Fig. 1). In the left eye, there was focal dye leakage near the fovea with a neurosensory retinal detachment (Fig. 2). This was confirmed by optical coherence tomography (Fig. 3).
Neurological examination revealed an ataxic gait and cognitive dysfunction with memory loss. Brain MRI disclosed periventricular white matter lesions and punctuate hyperintense foci within the corpus callosum (Fig. 4). Audiometric evaluation revealed bilateral asymmetric sensorineural hearing loss more pronounced for lower frequencies.
The patient was treated with cyclophosphamide and intravenous immunoglobulin. Steroids were not prescribed because of the presence of CSC. The patient improved dramatically with resolution of her neurologic findings except for a mild hearing deficit. In addition, CSC resolved and fluorescein angiography became normal. Treatment was stopped after 6 months.
Although the pathophysiology of Susac syndrome is unknown, it is believed to be an immune disorder leading to microangiopathy of the precapillary arterioles of the brain, retina, and inner ear (1–5). Brain biopsies have revealed wall sclerosis of small arteries and multifocal microinfarcts with perivascular inflammatory infiltrates of cerebral arteriolar branches (5–8). Two funduscopic findings in patients with Susac syndrome, Gass plaques and arteriolar wall hyperfluorescence, also point to the endothelium as the site of autoimmune injury (5). Fluorescein angiography may reveal arteriolar wall hyperfluorescence distant from affected vessels seen on opthalmoscopy. This finding has not been demonstrated in other retinal vasculitides. Hyperfluorescence of the retinal arteriolar walls may be found both proximally to the site of occlusion but also in areas remote from occluded arterioles (3,5,6,10).
Although there is no histological evidence of choroidal involvement in Susac syndrome, choroidal endotheliopathy could be present in some patients with this disorder (10). Flammer et al (11,12) postulated that the Susac syndrome is a manifestation of primary vascular dysregulation syndrome (PVDS; formerly vasospastic syndrome), and vascular dysregulation is at least one possible cause of Susac syndrome. The majority of patients with PVDS are female, often have low blood pressure and suffer from cold hands that rarely turn white. The ocular vasospastic syndrome denotes eye involvement in this disorder. Vascular dysregulation can be primary or secondary to an autoimmune disease. Disorders of many organ systems, particularly the eye, occur with increased frequency in PVDS individuals. These include silent myocardial infarction, altitude sickness, migraine, normal-tension glaucoma, anterior ischemic optic neuropathy, retinal artery, and vein occlusions, Susac syndrome and CSC (11–13).
Abnormalities in the choroidal circulation and retinal pigment epithelium have been hypothesized to cause CSC (9,13,14). We propose that the endotheliopathy in Susac syndrome may alter choroidal vascular permeability as seen in our patient. This resulted in accumulation of submacular fluid. We are unaware of previous reports of CSC associated with Susac syndrome.
1. Susac JO, Hardman JM, Selhorst JB. Microangiopathy of the brain and retina. Neurology. 1979;29:313–316.
2. Schwitter J, Agosti R, Ott P, Kalman A, Waespe W. Small infarctions of cochlear, retinal, and encephalic tissue in young women. Stroke. 1992;23:903–907.
3. Monteiro ML, Swanson RA, Coppeto JR, Cuneo RA, DeArmond SJ, Prusiner SB. A microangiopathic syndrome of encephalopathy, hearing loss, and retinal arteriolar occlusions. Neurology. 1985;35:1113–1121.
4. Notis CM, Kitei RA, Cafferty MS, Odel JG, Mitchell JP. Microangiopathy of brain, retina, and inner ear. J Neuroophthalmol. 1995;15:1–8.
5. Egan RA, Ha Nguyen T, Gass JD, Rizzo JF, Tivnan J, Susac JO. Retinal arterial wall plaques in Susac syndrome. Am J Ophthalmol. 2003;135:483–486.
6. Seamon ME, Fielden MA. Case of Isolated Susac occlusive retinal vasculitis. J Neuroophthalmol. 2013;33:260–262.
7. Saw VP, Canty PA, Green CM, Briggs RJ, Cremer PD, Harrisberg B, McCluskey P, O'Day J, Paine M, Wakefield D, Watson JD. Susac syndrome: microangiopathy of the retina, cochlea and brain. Clin Exp Ophthalmol. 2000;28:373–381.
8. Susac JO, Murtagh FR, Egan RA, Bergen JR, Bakshi R, Lincoff N, Gean AD, Galetta SL, Fox RJ, Costello FE, Lee AG, Clark J, Layzer RB, Daroff RB. MRI findings in Susac's syndrome. Neurology. 2003;61:1783–1787.
9. Marmor MF. New hypotheses on the pathogenesis and treatment of serous retinal detachment. Graefes Arch Clin Exp Ophthalmol. 1988;226:548–552.
10. Balaskas K, Guex-Crosier Y, Borruat FX. Indocyanine-green angiography findings in Susac's syndrome. Klin Monatsbl Augenheilkd. 2012;22:426–427.
11. Flammer J, Kaiser H, Haufschild T. Susac syndrome: a vasospastic disorder? Eur J Ophthalmol. 2001;11:175–179.
12. Flammer J, Pache M, Resink TH. Vasospasm, its role in the pathogenesis of diseases with particular reference to the eye. Prog Retin Eye Res. 2001;20:319–349.
13. Prunte C, Flammer J. Choroidal capillary and venous congestion in central serous chorioretinopathy. Am J Ophthalmol. 1996;121:26–34.
14. Artunay O, Senel A, Sengul A, Rasier R, Bahcecioglu H. Central serous chorioretinopathy associated with topical latanoprost therapy. Ocul Immunol Inflamm. 2011;19:453–455.