Susac’s Syndrome: Confusion, Expressive Aphasia, Gait Instability

Initial treatment includes aggressive immunosuppression, primarily with high-dose corticosteroids and often with intravenous immunoglobulins (IVIg). Cyclophosphamide, mycophenolate mofetil, methotrexate, and azathioprine have also been used.¹¹ After an initial pulse of corticosteroids, approximately one to three years of immunosuppression is recommended with prednisone and a steroid-sparing agent such as azathioprine.^11,16 Data on use of antiplatelet agents is mixed.^6,16 To date, there is one study that examines long-term outcomes in nine patients over a mean of 6.4 years.⁷ Corticosteroids were found to effectively treat encephalopathy with relapses as the dose was tapered. However, corticosteroids did not improve hearing loss or the development of new retinal artery occlusions.⁷

Our patient received methylprednisolone, 1 gram daily for five days and IVIg (400 mg/kg) daily for five days, followed by 60 milligrams of prednisone daily. Aspirin 81 milligrams daily was started. During the course of his initial treatment, he demonstrated significant neurologic improvement with decreased word-finding difficulties, steadier gait, and improved memory. His visual acuity is intact; however, he continues to suffer from right-sided hearing loss.

The Bottom Line

Susac’s syndrome is a microangiopathy characterized by encephalopathy, sensorineural hearing loss, branch retinal artery occlusions, and specific MRI findings, notably multifocal hyperintensities with involvement of the central fibers of the corpus callosum.

The differential diagnosis for patients with Susac’s syndrome is broad and includes primary angiitis of the CNS, infections, multiple sclerosis, and systemic rheumatologic diseases.

Treatment of Susac’s syndrome involves aggressive immunosuppression with high-dose corticosteroids, and depending on the severity of the manifestations, intravenous immunoglobulin and/or cyclophosphamide. Immunosuppression should be prolonged, and a steroid-sparing agent should be added, given the potential for disease relapse.

Dr. Feldman is a rheumatology fellow at Brigham and Women’s Hospital and Beth Israel Deaconess Medical Center, both in Boston. Dr. Kane-Wanger is a member of the rheumatology faculty of the Beth Israel Deaconess Medical Center.

References

1. Hanley DF, Johnson RT, Whitley RJ. Yes, brain biopsy should be a prerequisite for herpes simplex encephalitis treatment. Arch Neurol. 1987;44:1289-1290.
2. Steiner I, Budka H, Chaudhuri A, et al. Viral encephalitis: A review of diagnostic methods and guidelines for management. Eur J Neurol. 2005;12:331-343.
3. Boesenberg C, Schulz-Schaeffer WJ, Meissner B, et al. Clinical course in young patients with sporadic Creutzfeldt-Jakob disease. Ann Neurol. 2005;58:533-543.
4. Calabrese LH, Duna GF, Lie JT. Vasculitis in the central nervous system. Arthritis Rheum. 1997;40:1189-1201.
5. Susac JO, Hardman JM, Selhorst JB. Microangiopathy of the brain and retina. Neurology. 1979;29:313-316.
6. Susac JO. Susac’s syndrome: The triad of microangiopathy of the brain and retina with hearing loss in young women. Neurology. 1994;44:591-593.
7. Aubart-Cohen F, Klein I, Alexandra JF, et al. Long-term outcome in Susac syndrome. Medicine. 2007;86:93-102.
8. Nicolle MW, McLachlan RS. Microangiopathy with retinopathy, encephalopathy, and deafness (RED-M) and systemic features. Semin Arthritis Rheum. 1991;21:123-128.
9. Do TH, Fisch C, Evoy F. Susac syndrome: Report of four cases and review of the literature. AJNR Am J Neuroradiol. 2004;25:382-388.
10. Petty GW, Engel AG, Younge BR, et al. Retinocochleocerebral vasculopathy. Medicine. 1998;77:12-40.
11. Bienfang DC, McKenna MJ, Papaliodis GN, Gonzalez RG, Stemmer-Rachamimov A. Case records of the Massachusetts General Hospital. Case 24-2011. A 36-year-old man with headache, memory loss, and confusion. N Engl J Med. 2011;365:549-559.
12. Bogousslavsky J, Gaio JM, Caplan LR, et al. Encephalopathy, deafness and blindness in young women: A distinct retinocochleocerebral arteriolopathy? J Neurol Neurosurg Psychiatry. 1989;52:43-46.
13. Heiskala H, Somer H, Kovanen J, Poutiainen E, Karli H, Haltia M. Microangiopathy with encephalopathy, hearing loss and retinal arteriolar occlusions: Two new cases. J Neurol Sci. 1988;86:239-250.
14. 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.
15. White ML, Zhang Y, Smoker WR. Evolution of lesions in Susac syndrome at serial MR imaging with diffusion-weighted imaging and apparent diffusion coefficient values. AJNR Am J Neuroradiol. 2004;25:706-713.
16. Garcia-Carrasco M, Jimenez-Hernandez C, Jimenez-Hernandez M, et al. Susac’s syndrome: An update. Autoimmun Rev. 2011;10:548-552.
17. McLeod DS, Ying HS, McLeod CA, et al. Retinal and optic nerve head pathology in Susac’s syndrome. Ophthalmology. 2011;118:548-552.
18. Roeser MM, Driscoll CL, Shallop JK, Gifford RH, Kasperbauer JL, Gluth MB. Susac syndrome—a report of cochlear implantation and review of otologic manifestations in twenty-three patients. Otol Neurotol. 2009;30:34-40.
19. Demir MK. Case 142: Susac syndrome. Radiology. 2009;250:598-602.