title: Clinical features, diagnostic findings, and treatment of Susac syndrome: a case series.
abstract: BACKGROUND
  Susac syndrome (SS) is a rare, presumed autoimmune condition characterized by the clinical triad of branch retinal artery occlusions (BRAOs), encephalopathy, and sensorineural hearing loss. The aim of this study was to evaluate clinical features, diagnostic results, treatment, and outcomes in SS.
  
  
  METHODS
  Five patients with SS were referred to three tertiary care centers in Boston. The observation period across these patients was 7-57months.
  
  
  RESULTS
  At initial presentation, none of the patients demonstrated the complete triad of BRAO, sensorineural hearing loss, and encephalopathy. The interval between symptom onset and diagnosis of SS was 4-30weeks. Brain MRI findings thought to be characteristic of SS (including callosal fluid-attenuated inversion recovery (FLAIR) hyperintense and T1 hypointense lesions) were frequently absent. Microinfarcts noted on diffusion-weighted imaging (DWI), BRAOs and vessel wall hyperfluorescence on fluorescein angiography (FA) were present in all cases in the acute encephalopathic phase. All patients treated with glucocorticoids and intravenous immunoglobulins (IVIg) alone experienced further clinical progression until additional immunosuppressive therapy was instituted.
  
  
  CONCLUSIONS
  The rarity of SS, its incomplete and variable presentation, and the nonspecific imaging findings invariably led to delayed diagnosis. DWI and FA should be used to identify the acute microvascular injury and monitor treatment response. Immunomodulatory agents more potent than glucocorticoids and IVIg might be required to control the disease.
authors.affiliation: Harvard Medical School, Boston, MA, United States; Massachusetts General Hospital, Department of Neurology, 15 Parkman Street, Boston, MA 02114, United States; Massachusetts Eye and Ear Infirmary, Neuro-Ophthalmology Service, 243 Charles St., Boston, MA 02114, United States. Electronic address: ivodopivec@partners.org.
authors.forename: Ivana
authors.initials: I
authors.lastname: Vodopivec
authors.affiliation: Harvard Medical School, Boston, MA, United States; Brigham and Women's Hospital, Department of Neurology, 75 Francis Street, Boston, MA 02115, United States.
authors.forename: Nagagopal
authors.initials: N
authors.lastname: Venna
authors.affiliation: Harvard Medical School, Boston, MA, United States; Massachusetts Eye and Ear Infirmary, Neuro-Ophthalmology Service, 243 Charles St., Boston, MA 02114, United States.
authors.forename: Joseph F
authors.initials: JF
authors.lastname: Rizzo
authors.affiliation: Harvard Medical School, Boston, MA, United States; Brigham and Women's Hospital, Department of Neurology, 75 Francis Street, Boston, MA 02115, United States.
authors.forename: Sashank
authors.initials: S
authors.lastname: Prasad
mesh_terms: D000328:Adult; D001921:Brain / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D005451:Fluorescein Angiography; D005938:Glucocorticoids / Q000627:therapeutic use*; D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000627:therapeutic use*; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D055955:Susac Syndrome / Q000175:diagnosis* / Q000188:drug therapy* / Q000473:pathology; D063189:Symptom Assessment; D055815:Young Adult
chemical_list: D005938:Glucocorticoids; D016756:Immunoglobulins, Intravenous; D007166:Immunosuppressive Agents
keywords: Branch retinal artery occlusion; Encephalopathy; Fluorescein angiography; Hearing loss; MRI; Susac syndrome; Visual impairment