Diagnosis, differential diagnosis and misdiagnosis of Susac syndrome

James D. Triplett, Jessica Qiu, Billy O'Brien, Sumana Gopinath, Benjamin Trewin, Penelope J. Spring, Mohamed Shaffi, Jerome Ip, Fiona Chan, Luke Chen, Ian Wilson, Claire Muller, Heidi N. Beadnall, Mike Boggild, Anneke Van der Walt, Richard Roxburgh, Nabil Seery, Tomas Kalincik, Michael H. Barnett, John D.E. ParrattStephen W Reddel, Benjamin Tsang, Todd A. Hardy

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15 Citations (Scopus)


Background and purpose: Susac syndrome (SuS) is an inflammatory condition of the brain, eye and ear. Diagnosis can be challenging, and misdiagnosis is common. Methods: This is a retrospective review of the medical records of 32 adult patients from an Australasian cohort of SuS patients. Results: An alternative diagnosis prior to SuS was made in 30 patients (94%) with seven patients receiving two or more diagnoses. The median time to diagnosis of SuS was 3 months (range 0.5–100 months). The commonest misdiagnoses were migraine in 10 patients (31%), cerebral vasculitis in six (19%), multiple sclerosis in five (16%) and stroke in five (16%). Twenty-two patients were treated for alternative diagnoses, 10 of whom had further clinical manifestations prior to SuS diagnosis. At presentation seven patients (22%) met criteria for definite SuS, 19 (59%) for probable SuS and six (19%) for possible SuS. Six patients (19%) presented with brain–eye–ear involvement, 14 with brain–ear (44%), six with brain–eye (19%) and six (19%) with only brain involvement. In patients with the complete triad of symptoms the median delay to diagnosis was 3 months (range 1–9 months) compared to 5.25 months (range 0.5–100 months) for patients with encephalopathy and ocular symptoms at presentation. Conclusions: Susac syndrome patients are frequently misdiagnosed at initial presentation, despite many having symptoms or radiological features that are red flags for the diagnosis. Delayed diagnosis can lead to patient morbidity. The varied ways in which SuS can present, and clinician failure to consider or recognize SuS, appear to be the main factors leading to misdiagnosis.

Original languageEnglish
Pages (from-to)1771-1781
Number of pages11
JournalEuropean Journal of Neurology
Issue number6
Publication statusPublished - Jun 2022


  • brain–eye–ear
  • migraine
  • multiple sclerosis
  • retinocochleocerebral vasculopathy
  • Susac syndrome

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