• rare microangiopathy affecting the arteries of the brain, retina, and cochlea (retino-cochleo-cerebral dysimmune vasculopathy)
    • in partial forms of this syndrome, only 2 of 3 components are clinically apparent. There are reports of subacute bilateral sensorineural hearing loss with bilateral retinal artery occlusion without obvious cerebral dysfunction
  • described by John Susac in 1979 (but the first reported in 1973)  (Pfaffenbach, 1973)
  • predominantly affects women (3:1) in the 2nd-4th decade (range 7-72 years), often associated with childbirth
  • the exact cause is unknown; autoimmune microangiopathy or autoimmune coagulopathy (with APL positivity) are considered (Bucciarelli, 2014)
    • different pathogenetic mechanisms may also cause the same clinical syndrome

Clinical presentation

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Diagnostic evaluation

Brain imaging (MRI)

  • leukoencephalopathy, mostly supratentorial with a tendency to involve the central corpus callosum
  • microinfarcts in the internal capsule – “string of pearls
  • specific lesions in the corpus callosum – “snowball lesions
  • grey matter involvement and leptomeningeal enhancement may be present (in approx. 30%)
    • such findings are useful in the DDx of MS and ADEM
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Ophthalmological examination

  • widefield fluorescein angiogram can show artery occlusion
    • often peripheral branch retinal artery occlusions – BRAOs
    • segmental vessel wall increased fluorescence/leakage, capillary dropout, peripheral nonperfusion, and peripheral capillary changes
  • search for signs of uveitis

Laboratory tests

  • CSF
    • oligoclonal bands are commonly absent
    • sporadic lymphocytic pleocytosis or hyperproteinorhachia
  • CBC: occasional monocytosis or eosinophilia
  • mild elevation of serum antinuclear and/or antiphospholipid antibodies

Diagnostic criteria

Suspected Incomplete Complete
1 symptom 2 symptoms complete clinical triad (approx 13%)
absence of significant vascular risk factors (atherosclerosis and/or coagulopathy)
+ one of the following risk factors:

  • female between 20-40 years of age
  • female within 1 year of pregnancy
  • presence of characteristic corpus callosum or periventricular lesions on MR

Differential diagnosis

  • demyelinating diseases
    • multiple sclerosis (MS)
    • NMO
    • ADEM
  • multi-infarct disorders
  • other autoimmune diseases
    • antiphospholipid syndrome
    • Behçet’s disease
    • Takayasu’s disease
    • Wegener’s granulomatosis
    • systemic lupus erythematosus (SLE)
    • sarcoidosis
    • Sjogren’s syndrome
  • infections
    • Creutzfeldt Jakob disease
    • Lyme borreliosis
    • viral encephalitis
    • syphilis
    • Progressive Multifocal Leukoencephalopathy (PML)
  • malignancy or paraneoplastic syndrome


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Susac syndrome
link: https://www.stroke-manual.com/susac-syndrome/