Wednesday, October 03, 2007

Susac Syndrome-- Pearls

Triad of BRAO (branch retinal artery occlusion), hearing loss, encephalopathy

Demographic age9-70 predominantly young adults 2:1 female

BRAO vision spots, loss eye exam-- infarctions, BRAO, Gass plaques and silver lines. Gass plaques are like Hollenhorst plaques but not necessarily at branch points. Clinical variable-- spots, visual obscurations, blurring, inversion of vision transient. Diagnostic test of choice-- fluorescein angiogram, signature finding in young adult esp.

Hearing loss-- affects apex of cochlea first, low tone hearing loss. Bang bang is one ear then other, rare in MS. If affects semicircular canal may cause vertigo, tinnitus, vomiting,confusion with Meniere's disease

Encephalopathy-- usually strong association with headache. May persist.

MRI callosal lesions "snowball" and "spokes" often in center of corpus callosum rather than on ventricular edge, holes in middle of lesions virtually pathognomonic per Susac. May also have lesions in brain substance and meninges, may enhance. Cranial nerves are spared. Cases may even mimic cancer.

Pathology-- vasculopathy not vasculitis. Small arteriolar occlusion. Inflammation afterwards may mimic encephalitis pathologically. Question of relation to juvenile dermatomyositis, rash, looks like erythema nodosum.

Course-- two types: two year type and long term type.

Therapy-- Big sledgehammer and little sledgehammer. protocols in J Neurol Sci? 2007. Include initial Solumedrol and IVIG then Cell Cept, or cytoxan or rituxan.

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