Susac syndrome

Introduction:

Susac syndrome was first described by Susac etal in 1979. This syndrome is characterised by rapidly progressing encephalopathy, blindness and hearing loss.

Pathophysiology:

This is actually an endotheliopathy affecting precapillary arterioles. This endotheliopathy could probably be immune mediated. This causes rapid tissue infarction which leads to these problems.

Women are commonly affected than men. Typical vulnerable age group is between 20 – 40.

Clinical features:

1. Severe head ache
2. Rapid dementia
3. Micro infarcts seen in corpus callosum demonstrable in MRI scans
4. Photopsia and black spots due to retinal artery occlusion
5. Scintillating scotoma
6. Rapidly progressive sensori neural hearing loss on both sides
7. Vertigo
8. Nystagmus

Management:

High dose steroid therapy is the main treatment modality.

Intravenous administration of immunoglobulin.

Cyclophosphamide administration.

Rituximab is the currently used drug in the management. This is a monclonal antibody against CD20 protein. This receptor protein is found on the surface of B lymphocytes.