Susac Syndrome

• Young patient
• Elevated csf protein levels
• Numerous T2 lesions in white AND grey matter. These lesions may enhance
• Corpus Callosum is always affected
• Diagnostic triad comprises of BRAO (Branch Retinal Artery Occlusions), Encephalopathy and Hearing loss.

Clinical presentation:

Subacute encephalopathy

1. Headaches
2. Personality changes
3. Impaired cognition
4. Ataxia
5. Dysarthria

Ophthalmic

1. Segmental loss of vision
2. Retinal fluoroscein angiography shows peripheral arteriolar occlusion. Gass plaques are seen (these are located away from bifurcations). Arteriolar hyperfluoroscence is seen which indicates active disease.

Hearing loss

1. Acute
2. Uni or bilateral
3. Sensorineural in type, and is asymmetical. This is due to microinfarcts affecting the apical cochleae. Audiometry shows that lower frequencies are mostly affected.

Treatment:

• Methylprednisolone 1 gm IV once daily for 5 days followed by Prednisone 80 mg daily for a month, followed by slow taper. While Prednisone is being tapered, additional immunosuppresant therapy has to be initiated with Imuran. Immunosuppression will need to be maintained for around 2 years.
• Vision loss treated with Hyperbaric Oxygen. (100% oxygen at 6 atmos pressure in a hyperbaric chamber)
• Aspirin is added for prevention of infarcts.
• IVIG has also been used in an acute setting in addition to the above.
• Aggressive treatment is warranted because the disease is short lived and self limiting, but the neurological damage persists.