Susac's syndrome

A rare autoimmune disease affecting the brain, retina, and inner ear

Susac's syndrome is a rare autoimmune disease characterized by a clinical triad of encephalopathy, branch retinal artery occlusion, and sensorineural hearing loss. It primarily affects young women and is believed to be caused by an autoimmune response that leads to microvascular occlusion in the brain, retina, and inner ear.

Pathophysiology

Susac's syndrome is thought to be an autoimmune endotheliopathy, where the body's immune system mistakenly attacks the endothelial cells lining the small blood vessels in the brain, retina, and inner ear. This results in microinfarctions and subsequent damage to these tissues. The exact antigen or trigger for this autoimmune response is not well understood.

Clinical Presentation

The classic triad of symptoms in Susac's syndrome includes:

• Encephalopathy: Patients may experience headaches, confusion, memory loss, and other cognitive disturbances. Behavioral changes and psychiatric symptoms can also occur.
• Branch retinal artery occlusion: This leads to visual disturbances, such as scotomas or vision loss, due to the occlusion of small arteries in the retina.
• Sensorineural hearing loss: Hearing loss is typically bilateral and may be accompanied by tinnitus or vertigo.

Microangiopathy in Susac's syndrome as seen in retinal imaging.

Diagnosis

Diagnosis of Susac's syndrome is based on clinical findings, imaging studies, and exclusion of other conditions. Magnetic resonance imaging (MRI) of the brain often shows characteristic lesions in the corpus callosum and other areas. Fluorescein angiography of the retina can reveal branch retinal artery occlusions. Audiometry is used to assess hearing loss.

Treatment

Treatment of Susac's syndrome involves immunosuppressive therapy to reduce the autoimmune attack on the endothelium. Common treatments include high-dose corticosteroids, intravenous immunoglobulin (IVIG), and other immunosuppressive agents such as mycophenolate mofetil or rituximab. Early and aggressive treatment is important to prevent permanent damage.

Prognosis

The prognosis of Susac's syndrome varies. Some patients experience a monophasic illness with complete recovery, while others may have a relapsing-remitting course or chronic symptoms. Early diagnosis and treatment improve outcomes.

Related pages

• Autoimmune disease
• Encephalopathy
• Retinal artery occlusion
• Sensorineural hearing loss