What is Susacs syndrome

TL;DR: Susac's syndrome is a rare, immune-mediated condition characterized by a clinical triad of brain dysfunction (encephalopathy), visual disturbances (retinal artery occlusions), and hearing loss. It occurs when the body’s immune system mistakenly attacks the tiny blood vessels (arterioles) in the brain, retina, and inner ear, leading to tissue damage from restricted blood flow.

What exactly is Susac's syndrome?

Susac's syndrome is a rare vasculopathy, meaning it is a disorder affecting the blood vessels. Specifically, it involves the microvessels—the smallest branches of the circulatory system. When these vessels become inflamed, they cannot deliver oxygen effectively to vital tissues. For individuals living with Susac's syndrome, this results in a distinctive clinical triad: encephalopathy (confusion, memory loss, or personality changes), branch retinal artery occlusions (which cause blind spots or vision loss), and sensorineural hearing loss. At DiseaseMaps.org, 20 community members have connected to share their experiences with this challenging diagnosis.

Which body systems are affected by Susac's syndrome?

Because Susac's syndrome affects microvessels, it primarily targets three specific areas of the body:

• The Brain: Inflammation often manifests as cognitive impairment, headaches, or even seizures.


• The Eyes: Blockages in the retinal arteries can lead to permanent or temporary vision loss, often described as "curtains" or dark spots in the visual field.


• The Inner Ear: Damage to the cochlear microvasculature frequently results in hearing loss, which may be sudden or progressive, often accompanied by tinnitus or vertigo.

Who is typically affected by Susac's syndrome?

Susac's syndrome is exceptionally rare, with fewer than 500 cases reported in medical literature globally. It most frequently affects women between the ages of 20 and 40, though it can occur in men and across a wider age range. Because the symptoms are often attributed to other conditions like multiple sclerosis or lupus, Susac's syndrome is frequently misdiagnosed, leading to a significant delay in receiving appropriate immunosuppressive therapy.

What is the underlying mechanism of the disease?

The exact cause of Susac's syndrome remains unknown, but it is classified as an autoimmune endotheliopathy. This means the immune system develops antibodies that target and damage the endothelial cells that line the inner surface of the arterioles. This damage causes the vessels to thicken and narrow, essentially "choking off" blood flow to the brain, retina, and inner ear. Unlike some other inflammatory conditions, this process is usually self-limiting but can cause permanent damage if not treated aggressively during the active phase.

How is Susac's syndrome differentiated from other conditions?

Distinguishing Susac's syndrome from multiple sclerosis (MS) is critical. While both can show lesions on an MRI, the location of these lesions differs. In Susac's syndrome, MRI scans often reveal characteristic "snowball" lesions in the center of the corpus callosum—a specific area of the brain—which is rarely seen in MS. Furthermore, the presence of retinal artery occlusions (confirmed by a specialized eye exam called fluorescein angiography) is a hallmark feature that helps clinicians confirm the diagnosis.

Next steps

• Consult a neurologist or neuro-ophthalmologist who has experience with rare vasculitis or autoimmune disorders.


• Request a fluorescein angiography and a high-resolution brain MRI to evaluate for hallmark clinical signs.


• Connect with the 20 members of the DiseaseMaps.org community to share experiences and coping strategies.


• Seek early evaluation for immunosuppressive treatments, such as corticosteroids or IVIG, to prevent permanent tissue damage.

Medical disclaimer: This content is for educational purposes only and does not constitute professional medical advice, diagnosis, or treatment; always seek the advice of your physician regarding a medical condition.

References

• National Institutes of Health (NIH) Genetic and Rare Diseases (GARD) Information Center.


• Orphanet: Portal for rare diseases and orphan drugs.


• Online Mendelian Inheritance in Man (OMIM) database.


• American Academy of Neurology (AAN) clinical literature on autoimmune vasculopathies.