Understanding Rare Neurological Diseases: Susac's Syndrome

Health & Medical Blog

Susac's syndrome (SS) is most often described as a rare autoimmune neurological condition. It is easy to misdiagnose as multiple sclerosis (MS) due to some similarities in symptoms. With increased understanding and improved differentiation between SS and similar conditions, some of the symptoms associated with SS can be minimized or prevented.

Triad Of Symptoms

What differentiates SS from MS or similar neurological conditions is a specific triad of symptoms. These include encephalopathy, which is a brain dysfunction that can take many forms and is seen in various neurological disorders. Encephalopathy can cause any number of symptoms depending on the region of the brain that is affected and the severity of damage. Problems with speech, gait, and vision may be symptoms. Additionally, psychological and behavioral changes may also occur.

The next in the symptom triad is occlusion (blockage) of the retinal arteries. The severity of vision loss may depend on the exact location of the blockage. For example, if branches of the retinal arteries are affected, vision loss may be less dramatic than if problems occur in the central artery. When the central retinal artery is blocked, vision loss is quick and permanent.

The last symptom in the triad is hearing loss. The hearing loss associated with SS is sensorineural, meaning it is caused by damage to auditory nerve and/or other nervous system pathways responsible for hearing. Unfortunately, this form of hearing loss is permanent, but can be lessened if there is an underlying disease process that can be successfully controlled.

Diagnostic Problems

One problem that makes SS difficult to diagnose is the hallmark symptoms may not occur simultaneously until the disease has progressed. This can lead to misdiagnosis since any symptom alone can be misinterpreted as a single problem. An important tool for diagnosing SS and the differential diagnosis of the condition is the use of MRI. Most brain lesions found in SS are usually located in the central area of the corpus callosum. Conversely, brain scans of MS patients typically reveal brain lesions that mostly spare the corpus callosum.

Treatment Options

SS rarely causes major complications, but may cause significant impairments in some people with a severe course of disease. Since SS is autoimmune, the appropriate course of treatment includes immunosuppressive medications. For most people, SS causes flare-ups of the disease with periods of remission. Immunosuppressive medications may reduce the number of flare-ups and additional medications, such as steroids, may be used to shorten the duration and intensity of flares.

SS is a rare condition, which can make it harder to diagnose in the early stages. With increasing recognition of the condition and ways to distinguish it from other degenerative neurological conditions, those affected can look forward to a better prognosis and treatment.


7 September 2016