Overview of Autoimmune Epilepsy

Autoimmune epilepsy is a newly defined group of conditions characterized by recurrent seizures associated with autoimmunity. Cancer and infections are two potential triggers.

Epilepsy is a seizure disorder that causes unprovoked seizures. Seizures can also occur for many reasons other than epilepsy, such as:

• a high fever
• medication side effects
• electrolyte imbalances

Autoimmune epilepsy develops when your immune system attacks healthy brain tissue. The underlying cause is not fully known. Sometimes doctors can detect immune cells, antibodies, or proteins in the cerebrospinal fluid and blood, which help point to or support the diagnosis.

Keep reading to learn more about autoimmune epilepsy, including potential causes, symptoms, and treatments.

Autoimmune epilepsy causes

The underlying cause of epilepsy often cannot be identified. In recent decades, researchers have improved their understanding of how autoimmunity can, on rare occasions, cause brain inflammation, which may lead to seizures. Inflammation in your brain caused by an autoimmune reaction is called autoimmune encephalitis.

The International League Against Epilepsy has recognized autoimmune epilepsy since 2017. In some cases, the trigger of autoimmune epilepsy is not clear, but many different conditions have been associated with its development, including:

• cancer
• diabetes
• polyendocrinopathy (a rare inherited condition in which the body attacks its organs)
• fever
• thyroid disease
• viral infections

Specific types of autoimmune epilepsy include:

• Rasmussen’s syndrome
• anti-NMDA receptor encephalitis
• limbic encephalitis
• GAD65 antibody-related epilepsy

Who’s at risk for autoimmune epilepsy?

In a 2018 study, researchers reported an incidence of autoimmune encephalitis in Olmsted Country, Minnesota, of 0.4 people per 100,000 people per year from 1995 to 2005 and 1.2 people per 100,000 people per year from 2006 to 2015. The increase was likely due to improved recognition. Rates were higher among African Americans than Caucasian Americans.

It’s thought that autoimmune seizures could make up as many as 1 in 7 to 1 in 20 new seizures.

Autoimmune epilepsy symptoms

Some people with autoimmune epilepsy may develop symptoms before their seizures, which can be either part of the seizure itself or as a trigger to the seizure. These include:

• fever
• headaches
• dizziness
• insomnia
• upper respiratory infection

Autoimmune epilepsy often causes:

• seizures that happen several times per day
• focal seizures that only involve one side of your brain
• facial brachial dystonic seizures, which affect one side of the face and an arm on the same side
• seizures that do not respond well to medications
• memory, mood, or behavior changes

Additionally, inflammation may lead to personality changes and psychosis. 

Potential complications of autoimmune epilepsy

Symptoms of autoimmune epilepsy can develop rapidly from the onset of the condition. If not treated with immunotherapy, the seizures can become more frequent, and different seizure types can emerge.

Additionally, epilepsy caused by autoimmune inflammation has a risk of causing seizures that progress to status epilepticus.

Status epilepticus is a seizure that lasts longer than 5 minutes or repeated seizures without a break between them. It can be a life threatening condition. 

When to get medical help

It’s important to seek immediate medical attention any time you or your child develops their first seizure or develops new seizure symptoms.

Medical emergencyCall emergency medical services or go to the nearest emergency room if you or somebody your with has:

• a seizure that lasts longer than 5 minutes
• another seizure shortly after the first
• trouble breathing or waking up after the seizure
• an injury during the seizure.
• a seizure in water

.

How do you test for autoimmune epilepsy?

Tests doctors use to diagnose autoimmune epilepsy include:

• MRI
• electroencephalography (EEG)
• PET
• lumbar puncture (spinal tap) to look for antibodies in the cerebrospinal fluid surrounding your spinal cord and brain
• autoantibody tests using samples of your cerebrospinal fluid and blood
• brain biopsy, in rare cases

Antibodies are immune proteins your immune system produces, and autoantibodies are immune cells that accidentally attack healthy cells in your own body. This may happen if your healthy cells resemble unhealthy cells that the antibodies were intended to attack.

Although testing positive for autoantibodies is highly suggestive of autoimmune epilepsy, they cannot be detected in up to half of people. 

How do you treat autoimmune seizures and epilepsy?

The main treatment for autoimmune epilepsy is a combination of anti-epileptic drugs to stop seizures and immunotherapy to reduce inflammation in your brain. Autoimmune seizures can be difficult to control with antiseizure medications, but once the underlying cause is identified, seizures are often treatable.

The typical immunotherapy treatment involves steroids, such as methylprednisolone or prednisone, given through the bloodstream or orally. You may also receive immunoglobulins to help deactivate the autoimmune reaction.

Some people receive plasma exchange to reduce autoantibodies in the blood. This procedure involves removing a part of your blood called the plasma.

Other immune-suppressing medications you might receive include:

• rituximab (Rituxan)
• tocilizumab (Actemra)
• cyclophosphamide (Cytoxan)
• anakinra (Kineret)
• bortezomib (Velcade, others)
• azathioprine (Imuran, Azasan)
• mycophenolate (CellCept)

Living with autoimmune epilepsy

An early initiation of immunotherapy is associated with a favorable outcome. It may improve your outlook and reduce serious complications.

People with cancer-related autoimmune epilepsy generally have worse outcomes than people who develop autoimmune epilepsy with other underlying causes. 

Can you prevent autoimmune epilepsy?

There are some identified risk factors for autoimmune epilepsy, such as cancer and thyroid disease, but most people who have these risk factors do not develop autoimmune epilepsy.

It’s not known why some people develop this complication, so it’s typically defined as being idiopathic. That means it does not have an identifiable cause. There are no reliable guidelines for preventing it.

Taking general steps to reduce your risk of cancer can potentially reduce your risk. This includes:

• avoiding or quitting smoking to reduce the risk of lung cancer (this can be difficult, but a doctor can build a cessation plan that works for you)
• protecting your skin from the sun
• limiting alcohol consumption
• eating a balanced diet
• maintaining a moderate weight

Takeaway

Autoimmune epilepsy is a group of conditions that cause recurrent seizures due to brain inflammation caused by an autoimmune reaction.

Sometimes the underlying cause is unknown, but it can also be associated with some underlying conditions like cancer or thyroid disease.

It’s important to visit a doctor any time you or your child develop a seizure for the first time or notice new or changing symptoms.

 Source: healthline.com, Heidi Moawad M.D., Daniel Yetman