Autoimmune Epilepsy

Autoimmune epilepsy is a type of epilepsy in which seizures are caused by the immune system mistakenly attacking brain cells. It can occur alongside conditions affecting the immune system, particularly autoimmune encephalitis.

This condition is also referred to as autoimmune associated epilepsy or acute symptomatic seizures secondary to autoimmune encephalitis. Antibodies, which usually protect the body from infections, target receptors in the brain, causing inflammation and seizures.

Seizures in autoimmune epilepsy often do not respond well to standard antiseizure medicines. Immunotherapy is usually required to reduce the immune response and brain inflammation. Early treatment can improve seizures, sometimes stopping them entirely, although some people may continue to experience seizures even after treatment.

Symptoms

Symptoms may appear after an illness with fever and often include sudden, serious seizures. Types of seizures include:

• Focal seizures, which are the most common and may cause changes or loss of awareness. Symptoms depend on the brain region affected and can include body shaking, déjà vu, nausea, or visual disturbances such as flashing lights

• Faciobrachial dystonic seizures, causing muscle contractions on one side of the face and in the arm on the same side

Other seizure-related symptoms:

• Multiple seizures per day

• Seizures resistant to antiseizure medicines

• Seizures lasting more than five minutes or occurring close together without regaining consciousness (status epilepticus)

Additional symptoms may include:

• Memory loss and cognitive difficulties

• Personality and behavior changes

• Involuntary or clumsy movements

• Irregular eye movements

• Changes in heart rate, blood pressure, and other autonomic functions

When to see a doctor

Seek emergency care if a seizure lasts more than five minutes or occurs repeatedly with loss of consciousness. Also seek immediate care for high fevers or difficulty breathing. Contact a healthcare professional promptly if you experience a first-time seizure or other symptoms of autoimmune epilepsy.

Causes

Autoimmune epilepsy occurs when the immune system attacks brain cells, causing seizures. The immune system’s antibodies, which normally protect against infection, mistakenly target healthy brain cells.

Common causes include:

• Autoimmune encephalitis, the most frequent cause, where antibodies target receptors such as NMDA, LGI1, CASPR2, or GAD65

• Rasmussen syndrome, in which T cells cause brain inflammation and damage, leading to persistent seizures

• Cancer, which may trigger a paraneoplastic syndrome causing the immune system to attack brain cells

Risk factors

Although autoimmune epilepsy is rare, it can affect both adults and children. Risk factors include:

• Having another autoimmune disease, such as rheumatoid arthritis, Graves’ disease, Hashimoto thyroiditis, Crohn’s disease, ulcerative colitis, or lupus

• History of cancer

• Family history of autoimmune disease in a parent, sibling, or child

Complications

Complications may include:

• Status epilepticus, prolonged or repeated seizures with unconsciousness, requiring emergency care

• Seizures that do not respond to treatment

Prevention

Autoimmune epilepsy may not be preventable. However, early cancer detection and treatment may help prevent autoimmune encephalitis triggered by tumors, which can lead to epilepsy. Consult a healthcare professional about cancer risk and recommended screenings.