Autoimmune Encephalitis

What is autoimmune encephalitis?

Autoimmune encephalitis (AE) represents a group of conditions that cause inflammation in your brain. It happens when your immune system mistakenly attacks the proteins of healthy nerve cells and neurotransmitters. This leads to symptoms like memory loss, seizures and psychosis.

What are the symptoms of autoimmune encephalitis?

Autoimmune encephalitis can cause a wide range of symptoms because of the various types. Symptoms typically develop and evolve over weeks to months.

Possible symptoms of AE include:

• Progressive decline in thinking (cognitive) abilities
• Memory issues
• Confusion
• Seizures (which often don’t respond to antiseizure medication)
• Abnormal movements, like repetitive movements of your mouth and face, muscle twitches and an exaggerated startle response
• Issues with using language (aphasia)
• Problems with balance or coordination (ataxia)
• Psychosis, which can involve hallucinations, delusions and paranoia

It’s important to get medical help right away if you develop these symptoms.

What are the possible complications of autoimmune encephalitis?

Complications can include:

• Cognitive impairment
• Prolonged seizures (status epilepticus)
• Coma
• Death

What causes autoimmune encephalitis?

Researchers think autoimmune encephalitis happens when your immune system develops antibodies to specific proteins on the surface of nerve cells or within nerve cells. These antibodies block the necessary protein, causing inflammation.

Like many other autoimmune conditions, researchers don’t know why your immune system attacks healthy cells. In some cases, AE happens alongside cancer. Healthcare providers call this paraneoplastic AE. Other cases are linked to infections, like the herpes simplex virus. But many people have no known trigger for AE.

What are the risk factors for autoimmune encephalitis?

You’re more likely to develop autoimmune encephalitis if you:

• Have had or develop cancer, especially small cell lung cancer, thymoma and ovarian cancer
• Had treatment with immune checkpoint inhibitors (a cancer treatment)
• Had infectious encephalitis

It’s also possible to develop AE without any of these risk factors.

How is autoimmune encephalitis diagnosed?

Healthcare providers diagnose autoimmune encephalitis based on the presence of symptoms in a certain timeframe. They also rely on test results that show inflammation in your brain.

Given the large number of conditions that can look like AE, you may need several tests. Diagnosis can sometimes take many weeks. Tests and exams providers use to diagnose AE include:

• Physical exam and a detailed medical history
• Neurological exam
• Cognitive tests
• Blood tests
• Brain imaging, like a brain MRI
• Spinal tap for cerebrospinal fluid analysis
• Electroencephalogram (EEG)

Your provider may also recommend other tests to rule out other conditions.

How is autoimmune encephalitis treated?

The main treatment goals for autoimmune encephalitis include immunosuppression and tumor removal (if applicable).

First-line therapy works to decrease brain inflammation. It includes:

• Corticosteroids
• IV immunoglobulins
• Plasmapheresis

If this therapy isn’t effective, the next treatment options include:

• Rituximab (a monoclonal antibody injection)
• Cyclophosphamide (a chemotherapy medication)

If you have a tumor, your healthcare team will recommend surgically removing it and/or chemotherapy. This helps speed up the improvement of AE.

Symptom management

You may need additional medications to manage the symptoms of AE, including:

• Antiseizure medications to reduce or prevent seizures
• Medications that manage anxiety and depression, like antidepressants and anxiolytics
• Antipsychotic medications if you’re experiencing psychosis

Physical therapy, occupational therapy and/or speech therapy may also be very helpful to improve your recovery.

How treatable is autoimmune encephalitis?

The effectiveness of treatment for AE varies from case to case. Some people with AE respond very quickly to the first medications they receive — within days. Others will need treatment that lasts for weeks or months.

It can be difficult for healthcare providers to predict how your body will respond to treatment. Know that they’ll carefully monitor your progress and keep you updated.

What is the prognosis for someone with autoimmune encephalitis?

In general, getting treatment early in the course of autoimmune encephalitis tends to decrease your risk of long-term complications and relapse.

But AE affects everyone differently — and other coexisting conditions like cancer may affect your prognosis (outlook). Your healthcare team will be able to give you a better idea of what to expect.

Is autoimmune encephalitis lifelong?

Autoimmune encephalitis generally responds well to treatment and goes away. But this can take a long time for some people. AE can also relapse (come back), especially if you have cancer that’s not responding to treatment.