Autoimmune Encephalitis

Diagnosis

Autoimmune encephalitis diagnosis involves a review of your symptoms, a physical exam and several tests. It’s important to get an accurate diagnosis because autoimmune encephalitis, also known as AE, can be mistaken for other diseases.

Experts have created autoimmune encephalitis criteria to help healthcare professionals diagnose people with AE. Healthcare professionals look for patterns of symptoms that signal AE. They also test for signs that antibodies are attacking receptors in the brain to cause AE.

Tests also help rule out other possible causes of your symptoms, such as infections or other autoimmune conditions.

Sometimes people are incorrectly diagnosed with autoimmune encephalitis. It’s important for healthcare professionals to consider all potential conditions when making a diagnosis.

Lab tests

Testing for autoimmune encephalitis includes checking for antibodies. AE is caused by antibodies in the brain that attack proteins and receptors in the brain and cause symptoms.

Some tests may be done on your blood. Other tests are done on the fluid that surrounds your brain and spinal cord, known as cerebrospinal fluid. Cerebrospinal fluid is removed using a procedure known as a lumbar puncture. During the procedure, a healthcare professional numbs the lower back and uses a hollow needle to remove cerebrospinal fluid for testing.

Brain imaging

Your healthcare professional also may recommend an MRI of your brain. MRIs can look for signs of autoimmune encephalitis or rule out other causes of your symptoms.

Other imaging tests may look for signs of cancer that may have triggered AE.

EEG

An electroencephalogram, also known as an EEG, tests the electrical activity in your brain. It may show seizure activity and may help your healthcare professional diagnose AE. An EEG also can help rule out other conditions.

Treatment

Autoimmune encephalitis treatment focuses on the immune system, which is mistakenly attacking brain cells. If a tumor is causing autoimmune encephalitis, the first step is to diagnose and treat the tumor.

Medicines

Immunotherapy works by reducing the immune system’s activity and improving inflammation.

Two types of immunotherapy are given through an IV in a vein in the arm. Most people get this therapy in a hospital. Medicines include:

• Methylprednisolone (Solu-Medrol). This high-dose steroid is given daily for 3 to 7 days.
• Immunoglobulin (IVIg). This medicine may be given daily for 2 to 5 days.

Other treatment options include:

• Oral corticosteroids. With this medicine, you start with a larger dose and then slowly lower the dose over weeks to months, known as tapering.
• Plasma exchange. This therapy gets rid of antibodies that are causing the immune system to attack brain cells. During plasma exchange, the liquid part of your blood is removed and separated from your blood cells. The blood cells are put back into your body and your body makes more plasma.

If your symptoms respond to immunotherapy, the medicine doses are slowly lowered over time, known as tapering. You may take an oral corticosteroid at a lower dose for several weeks. Or you may get monthly doses of methylprednisolone or immunoglobulin through an IV for several months.

If your symptoms aren’t improving, your healthcare professional also may recommend the medicines rituximab (Rituxan, Truxima, others), cyclophosphamide or tocilizumab (Actemra, Tofidence, Tyenne). These medicines can improve symptoms and help lower the chances of AE coming back.

Most people recover with treatment. The earlier you receive treatment, the more quickly you may recover. Early treatment also lowers the chances of having lasting symptoms due to AE or having another bout of autoimmune encephalitis.

Therapies

You may need treatment for complications, such as epilepsy, sleep conditions and trouble with movements. You also may need rehabilitation if AE affected your memory, thinking skills or speech. Occupational and speech therapists, along with mental health professionals and other specialists, can help in your recovery.

If cancer triggered autoimmune encephalitis, you’re treated for the cancer and monitored to check if the cancer comes back. Sometimes people with other symptoms related to AE need to get regular care from specialists.

The long-term outlook can vary from person to person. Full recovery may take months or years. Many people continue to have symptoms related to thinking and behavior for longer than a year. But treatment continues to improve symptoms for 18 months to two years.

Some people fully recover while others may have lasting symptoms that are mild or more serious. Getting treated early helps improve your long-term outlook.

People who have recovered from certain types of autoimmune encephalitis, such as anti-NMDA receptor encephalitis and anti-LGI1 encephalitis, are at risk of symptoms coming back. Sometimes symptoms return after several years.