Autoimmune encephalitis is an uncommon and complex condition that can cause significant changes in both mental and physical health. It is a collection of related conditions in which the body’s immune system attacks the brain, causing inflammation. The immune system produces substances called antibodies that mistakenly attack brain cells. The disease can be progressive (worsening over time) or relapsing-remitting (with alternating flare-ups and periods of recovery)If left untreated, autoimmune encephalitis can quickly become serious. It may lead to coma or permanent brain injury. In rare cases, it can be fatal.
Who gets autoimmune encephalitis?
Autoimmune encephalitis was once considered rare, but with the advent of better diagnostics and enhanced knowledge about the condition, it has been diagnosed more frequently now then previously.
Factors that affect risk include:
- Gender: This illness, like many autoimmune diseases, affects women more often than men.
- Age: It can happen at any age but is diagnosed most often in young women.
- Family history: It does not appear to run in families.
What causes autoimmune encephalitis?
In many cases, the cause of autoimmune encephalitis is unknown. But experts say it can be caused by:
- Exposure to certain bacteria and viruses, including streptococcus and herpes simplex virus.
- A type of tumor called a teratoma, generally in the ovaries, that causes the immune system to produce specific antibodies.
- Rarely, some cancers that can trigger an autoimmune response (when the immune system attacks the body’s own tissues).
Symptoms of autoimmune encephalitis
The early stages of autoimmune encephalitis (AE) vary from person to person. Some people rapidly develop new or changing symptoms, others may develop fluctuating symptoms.
Neurologic symptoms
- Problems with memory and the process of thinking (also known as cognition)
- Abnormal movements
- Seizures
- Problems with balance or coordination (or ataxia)
- Having trouble speaking
- Changes in vision
- Loss of consciousness or coma
Psychiatric symptoms
- Hallucinations, delusions, or paranoia (or psychosis)
- Aggressive behaviour
- Inappropriate sexual behaviour
Diagnosing autoimmune encephalitis
Autoimmune encephalitis can be difficult to diagnose. Because it has been considered rare, doctors can mistake it for a mental health disorder or drug abuse. At the same time, early diagnosis is important to avoid serious complications.
Tests may include:
- A spinal tap (lumbar puncture) to withdraw a sample of cerebrospinal fluid, the liquid that surrounds your brain and spinal cord. The fluid can be examined for signs of autoimmune encephalitis or another disease.
- Blood tests to look for antibodies that may indicate autoimmune encephalitis.
- MRI (magnetic resonance imaging) scans of your brain to identify signs of the disease.
Generally, a diagnosis of autoimmune encephalitis requires three conditions:
- Short-term memory loss, psychiatric symptoms or other symptoms of an altered mental state all within three months of one another
- At least one of the following:
- Numbness, weakness or paralysis that affects a specific limb or area of the body
- Seizures that can’t be explained by other conditions
- A high white blood cell count in the cerebrospinal fluid
- MRI brain that shows signs of inflammation
- Ruling out other causes
Treatment for autoimmune encephalitis
Early treatment can greatly reduce symptoms and reduce the chances of long-term complications.
Treatments may include:
- Steroids to reduce brain inflammation and the immune system’s response
- Intravenous immunoglobulin (IVIG), given in an IV drip, to introduce antibodies from the plasma of healthy donors. IVIG removes harmful antibodies and reduces inflammation.
- Plasma exchange (removal and replacement of the liquid part of the blood) to take out harmful antibodies
- Surgery to remove a teratoma.
- Immunosuppressant medications, if other treatments are not effective.