What are the other Names for this Condition? (Also known as/Synonyms)

• Autoimmune Encephalopathy

What is Autoimmune Encephalitis? (Definition/Background Information)

• Autoimmune Encephalitis refers to a group of conditions that occur when the body's immune system mistakenly attacks healthy brain cells, leading to inflammation of the brain
• People with Autoimmune Encephalitis may have various neurologic and/or psychiatric symptoms
  • Neurologic symptoms may include impaired memory and cognition, abnormal movements, seizures, and/or problems with balance, speech, or vision
  • Psychiatric symptoms may include psychosis, aggression, inappropriate sexual behaviors, panic attacks, compulsive behaviors, euphoria or fear
• The symptoms may fluctuate, but often progress over days to a few weeks. Symptoms can progress to loss of consciousness or even coma
• Autoimmune Encephalitis may be associated with antibodies to proteins on the surface of nerve cells, or within nerve cells. Some of these proteins are involved in passing signals between nerve cells. In some cases it occurs in association with cancer (a paraneoplastic syndrome). Research regarding why specific antibodies attack the body's healthy cells is ongoing. Autoimmune Encephalitis generally occurs sporadically, in people with no family history of the condition
• Treatment may involve intravenous immunosuppressive therapy, and tumor removal when necessary. Early treatment decreases the likelihood for long-term complications, speeds recovery, and reduces the risk of recurrence (relapse). If not treated, the condition can lead to progressive neurologic deterioration and loss of life

(Source: Autoimmune Encephalitis; Genetic and Rare Disease Information Center (GARD) of National Center for Advancing Translational Science (NCATS), USA.)

Who gets Autoimmune Encephalitis? (Age and Sex Distribution)

• Autoimmune Encephalitis is a rare disorder. The presentation of symptoms may occur at any age
• Both males and females may be affected, although young women are the most affected
• Worldwide, individuals of all racial and ethnic groups may be affected

What are the Risk Factors for Autoimmune Encephalitis? (Predisposing Factors)

The risk factors for Autoimmune Encephalitis may include:

• Cancer
• Tumor in the ovaries (teratomas)
• Active or previous bacterial infection (Mycoplasma or Streptococcus sp.)

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Autoimmune Encephalitis? (Etiology)

No direct cause has been attributed to the development of Autoimmune Encephalitis. However, the following conditions are known to trigger an autoimmune response that may lead to Autoimmune Encephalitis:

• Certain cancers causing paraneoplastic syndrome
• Ovarian teratomas
• Active or previous infection by commonly occurring bacteria, such as Streptococcus and Mycoplasma

What are the Signs and Symptoms of Autoimmune Encephalitis?

The signs and symptoms of Autoimmune Encephalitis may include neurologic as well as psychiatric ones, and may vary among the affected individuals in type and severity.

The neurologic signs and symptoms may include:

• Weakness or numbness in parts of the body
• Abnormal or jerky movements
• Abnormal gait
• Impaired vision
• Slurring speech
• Slow speech
• Impaired memory
• Cognitive impairment
• Stupor
• Seizures

The psychiatric signs and symptoms may include:

• Anxiety
• Compulsive behavior
• Hallucinations
• Loss of inhibitions
• Aggressive behavior
• Inappropriate sexual behavior
• Excessive joy or sorrow
• Panic attacks

In addition to the above, the following additional signs and symptoms may be present:

• Nausea
• Loss of appetite; foods appear un-appealing
• Excessive eating
• Sleeplessness

How is Autoimmune Encephalitis Diagnosed?

Autoimmune Encephalitis is diagnosed on the basis of the following information:

• Complete physical examination
• Thorough medical history evaluation
• Assessment of signs and symptoms
• Laboratory tests
• Imaging studies
• Biopsy studies, if necessary

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Autoimmune Encephalitis?

The complications of Autoimmune Encephalitis may include:

• Conducting criminal activities due to aggression and loss of inhibition
• Risk of falls and injuries due to balance issues and seizures
• Weight loss due to loss of appetite
• Coma

Complications may occur with or without treatment, and in some cases, due to treatment also.

How is Autoimmune Encephalitis Treated?

The treatment for Autoimmune Encephalitis may involve the following measures:

• Steroids to reduce inflammation 
• Plasmapheresis to remove the autoantibodies 
• If possible, surgical excision of the tumor (if any) causing the autoimmune response
• Immunotherapy through intravenous immunoglobulin or IVIG treatment, which eliminates binding sites for autoantibodies
• Use of immunosuppressant drugs such as rituximab

How can Autoimmune Encephalitis be Prevented?

The exact cause of Autoimmune Encephalitis is not known, and hence, no methods or guidelines are available for its prevention.

• Seeking prompt medical treatment for medical conditions, such as tumors and cancers may decrease the likelihood of Autoimmune Encephalitis development
• Active research is currently being performed to explore the possibilities for treatment and prevention of disorders such as Autoimmune Encephalitis
• Regular medical screening at periodic intervals with tests and physical examinations are recommended

What is the Prognosis of Autoimmune Encephalitis? (Outcomes/Resolutions)

• The prognosis of Autoimmune Encephalitis is dependent upon the severity of the signs and symptoms and associated complications, if any
• A timely diagnosis and prompt treatment may slow its progression and aid in faster recovery times
• Some affected individuals may succumb to the complications arising from the condition
• It is reported that Autoimmune Encephalitis may recur within 2 years, in about 12% of the individuals who have recovered from the condition

Additional and Relevant Useful Information:

The following DoveMed website link is a useful resource for additional information:

http://www.dovemed.com/diseases-conditions/rare-disorders/