Autoimmune encephalitis (AE) is a type of brain inflammation where the body’s immune system attacks healthy cells and tissues in the brain or spinal cord. It is a rare, complex disease that can cause rapid changes in both physical and mental health. Some patients have antibodies in their blood or cerebrospinal fluid (CSF) which are known to be associated with encephalitis, while others test negative for antibodies but have characteristic symptoms. Certain forms of encephalitis may be associated with some types of tumors, particularly ovarian tumors. AE was recognized as a disease relatively recently. Because of this, some doctors may not be familiar with this condition, and it may be misdiagnosed as a psychiatric or neurological disorder. Early diagnosis and treatment are critical to minimizing both short- and long-term complications of this disease.
Inflammation in the brain can cause a variety of symptoms, including neurological and psychiatric problems. Symptoms often vary from patient to patient. They can include an sudden decline in work or school performance, loss of the ability to speak, abnormal body movements or seizures, vision loss, weakness of the arms or legs, and sleep problems. Psychiatric manifestations can range from anxiety and mood changes to psychosis with hallucinations, delusions or catatonia. The symptoms typically develop quickly over weeks to a few months. Long-standing psychiatric issues (for many months or years) are not a sign of autoimmune encephalitis.
The diagnosis of autoimmune encephalitis is best made by a multidisciplinary healthcare team made up of rheumatologists (or pediatric rheumatologists), neurologists, psychiatrists and other specialists. Diagnosis requires a thorough history and physical exam, as well as lab studies and imaging. If AE is suspected, a doctor may recommend doing a lumbar puncture to evaluate the cerebral spinal fluid for antibodies, including the NMDA antibody. An ultrasound of the abdomen may also be performed rule out the possibility of an associated tumor. Diagnostic testing also typically includes a brain MRI, and an electroencephalogram (EEG) test, which measures brain waves. Other causes of brain inflammation, such as infection, must be ruled out before a diagnosis of AE can be made.
Treatment varies depending on the severity of the disease. Corticosteroids and other immunosuppressive medications are typically used to control the inflammation in the brain. Some patients may also require medications for seizures or psychiatric symptoms. If an ovarian or other tumor is found, surgically removing it can significantly improve the patient’s AE. Once the underlying encephalitis is controlled, long-term rehabilitation, including physical, occupational and speech therapy, may help patients regain function.
Reviewed and edited by Sarah Faith Taber, MD