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  • Gonzalo Laje

Diagnosing Autoimmune Encephalitis

learn more about  Autoimmune Encephalitis and other conditions that affect the brain.

The National Institutes of Health describes Autoimmune Encephalitis as “a group of conditions that

occur when the body's immune system mistakenly attacks healthy brain cells, leading to inflammation of the brain.”

Among the collection of inflammatory brain diseases, Autoimmune Encephalitis causes are one of the most mysterious, potentially due to a malignancy, following viral encephalitis, or occurring with no identified trigger. Furthermore, some of the symptoms of autoimmune encephalitis may manifest months after the infection.

According to the Mayo Clinic, among these symptoms, the most common include the following, which often are associated with other diseases, infections, and conditions:

• Behavioral/personality changes

• Psychosis

• Memory and cognitive deficits

• Hallucinations

• Seizures

• Changes in vision

• Sleep problems

• Muscle Weakness

• Loss of sensation

• Problems walking

• Bladder and bowel problems

• Abnormal movements

• Dysautonomia

• Altered levels of consciousness

Because of the wide variety of symptoms, and the problem that different people present with a varying

combination of these, it can be hard to identify that Autoimmune Encephalitis is the problem,

particularly since other, more common health conditions present similarly.

So, for example, a person presenting with seizures might be diagnosed with epilepsy, and another patient with hallucinations would fit a diagnosis of schizophrenia. Unfortunately, the most unequivocal means of diagnosing Autoimmune Encephalitis is a brain biopsy, an invasive and risky procedure in living patients.

The general recommendations for diagnosis focus on a prompt diagnosis of patients with a “subacute

onset of memory deficits or altered mental status with or without other signs or symptoms.” The

urgency of diagnosis lies in the evidence that early immunotherapy treatment improves clinical

outcomes. Corticosteroids, intravenous immunoglobulins, and plasmapheresis are among the first line

of treatments for Autoimmune Encephalitis, with some patients showing rapid improvement. In

contrast, other patients either fail to respond or take 8 to 20 months to show improvement.

Diagnosis begins with neurologic evaluation and proceeds with standard diagnostic testing using MRI,

EEG, and/or CSF (spinal tap). Instead of waiting for the latter results, treatment should be initiated

immediately. The following three criteria must be met for a diagnosis:

1. A rapid progression of fewer than three months of short-term memory loss, altered mental

status, or psychiatric symptoms;

2. A finding of new focal CNS, unexplained seizures, high white blood cell count, or an MRI with

findings consistent with encephalitis and

3. Reasonable exclusion of alternative causes.

Certain other health conditions may coexist with Autoimmune Encephalitis, including ovarian tumors,

faciobrachial dystonic seizures (frequent brief seizures primarily affecting the arm and face), and

neuromyotonia (spontaneous muscle activity, including twitching). The presence of these issues is a

strong indicator that the person should be assessed for Autoimmune Encephalitis. Conversely, suppose a patient presents with diagnostic indicators of Autoimmune Encephalitis, including an MRI revealing

bilateral brain abnormalities in the medial temporal lobes. In that case, care should be given to examine

the patient for potential comorbidities, particularly potential cancers, including ovarian, lung, and


The occurrence of autoimmune encephalitis is rare, but as more information is gained about its

manifestations, symptoms, and diagnosis, it is possible to detect and treat it. To learn more about

Autoimmune Encephalitis and other conditions that affect the brain and body, contact Washington

Behavioral Medicine Associates to schedule an appointment to speak with one of our practitioners.


Director, WBMA


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