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Autoimmune Encephalopathy

Autoimmune encephalopathy
is increasingly recognized

Many cases of encephalopathy previously considered infectious are now recognized to have an autoimmune cause. In fact, based on a recent Mayo Clinic study, autoimmune encephalitis was found to be as common as infectious encephalitis.1

When to consider testing

Consider autoimmune testing for patients presenting with new-onset encephalopathy (non-infectious or metabolic) and one or more of the following:

  • Headache
  • Autoimmune stigmata (e.g., physical signs or personal/family history of diabetes, thyroid disorder, vitiligo, prematurely gray hair, myasthenia gravis, rheumatoid arthritis, systemic lupus erythematosus)
  • History of cancer
  • Smoking history (20+ pack years) or other cancer risk factors

  • Inflammatory cerebrospinal fluid
  • Neuroimages suggesting inflammation (signal abnormality, limbic or extra-temporal)
  • Prior treatment with immune checkpoint inhibitors
  • Antibody prevalence in epilepsy and encephalopathy (APE2) score is ≥41

Which test should I order?


Beyond the Test Result

Greg Widseth was suddenly hit by a rare disease that prompted his immune system to attack his brain cells, resulting in as many as 60 seizures a day. Special blood and spinal fluid tests developed by Mayo Clinic Laboratories confirmed that Widseth had antibodies known to target certain brain cells.

Learn more about how to order this evaluation at your institution.

Antibodies included:

Plasma membrane specificities

Nuclear and cytoplasmic specificities

Additional Resources

Nailing the suspect: The prevalence of autoimmune encephalitis vs. infectious encephalitis

For people with encephalitis, rapid treatment of their acute brain inflammation is critical for avoiding devastating physical and cognitive deficits. But appropriate treatment requires identifying the culprit causing the symptoms.

A Test in Focus - Autoimmune encephalopathy evaluations

Andrew McKeon, M.B., B.Ch., M.D., gives an overview of the autoimmune encephalopathy evaluations. He focuses on when the tests should be ordered, how this testing improves upon previous approaches, and what clinical action the results enable. 

When the body attacks the brain: Immune system often to blame for encephalitis, study finds

Encephalitis caused by the immune system attacking the brain is similar in frequency to encephalitis from infections, Mayo Clinic researchers report in Annals of Neurology.