Perelman School of Medicine at the University of Pennsylvania

Center for Autoimmune Neurology

Anti-NMDAR Encephalitis

What is anti-NMDA Receptor Encephalitis?

Anti-NMDA receptor encephalitis is a neurologic disease first identified by Dr. Josep Dalmau and colleagues at the University of Pennsylvania in 2007.  It is an autoimmune disease, where the body creates antibodies against the NMDA receptors in the brain.  These antibodies disrupt normal brain signaling and cause brain swelling, or encephalitis.  It can affect both men and women, however is more common among women.  It primarily affects the young, including children and young adults.  Some patients also have a tumor associated with this disease; the most common type is an ovarian teratoma in women. The name of this disease describes an immune attack on the NMDA receptors and can be explained as follows:

  • Anti- Autoimmune Response
  • NMDA Receptor- against NMDA receptors in the brain
  • Encephalitis- causing swelling and disruption in brain signaling

Signs & Symptoms

Anti-NMDA receptor encephalitis causes a wide range of symptoms varying in severity.   Patients typically start with less severe symptoms, and then rapidly progress to a condition requiring hospitalization.  The list below includes the most common symptoms.  Most patients with this disease exhibit nearly all of these symptoms; it is extremely uncommon for patients to have only one or two.

  • Behavior (paranoia, hallucinations, aggression, etc.)
  • Cognition
  • Memory Deficit
  • Speech Disorder
  • Loss of Consciousness
  • Movement Disorder (rhythmic motions with arms or legs, abnormal movements with the face or mouth)
  • Seizures
  • Autonomic Dysfunction

Titulaer, et. al., 2013


Anti-NMDA receptor encephalitis is often first identified through clinical symptoms.  Diagnosis is confirmed through lab testing of cerebral spinal fluid (CSF) or blood serum.  This testing is available at a variety of commercial labs, including the Hospital of the University of Pennsylvania (1-800-PENN LAB).


Treatment of anti-NMDA receptor encephalitis can vary according to patient, but typically includes a combination of the following:

First Line Treatment:

  • Tumor removal (if tumor is present)
  • Steroids
  • Plasma Exchange (plasmapheresis)
  • Intravenous immunoglulin (IVIG)

Second Line Treatment:

  • CellCept
  • Rituximab
  • Cytoxan


Recovery is slow and typically occurs in reverse of symptom onset.  The most severe symptoms typically resolve first while the cognitive, behavioral, and memory problems take longer to resolve.  Most patients will make a full recovery within two years of disease onset.   Predictors of positive outcomes include presence of a tumor, quick diagnosis, and aggressive treatment including second line therapies. 


Like most autoimmune diseases it is not known what exactly what causes anti-NMDAR encephalitis.  There are likely multiple environmental and genetic triggers that make people more susceptible to this disease, something we hope to pinpoint with future research.