Anti-NMDA Receptor Encephalitis
The neurological condition resulting in sudden and severe behavioral changes.
By Jenny Ewen, BA, NREMT
First identified in 2007 by Dr. Joseph Dalmau, anti-NMDA receptor encephalitis is an auto-immune disease where antibodies attack the NMDA receptors in the brain (specifically the GluN1 subunit), causing a litany of symptoms due to the disruption in signals from the brain and swelling in brain tissue.
NMDA stands for N-methyl-D-aspartate, and anti- indicates that it’s an autoimmune response in the body. Encephalitis means swelling in the brain, causing several neurological symptoms, including behavioral changes, seizures, and coma.
NMDA receptors are responsible for the processes of learning and memory, and are located in neurons in the brain. NMDA receptors are also involved in other neurological disorders, including Alzheimer’s and depression.
Anti-NMDA receptor encephalitis is still quite difficult to identify from other psychiatric disorders, but most commonly occurs in children and young adults and most often in women. It is not yet known what causes it, but environmental and genetic triggers are suspected to be involved.
Signs and Symptoms
Anti-NMDA receptor encephalitis can develop over weeks or months with symptoms increasing in severity during that time and requiring hospitalization.
While often diseases present with many symptoms and a patient could experience only some of them, people who develop anti-NMDA receptor encephalitis typically present with nearly all of the symptoms by the time it’s diagnosed. In 90% of diagnosed cases, patients experience severe psychiatric/behavioral symptoms.
- Changes in behavior, including paranoia, hallucinations, and agitation
- Worsening memory
- Difficulty speaking
- Problems with cognition (thinking, learning, etc.)
- Abnormal physical movement
- Altered autonomic functions (breathing and heart rate)
When left undiagnosed and untreated, anti-NMDA receptor encephalitis can ultimately be fatal.
While anti-NMDA receptor encephalitis remains difficult to diagnose, Dr. Dalmau and his colleagues created an acronym to help identify diagnostic clues when assessing a patient experiencing psychiatric symptoms that have come on suddenly.
SEARCH for NMDAR-A covers the criteria:
- Sleep dysfunction
- Rapid onset
- Child and young adult predominance
- History of psychiatric disease absent
- Fluctuating catatonia
- Negative and positive symptoms
- Memory deficit
- Decreased verbal output
- Antipsychotic intolerant
- Rule out neuroleptic malignant syndrome (reaction to neuroleptic medications presenting with some similar symptoms)
- Antibodies (and additional testing, including MRI, CSF studies, and electroencephalogram)
Following this diagnosis criteria, anti-NMDA receptor encephalitis may be more easily diagnosed, and diagnosed more quickly.
Treatment & Recovery
Treatment can vary depending on the specific case and the patient, but typically includes steroids, plasma exchange, intravenous immunoglobulin (extracted from the plasma in blood), and further immunotherapy medications.
If there is a tumor present, surgery and treatment on the tumor can help relieve symptoms. Supportive care with psychiatric treatment can also prove helpful.
The recovery can take months and, rarely, some patients experience dramatic recovery within the first few weeks which may indicate a different underlying condition.
The most severe symptoms typically resolve first but the behavioral and cognitive symptoms can take much longer to resolve, lasting up to a year or two in some patients.
Sources and More Information
Medscape, “Anti-NMDA Receptor Encephalitis or Primary Psychiatric Disorder?” https://www.medscape.com/viewarticle/929796
“Intravenous Immunuglobulin” https://emedicine.medscape.com/article/210367-overview
NPR, “A Young Report Chronicles Her ‘Brain On Fire’” https://www.npr.org/2012/11/14/165115921/a-young-reporter-chronicles-her-brain-on-fire
OHSU, “Puzzling brain disease could now be better diagnosed, treated” https://news.ohsu.edu/2019/07/10/puzzling-brain-disease-could-now-be-better-diagnosed-treated
Perelman School of Medicine - University of Pennsylvania, “Anti-NMDAR Encephalitis” https://www.med.upenn.edu/autoimmuneneurology/nmdar-encephalitis.html
UC Santa Barbara - The Current, “Brain on Fire” https://www.news.ucsb.edu/2019/019546/brain-fire
U.S. National Library of Medicine, National Institutes of Health - PMC, “To Hell and Back Review: Brain on Fire: My Month of Madness” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3704309/
More from The Allied Times
By Joanne Ewen, Program Administrator and Certified CPR InstructorPeople are often confused about CPR training and which level of training is appropriate for their needs. I am a Faculty Member of the Multi-Regional Training Center (MRTC) for the American Heart Association (AHA), so I’m offering a quick review of their main courses. Beside the AHA…
By Jennifer EwenWhen you’re focused on so many things involved with being in EMS, it’s easy to forget that not only does your mind need to be conditioned in order to know how to help patients, your body needs to be in top shape too. Most importantly, you need a strong core. Moving patients onto stretchers,…
By Marven Ewen, MD, Medical DirectorThe purpose of the Primary Assessment (aka Primary Survey or Initial Assessment) is to determine the nature of the primary complaint and rule out, prioritize, and treat any immediate life-threatening airway, breathing and circulation problems. The purpose of the Secondary Assessment is to fill in gaps in your understanding of…
By Jennifer EwenIf you haven’t gotten on the smoothie bandwagon yet, saddle up. You don’t have to be an all-natural vegan yogi to enjoy all the benefits smoothies have to offer. The best part of smoothies is their portability – if you’re bringing a water bottle to your shift (you are, right?), then you can…
By James Ewen, Exam CoordinatorThe NREMT skills exam can be a stressful event for everyone involved. To help ease the stress and keep things organized, here are some DOs and DON’Ts for exam day.DO: Arrive at least 15 minutes before the exam is set to begin. This will give you time to sign in and…
By Marven Ewen, MDMedical DirectorEbola is a deadly virus that causes hemorrhagic fever and up until earlier this year has only been seen in a few sporadic outbreaks in small central African communities. The current outbreak is much larger and more sustained than any previously seen, having spread to several West African countries and now…