UMEM Educational Pearls

Category: Toxicology

Title: Beware anti-NMDA receptor encephalitis mimicking NMS

Keywords: nms, neuroleptic malignant syndrome, anti-NMDAR encephalitis (PubMed Search)

Posted: 10/4/2013 by Bryan Hayes, PharmD (Emailed: 10/10/2013) (Updated: 10/10/2013)
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Toxicologists should be aware of non-toxicological mimics of delirium, including anti-NMDA receptor encephalitis. It is an under-recognized progressive neurological disorder caused by antibodies against NMDA receptors.

Cases often present with altered mental status, autonomic instability, increased muscle tone, and movement disorders. It can easily be mistaken for neuroleptic malignant syndrome (NMS). A new case series describes two such patients for which toxicologists were consulted.

Must read links:

Dr. Leon Gussow provides a great review of the case series on his Poison Review blog.

Dr. Chris Nickson reviews the basics of the disease on the Life in the Fast Lane blog.


Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis: an etiology worth considering in the differential diagnosis of delirium. Clin Toxicol 2013;51(8):794-7. [PMID 23962100]

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