CME Review ArticleEmergency Department Presentations of Anti–N-Methyl-D-Aspartate Receptor EncephalitisAbe, Keith K. MD, MS; Koli, Roshni L. MD; Yamamoto, Loren G. MD, MPH, MBAAuthor Information From the Department of *Pediatrics and †Psychiatry, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI. Disclosure: The authors declare no conflict of interest. The authors and staff in a position to control the content of this CME activity and their spouses/life partners (if any) have disclosed that they have no financial relationships with, or financial interest in, any commercial organizations pertaining to this educational activity. Reprints: Loren G. Yamamoto, MD, MPH, MBA, Department of Pediatrics, University of Hawaii John A. Burns School of Medicine, 1319 Punahou St, 7th Floor, Honolulu, HI 96826 (e-mail: [email protected]). Pediatric Emergency Care: February 2016 - Volume 32 - Issue 2 - p 107-112 doi: 10.1097/PEC.0000000000000713 Buy CME Test Metrics Abstract Anti–N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is an acute autoimmune neurological disorder that presents with acute to subacute psychiatric and/or neurological complaints including new onset behavioral changes that may evolve to psychosis and catatonia, cognitive decline, new onset seizures, progressive encephalopathy, and/or movement disorders. Female teens and adults often have an associated ovarian teratoma as an underlying etiology, but most pediatric patients do not have an identifiable associated neoplasm. The diagnosis requires confirmatory serum and/or cerebrospinal fluid analysis findings of anti-NMDAR antibody titers. It can be misdiagnosed as a psychiatric condition or a viral encephalitis. The clinical features that distinguish anti-NMDAR encephalitis from a primary psychiatric disorder are the acute onset of the mood and behavioral changes with no history, the waxing and waning of consciousness (delirium/encephalopathy), and primary neurological features such as seizures and abnormal involuntary movements, including dyskinesias and dystonias. The prognosis is improved with earlier recognition and prompt immunotherapy treatment, making this an important diagnosis for emergency physicians. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.