2026 Clinician Corner - A rare case of anti–NMDA receptor encephalitis presenting with subacute neuropsychiatric symptoms in an older patient

Abstract 

Anti–NMDA receptor encephalitis is a rare autoimmune condition that often presents with delirium and seizures. While classically associated with younger women and ovarian teratomas, it can occur across a broader demographic and mimic a psychotic disorder or metabolic conditions. This case describes a 59-year-old woman with a history of fibromyalgia and depressive disorder who presented with subacute delirium, behavioral disturbances, and incontinence. Initial evaluations were unrevealing, and early diagnostic considerations attributed her presentation to a psychotic disorder. However, further workup, including cerebrospinal fluid antibody testing, confirmed anti–NMDA receptor encephalitis. This case underscores the diagnostic challenges posed by autoimmune encephalitis and highlights the importance of maintaining a broad differential. Anchoring bias and premature diagnostic closure can delay life-saving treatment; clinicians must remain vigilant when evaluating unexplained subacute neuropsychiatric decline.  

Keywords:  Anti-NMDA receptor encephalitis; encephalitis; COVID-19  

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Faculty credentials/disclosure 

The planners and faculty for this activity have no relevant financial relationships to disclose. The authors report no funding. Attempts were made to obtain consent from next of kin but they were unsuccessful. The IRB declined comment. Patient information is deidentified. 

Process

Click the "add to cart/begin" button, pay any relevant fee, take the quiz, complete the evaluation, and claim your CME credit.  You must achieve 100% on the quiz with unlimited attempts available.

  • By completing this process, you are attesting that you have read the journal article.

Expiration date:

Credit eligibility for this article is set to expire on July 1, 2027.

Learning Objectives

After completing the article, the learner should be able to:

  • Discuss anti–NMDA receptor encephalitis as a cause of subacute neuropsychiatric symptoms, seizures, and altered mental status in adults, particularly when initial infectious, metabolic, and psychiatric evaluations are unrevealing. 

  • Evaluate the diagnostic approach to suspected anti–NMDA receptor encephalitis, including the role of cerebrospinal fluid antibody testing and the limitations of neuroimaging, routine cerebrospinal fluid studies, and electroencephalography. 

  • Apply principles of management and prognosis in anti–NMDA receptor encephalitis, including recognition of potential postinfectious triggers such as COVID-19, the importance of early intervention, and factors associated with improved clinical outcomes. 

Key Points 

  • Anti–NMDA receptor encephalitis is a rare autoimmune encephalitis that may present with delirium, seizures, and symptoms attributable to a psychotic disorder.  

  • Early recognition and immunosuppression are associated with improved outcomes in all psychiatric domains and reduced disease severity.  

  • Diagnosis relies on cerebrospinal fluid testing for anti–NMDA receptor antibodies.  

  • Viral infections, including herpes simplex virus and COVID-19, are potential postinfectious triggers.  

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Course summary
Available credit: 
  • 1.00 American Board of Internal Medicine (ABIM) MOC Part 2

    Successful completion of this CME activity, which includes participation in the evaluation component, enables the participant to earn up to 1.00 MOC points in the American Board of Medicine’s (ABIM) Maintenance of Certification (MOC) program. It is the CME activity provider’s responsibility to submit participant completion information to ACCME for the purpose of granting ABIM MOC credit.

  • 1.00 American Board of Surgery (ABS) Accredited CME

    Successful completion of this CME activity enables the learner to earn credit toward the CME requirement of the American Board of Surgery’s Continuous Certification program. It is the CME activity provider's responsibility to submit learner completion information to ACCME for the purpose of granting ABS credit.

     

     

  • 1.00 AMA PRA Category 1 Credit™
    The A. Webb Roberts Center for Continuing Medical Education of Baylor Scott & White Health is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to provide continuing medical education for physicians.
  • 1.00 Attendance
Course opens: 
07/01/2026
Course expires: 
07/01/2027
Cost:
$25.00

Sindhoora Koneru, BS¹, Blake Oliaro, MD², and Tyler Tepfenhart, DO² 

 

¹University of the Incarnate Word School of Osteopathic Medicine, San Antonio, Texas, USA 

²Department of Internal Medicine, Baylor Scott & White Medical Center – Round Rock, Round Rock, Texas, USA 

 

Corresponding author: Sindhoora Koneru, University of the Incarnate Word School of Osteopathic Medicine, 7615 Kennedy Hill Dr., San Antonio, TX 78235 (e-mail: [email protected]) 

Accreditation

The A. Webb Roberts Center for Continuing Medical Education of Baylor Scott & White Health is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to provide continuing medical education for physicians.

Designation

AMA PRA Category 1 Credit™

The A. Webb Roberts Center for Continuing Medical Education of Baylor Scott & White Health designates this Journal-based CME activity for a maximum of 1.0 AMA PRA Category 1 Credit™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

ABS CC

Successful completion of this CME activity enables the learner to earn credit toward the CME requirement of the American Board of Surgery’s Continuous Certification program. It is the CME activity provider's responsibility to submit learner completion information to ACCME for the purpose of granting ABS credit.

ABIM MOC

 Successful completion of this CME activity, which includes participation in the evaluation component, enables the participant to earn up to 1.0 MOC points in the American Board of Internal Medicine’s (ABIM) Maintenance of Certification (MOC) program. It is the CME activity provider’s responsibility to submit participant completion information to ACCME for the purpose of granting ABIM MOC credit.

Available Credit

  • 1.00 American Board of Internal Medicine (ABIM) MOC Part 2

    Successful completion of this CME activity, which includes participation in the evaluation component, enables the participant to earn up to 1.00 MOC points in the American Board of Medicine’s (ABIM) Maintenance of Certification (MOC) program. It is the CME activity provider’s responsibility to submit participant completion information to ACCME for the purpose of granting ABIM MOC credit.

  • 1.00 American Board of Surgery (ABS) Accredited CME

    Successful completion of this CME activity enables the learner to earn credit toward the CME requirement of the American Board of Surgery’s Continuous Certification program. It is the CME activity provider's responsibility to submit learner completion information to ACCME for the purpose of granting ABS credit.

     

     

  • 1.00 AMA PRA Category 1 Credit™
    The A. Webb Roberts Center for Continuing Medical Education of Baylor Scott & White Health is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to provide continuing medical education for physicians.
  • 1.00 Attendance

Price

Cost:
$25.00
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