Autoimmune Psychosis Exists - Early Diagnosis of an Anti-NMDA Receptor Autoimmune Encephalitis Presenting as First-Episode Psychosis in a 25-Year-Old Male - A Case Report

Sep 28, 2026

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Autoimmune encephalitis due to anti-NMDA receptor antibodies can initially present to psychiatry as first-episode psychosis. A 25-year-old man developed subacute psychotic symptoms with fluctuating neuropsychiatric manifestations, including cognitive impairment, disorientation, confusion, movement disorders, decreased consciousness, catatonia complicated by malignant neuroleptic syndrome, and seizures. EEG showed an extreme delta brush pattern and CSF revealed elevated IgG index, with antibody confirmation after initial treatment. Early immunosuppression using corticosteroids followed by plasmapheresis led to significant clinical improvement before confirmation at discharge.

LanguageEnglish

CategoryHealthcare

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Pages6

Reading Time15 min

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Case Report

Clinical Presentation

Diagnosis and Treatment

Clinical Significance

Wiley Case Reports in Psychiatry Volume 2025, Article ID 3931587, 6 pages [https://doi.org/10.1155/crps/3931587](https://doi.org/10.1155/crps/3931587) Case Report Autoimmune Psychosis Exists: Early Diagnosis of an Anti-NMDA Receptor Autoimmune Encephalitis Presenting as First-Episode Psychosis in a 25-Year-Old Male—A Case Report Marc Mourad , 1 Caroline Hallal,2 Juliana Sargi,3 Elie Atallah,4 Anthony Kassab,2 Sajida Sabsaby,5 Christian Matta ,5 Karine Abou Khaled ,5 and Sami Richa2 1Department of Psychiatry, Psychiatric Hospital of The Cross, Jal El Dib, Maten, Lebanon 2Department of Psychiatry, Faculty of Medicine, Saint Joseph University of Beirut, Beirut, Lebanon 3Department of Psychiatry, University of Tours, Tours, France 4Department of Psychology and Social Sciences/School of Medicine and Medical Sciences, Holy Spirit University of Kaslik, Jounieh, Lebanon 5Department of Neurology, Faculty of Medicine, Saint Joseph University of Beirut, Beirut, Lebanon Correspondence should be addressed to Marc Mourad; [marcmourad299@gmail.com](marcmourad299@gmail.com) Received 26 July 2025; Revised 20 November 2025; Accepted 1 December 2025 Academic Editor: Toshiya Inada Copyright © 2025 Marc Mourad et al. Case Reports in Psychiatry published by John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. Background: Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an autoimmune disorder marked by prominent neuropsychiatric symptoms. It is typically ﬁrst encountered by psychiatrists because psychotic symptoms can be early signs of the condition. In recent years, this form of encephalitis has been established as a distinct diagnostic entity in neurology and psychiatry. Furthermore, as an organic and autoimmune psychosis, it is considered a differential diagnosis of schizophrenia and schizoaffective disorders. Clinical Presentation: We report the case of a 25-year-old male who presented with a ﬁrst episode of psychosis. During his stay, the patient exhibited severe cognitive deﬁcits (disorientation, confusion, memory issues), movement disorders (dysarthria, perioral dyskinesia leading to speech difﬁculties), a decreased level of consciousness, and a catatonic state complicated by a malignant neuroleptic syndrome. The patient also experienced epileptic seizures and had unstable vital signs. An electroencephalogram (EEG) revealed an extreme delta brush pattern (speciﬁc for anti-NMDAR encephalitis), and CSF analysis showed an elevated immunoglobulin G (IgG) index. Based on these ﬁndings, anti-NMDAR autoimmune encephalitis was suspected 17 days after admission but not yet conﬁrmed. The patient was treated with oral corticosteroids followed by plasmapheresis and showed signiﬁcant improvement. At discharge, he was alert, oriented, cooperative, and not psychotic, with only mild cognitive defects. Days after discharge, anti-NMDAR IgG antibodies were detected in his CSF, conﬁrming the diagnosis. Clinical Presentation: This case underscores the importance of considering anti-NMDAR autoimmune encephalitis as a differential diagnosis in patients with no personal or family psychiatric history who develop subacute psychotic symptoms (lasting less than 3 months) along with ﬂuctuating neuropsychiatric signs. Conducting an EEG, cerebral MRI, and CSF analysis to conﬁrm or exclude the condition, followed by early immunosuppressive treatment, is crucial for improving prognosis. Keywords: autoimmune diseases; early diagnosis; encephalitis; extreme delta brush EEG aspect; ﬁrst episode of psychosis; immunotherapies; psychosis 2 Case Reports in Psychiatry 1. Introduction to the psychiatric ward without further investigation other thana routine blood test, including CBC, which showed normal Since the exact pathophysiology of schizophrenia spectrum

FAQs

What clinical features did the 25-year-old male present with?

He presented with first-episode psychosis and developed severe cognitive deficits, disorientation and confusion, movement disorders with perioral dyskinesia, decreased consciousness, and catatonia. He also had epileptic seizures, unstable vital signs, and malignant neuroleptic syndrome complicating the course.

How was anti-NMDA receptor autoimmune encephalitis diagnosed?

An EEG showed an extreme delta brush pattern, and CSF analysis demonstrated an elevated IgG index, leading clinicians to suspect anti-NMDAR encephalitis. Anti-NMDAR IgG antibodies in CSF were detected after discharge, confirming the diagnosis.

What treatment resulted in improvement?

He was treated with oral corticosteroids followed by plasmapheresis. By discharge, he was alert and oriented, cooperative, and not psychotic, with only mild cognitive defects.

Sep 28, 2026

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