Against the Odds: A Complex Case of Anti-NMDA-Receptor Encephalitis Triumphantly Treated With Extended IVIG Course

Abstract Background: Anti-NMDA receptor encephalitis is a rare autoimmune disorder marked by neuropsychiatric symptoms and IgG antibodies against NMDA receptors. Often triggered by ovarian teratomas or viral infections, it presents with seizures, dyskinesias, and psychiatric symptoms. This report details a complex case successfully treated. Case Presentation: A 25-year-old female with a history of schizoaffective disorder, postpartum depression, and obesity presented with bizarre behavior, including agitation, aggression, and decreased sleep over 2 months. Initially admitted to a psychiatric unit for suspected psychotic decompensation, she experienced loss of consciousness and was subsequently transferred to a medical floor. Neuroimaging and EEG results were inconclusive. Given her age, gender, unusual presentation, and lack of improvement, Anti-NMDA receptor encephalitis was suspected. CT scans revealed bilateral teratomas, and NMDA autoantibodies were positive (titer 1:32). She underwent cystectomy of the teratomas and was started on IVIG. Following the first IVIG session, she desaturated, requiring intubation and transfer to the ICU. In the ICU, she received a total of 7 IVIG sessions and antibiotics for suspected meningitis. She also experienced cardiac pauses lasting 3-8 seconds, prompting consideration of a pacemaker, which was not placed due to suspected sepsis. She gradually improved, extubation, and continued recovery. Discussion: This case report highlights the complexities in diagnosing and treating NMDA receptor encephalitis, a condition that often presents with primarily neuropsychiatric symptoms and significant management challenges. A 25-year-old female with a history of psychiatric disorders presented with agitation, aggression, and altered consciousness, leading to a psychiatric admission for suspected psychosis. Initial neuroimaging and EEG results were inconclusive, and she did not respond to antipsychotic medications. NMDA receptor encephalitis was confirmed through positive autoantibody testing (titer 1:32), underscoring the importance it. Bilateral teratomas were discovered, necessitating tumor resection; a cystectomy was performed due to the patient's young age and family consent issues. The patient also experienced cardiac complications, including pauses up to 8 seconds. Pacemaker was deferred due to the patient's improvement and positive blood culture findings. Despite these complications, the patient showed significant improvement after seven IVIG sessions, emphasizing the importance of a multidisciplinary approach involving neurology, psychiatry, cardiology, surgery, and critical care for optimal outcomes. Conclusion: This case highlights the need to consider NMDA receptor encephalitis in patients with acute neuropsychiatric symptoms, especially when diagnosis is unclear. The condition is more common in young females and linked to teratomas and cardiac issues. Timely diagnosis, tumor resection, and immunotherapy are crucial for better outcomes.