Recurrent Anti-NMDAR Encephalitis Necessitating Oophorectomy in an Adolescent Patient: A Case Report

Background: Anti-NMDA receptor (A-NMDAR) encephalitis is an autoimmune condition often associated with ovarian teratoma. Surgical removal of the teratoma is generally curative, and recurrence is uncommon. Case: A 14-year-old female presented with psychiatric symptoms and was ultimately diagnosed with A-NMDAR encephalitis during a prolonged hospitalization. She was found to have bilateral ovarian teratomas, underwent laparoscopic bilateral ovarian cystectomy, and returned to neurologic baseline within 2 months. One year later, the patient was re-presented with similar symptoms and was diagnosed with recurrent A-NMDAR encephalitis. Initial imaging was negative for ovarian teratomas. After another prolonged hospitalization, repeat imaging ultimately demonstrated a suspected left ovarian teratoma. A left salpingo-oophorectomy was performed, and the patient's condition again fully recovered. Conclusion: This case of A-NMDAR encephalitis presented with many atypical features including neuropsychiatric presenting symptoms, bilateral teratomas, and severe recurrence of disease. While imaging is the recommended modality for investigation of etiology, no teratoma was identified on the second presentation, leading to an ethical and clinical conundrum in this adolescent patient. More research is needed to investigate other diagnostic methods for A-NMDAR encephalitis without distinct teratoma on imaging in female patients.