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Abstract

Introduction: Case Report: Anti N-Methyl D- Aspartate Receptor antibody encephalitis is a rare paraneoplastic syndrome initially characterized in 2007 which presents with a wide spectrum of neurologic and psychiatric features and is often associated with ovarian tumors. Anti NMDA receptor Ab encephalitis is frequently misdiagnosed, but should be considered in any case of encephalitis with psychiatric symptoms or movement disorder. We present a case of Ant NMDA receptor antibody encephalitis in a 15 year-old female with initial presentation of seizures and agitation. Case Description: A 15 year-old previously healthy female presented to the ED for an episode of limb shaking and loss of consciousness. MRI brain and EEG were unremarkable and she was diagnosed with seizure disorder and discharged home on levetiracetam. 3 days later she retuned with complaints of visual and auditory hallucinations and jerking movements. She was switched to oxcarbazepine and discharged home. 2 days later she developed fever, confusion, and violent biting behaviors and EMS was called. The patient was given haloperidol and brought to an outside hospital where her initial labs were unremarkable, CT head negative. She was subsequently transferred to a tertiary care ICU. Physical examination revealed dysarthria, altered mental status, hypertonicity, choreatic movements and a Temp 101.2, BP 161/57, pulse 138, RR 29. Pertinent labs included WBC 13.0, CPK 9200, lactic acid 7.8 and lumbar puncture showing normal pressure xanthochromic fluid; 3wbc, glucose 70, protein 29, and no organisms on gram stain. She was treated for infectious encephalitis, with broad antibiotic and antiviral coverage. She did not improve, continued to be febrile and tachycardic with rising CPK. Treatment for NMS was initiated, but her course did not change. Her cerebrospinal fluid was positive for Anti NMDA receptor Ab and she was diagnosed with Anti NMDA receptor Ab encephalitis. She was treated with IVIG and high dose steroids with rapid clinical improvement. CT abdomen revealed an ovarian teratoma and she underwent unilateral oophorectomy. She was discharged and had complete recovery at 2 months.