A Pounding Problem: A Case of Recurrent Headache Caused by Anti-NMDA Receptor Encephalitis.

BACKGROUND:Anti-N-methyl-d-aspartate receptor (Anti-NMDAR) encephalitis is a serious autoimmune disease in which antibody production against the NMDA receptor results in profound neurotransmitter dysregulation. Patients may present with a wide variety of symptoms, including psychosis, orofacial dyskinesias, dysautonomia, hallucinations, mental status changes, seizures, and headaches. CASE REPORT:A previously healthy 25-year-old woman presented on several occasions to the Emergency Department with a severe pounding headache that initially responded well to treatment. She later developed signs consistent with meningoencephalitis along with altered mental status and neuropsychiatric changes. She was diagnosed with anti-NMDAR encephalitis after hospitalization. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Anti-NMDAR encephalitis is an under-recognized condition with diverse presentations. Recurrent headaches that improve with treatment may be an early sign of this disorder. Anti-NMDAR encephalitis should be considered in patients with recurrent undifferentiated headaches, and an appropriate work-up should be performed. Early recognition and diagnosis of this condition is critical to optimize favorable patient outcomes, as delays to diagnosis may lead to fatalities and long-term neurologic sequelae.