Clinical Pearls & Morning Reports
Anti–N-methyl-d-aspartate (NMDA) receptor antibodies were first identified in 2007 in patients who presented with new-onset psychosis, seizures, and autonomic dysfunction and had a response to immunotherapy. Read the latest NEJM Case Records of the Massachusetts General Hospital here.
Q: How common is anti–NMDA receptor encephalitis?
A: It is now understood that anti–NMDA receptor antibodies are a common cause of encephalitis with movement disorder and, more broadly, were the most commonly identified cause of encephalitis among patients 30 years of age or younger in the California Encephalitis Project.
Q: Is anti–NMDA receptor encephalitis commonly associated with tumors in all age groups?
A: Anti–NMDA receptor encephalitis can be associated with tumors, but tumor-associated disease is uncommon in young children. Moreover, 94% of patients with tumor-associated anti–NMDA receptor encephalitis are female, and no cases of tumor-associated disease have been reported in boys.
A: Among patients younger than 18 years of age, the most common manifestations of anti–NMDA receptor encephalitis include behavioral changes and seizures. Among children younger than 12 years of age, movement disorders are common. Among adults with anti–NMDA receptor encephalitis, the most prevalent findings are behavioral changes, seizures, cognitive dysfunction, and memory problems; movement disorders are seen less frequently in adults than in children. Results on MRI of the head are reportedly normal in half of patients with anti–NMDA receptor encephalitis. In the other half, T2-weighted FLAIR images may reveal signal hyperintensity involving the hippocampi, cerebral or cerebellar cortex, basal ganglia, brain stem, and spinal cord. Contrast enhancement and restricted diffusion in the involved areas are less commonly encountered. Brain atrophy may also be seen and is often reversible.
A: First-line treatment for anti–NMDA receptor encephalitis is intravenous glucocorticoids, intravenous immune globulin, or plasma exchange. If a tumor is identified, surgical resection is also considered.