Anti NMDA Receptor Encephalitis
Anti-NMDA Receptor Encephalitis is occurs when the immune system mistakenly targets neurons in the brain, causing inflammation (encephalitis).
In this form of encephalitis, the body makes antibodies that bind to proteins on the NMDA receptor (GluN1/NR1 subunit). NMDA receptors are located on the outer surfaces of cells called neurons and are important to brain function.
This misdirected immune response causes inflammation and swelling in the brain (encephalitis). The NMDA receptors help neurons communicate. An immune response directed at these receptors can affect thinking, memory, mood, consciousness and breathing. These symptoms can be very serious and get worse over time.
This form of encephalitis affects about one in 1.5 million people. It affects females and males but is more common in females.
Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is a treatable autoimmune disorder characterized by prominent neuropsychiatric symptoms that predominantly affects children and young adults. In this review, we discuss the pathogenic mechanisms and immunologic triggers of anti-NMDAR encephalitis, and provide an overview of treatment and prognosis of this disorder, with specific focus on the management of common symptoms, complications, and patients during pregnancy. Most patients respond well to first-line treatment and surgical resection of tumors. When first-line immunotherapy fails, second-line immunotherapy can often improve outcomes. In addition, treatment with immunomodulators and tumor resection are effective treatment strategies for pregnant patients. Benzodiazepines are the preferred treatment for patients with catatonia, and electroconvulsive therapy (ECT) may be considered when pharmacological treatment is ineffective.
Although the majority of patients with anti-NMDAR encephalitis achieve favorable outcomes, those who received delayed or insufficient immunotherapy consistently experienced worse outcomes and were more prone to relapse. There is a need for sensitive diagnostic methods to enable early identification of this disease. In addition, current treatment strategies focus primarily on removal of antibodies in the periphery. However, antibodies present in the central nervous system are responsible for disease pathogenesis, which may explain why patients with anti-NMDAR encephalitis often require long hospital stays. Some drugs, such as bortezomib, azathioprine, and mycophenolate mofetil have been reported to be beneficial for patients who do not respond to tumor resection and immunosuppressive therapy; however, the effects of these medications have not been systematically verified in large cohorts. Additional studies are required to identify more effective treatment strategies. For patients with long-term sequelae, appropriate rehabilitation methods and improved strategies for the prevention of and monitoring for relapse are of critical importance.