N-Methyl-d-aspartate Receptor Antibody Encephalitis: A Concise Review of the Disorder, Diagnosis, and Management

Abstract

Anti-NMDA ( N-methyl-d-aspartate) receptor (anti-NMDAR) encephalitis is one of the most common paraneoplastic encephalitides. It occurs in both sexes, across all age ranges, and may occur in the presence or absence of an associated tumor. Its pathogenesis and clinical presentation relate to the presence of IgG1 or IgG3 antibodies targeting the NR1 subunit of the NMDA receptor, leading to a disinhibition of neuronal excitatory pathways. Initial clinical manifestations may be nonspecific, resembling a viral-like illness; however, with disease progression, symptoms can become quite severe, including prominent psychiatric features, cognitive problems, motor dysfunction, and autonomic instability. Anti-NMDAR encephalitis may even result in death in severe untreated cases. Diagnosis can be challenging, given that initial laboratory and radiographic results are typically nonspecific. The majority of patients respond to first or second-line treatments, although therapeutic options remain limited, usually consisting of tumor removal (if there is confirmation of an underlying malignancy) in conjunction with prompt initiation of immunosuppressive medications along with intravenous immunoglobulins and/or plasma exchange. Although the clinical presentation of anti-NMDAR encephalitis overlaps with several other more common neurological and psychiatric disorders, early diagnosis and treatment is essential for a positive prognosis. Here, we concisely review the pathogenesis, diagnosis, and clinical management of this disease.

Clinical analysis of anti-NMDAR encephalitis combined with MOG antibody in children

“…Anti-NMDA receptor encephalitis is the most common autoimmune encephalitis in school age children around 9 years old in which autoantibodies bind to NMDA receptors in the brain to cause inflammatory diseases of the limbic system [1,5,6] . Myelin oligodendrocyte glycoprotein (MOG) is a glycoprotein that is located on the surface of the myelin sheath and is found only in the central nervous system (CNS).The MOG antibody-related disease is an inflammatory demyelinating syndrome of CNS, manifesting monophasic or recurrent neurological dysfunction.…”

“…The relapsed patients were still effective to first-line therapy and had no relapses after prolonged corticosteroid maintenance therapy. Anti-NMDAR encephalitis progresses rapidly, and quite a significant cases require intensive care because of status epilepticus or central hypoventilation [5] , while MOG related disease are prone to relapse and leave residual neurological impairment that some of them need to start second-line immunotherapy [15] . The overlap of the two antibodies may have a protective effect.…”

Effectiveness of Mycophenolate Mofetil in the Treatment of Pediatric Anti-NMDAR Encephalitis: A Retrospective Analysis of 6 Cases

“…Early diagnosis and treatment can improve the prognosis of patients with anti-NMDAR encephalitis (22,23). However, recurrence remains a problem for both patients and physicians.…”

Not Your Average Seizure: A Case of N-Methyl-D-Aspartate Receptor Encephalitis and Review of Literature

“…NMDA receptor encephalitis associated with a tumor generally has a favorable prognosis with tumor resection. Conversely, cases not associated with a tumor are more likely to have disease relapse [12]. Early diagnosis and treatment also confer a favorable prognosis.…”