Anti-NMDA receptor encephalitis

Abstract

Autoimmune diseases of the central nervous system (CNS) are one of the most socially and economically significant problems of neurology. Despite the identification of new nosological forms of autoimmune encephalitis, the creation of diagnostic panels for the verification of autoantibodies in biological fluids, and the use of highly effective pathogenetic therapy, the number of diagnostic errors remains high, which poses a threat to the patient’s life and a high risk of developing severe complications. Anti-N-methyl-D-aspartate receptor encephalitis (anti-NMDAR encephalitis) is autoimmune encephalitis caused by the presence of antibodies (Ab) to the NR1 subunit of NMDA-receptors (NMDAR) characterized by the development of severe mental and neurological deficits in a previously healthy person. This article summarizes the recent literature on anti-NMDAR encephalitis. The literature search was carried out using the Scopus, Web of Science, Pubmed, CyberLeninka databases. The review presents the facts of the history of the study of the disease, epidemiological data, modern ideas about the pathogenetic mechanisms of the development of the disease, the spectrum of clinical manifestations and various forms of the course of the disease. The diagnostic criteria and research methods used to confirm the diagnosis are described, approaches to the treatment of anti-NMDAR encephalitis are outlined. Anti-NMDAR encephalitis is clinically manifested by a combination of mental disorders, epileptic seizures, speech and extrapyramidal disorders, and disturbances in the rhythm of sleep and wakefulness. The disease occurs at any age. The development of the disease can be associated with such immunological triggers as oncological process and herpetic encephalitis, or be idiopathic in nature. There are features of the course of the clinical picture depending on the age of the patient, paraneoplastic or postherpetic aetiology of the disease. The diagnostic algorithm, along with neuroimaging, determination of specific antibodies, electroencephalography, should also include the search for an oncological process. The recovery of patients can take from several months to years. In some cases, persistent neurological deficits develop. Predictors of a favourable outcome include early initiation and use of combination therapy, detection and removal of neoplasms, a low titer of anti-NMDAR antibodies, and age of patients over 12 years of age. In up to 25% of cases, a relapsing course of the disease is possible, and therefore requires long-term monitoring of these patients.