Polymorphism of autoimmune encephalitis

This review analyses the current understanding and diagnostic approaches to the management of patients with autoimmune encephalitis. Cellular and synaptic targets, involved in the pathological process in autoimmune encephalitis, are described. The presence of clinical and immunological differences in the pathology is emphasized: on the one hand, non-structural damage to the nervous system is combined with the subacute development of cognitive impairment, epileptic and psychopathological syndromes, which, on the other hand, are associated with polymorphic immunological heterogeneity. The algorithm for clinical and laboratory diagnosis is described, based on our own clinical observations of three patients. The first patient was diagnosed with a cross-autoimmune syndrome with a combination of Hodgkin’s lymphoma and anti-NMDA encephalitis, probably triggered by the reactivation of the Epstein–Barr virus with a fatal outcome. The second patient was diagnosed with autoimmune anti-LGI1 limbic encephalitis, and the third patient was seronegative to the available immunological antigens. The authors note the need to rethink the concept of ‘encephalitis of unknown aetiology’ and its transformation into ‘autoimmune encephalitis’ with the immunological diagnosis of three antigens (NMDA, LGI1, CASPR2). Considering the rarity of the disease, the high probability of initial admission to an infectious diseases or psychiatric hospital, it is worthwhile to explore this problem more widely at various research forums and to create a comprehensive, interdisciplinary approach to the diagnosis of this disease in the Russian Federation.