[Recent concept of limbic encephalitis: progress in anti-NMDA receptor encephalitis]

Patients with limbic encephalitis usually present with rapidly progressive short-term memory deficits, psychiatric symptoms, and seizures. The recent concept of limbic encephalitis has been expanded. Especially, various types of autoimmune limbic encephalitis are associated with autoantibodies of intracellular or cell membrane antigens. Sine autoimmune limbic encephalitis is also associated with some types of tumors, it has also an aspect of paraneoplastic syndrome. Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis is a new category of treatment-responsive limbic encephalitis associated with anti-NMDAR antibodies, which is the most frequent autoantibody to cell membrane antigen. The autoantibodies are detected in the CSF and serum of young women with ovarian teratoma, who typically develop schizophrenia-like psychiatric symptoms. There is a highly characteristics syndrome evolving in 5 stages; the prodromal, psychotic, unresponsive, hyperkinetic, and gradual recovery phases. The hyperkinetic phase is the most prolonged and crucial. This disorder is usually severe and can be fatal, but it is potentially reversible. Although the pathogenesis remains unclear, this disorder is considered to be the autoantibody-mediated encephalitis. This review focuses in the recent concept of limbic encephalitis and clinical characteristics of anti-NMDA receptor encephalitis.