Non-paraneoplastic Anti-NMDAR Encephalitis: First Confirmed Adult Case Report in Latvia

Abstract

Anti-NMDAR (Anti-N-Methyl-D-aspartic acid) encephalitis is a rare autoimmune condition mainly affecting young women. It is associated with an underlying tumor in about 50% of reported cases. Antibodies directed against the GluN1 subunit of the NMDA receptor are responsible for the disease pathogenesis and their detection in the patient's serum and cerebrospinal fluid are required to make a definite diagnosis. Classical clinical presentation consists of flu-like symptoms, followed by psychiatric disturbances and impaired consciousness, epileptic seizures and movement disorders. During the past decade, it has become an emerging area of research and discussion as more than 1,000 cases have been reported since the first description of this specific disease entity in 2007. Despite a rather typical clinical course it is frequently diagnosed and treated with a delay up to many months. Overall prognosis tends to be favorable. However, it strongly depends on early diagnosis and rapid treatment initiation. While diagnostic criteria for probable and definite anti-NMDAR encephalitis have been proposed, there are no evidence based guidelines for specific treatment strategies. Glucocorticoids, plasma exchange and IVIG are generally used as 1st line treatment, in patients who do not respond, 2nd line treatment with Cyclophosphamide or Rituximab is used. We report a case of a confirmed non-paraneoplastic anti-NMDAR encephalitis with a rather classical manifestation in a Latvian woman who is first hospitalized in a psychiatric clinic then transferred to an ICU (intensive care unit), treated with glucocorticoids, plasma exchange and later Cyclophosphamide with a good outcome.