Adolescent with acute psychosis due to anti-N-methyl-D-aspartate receptor encephalitis: successful recovery

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is a relatively new autoimmune disorder of the central nervous system. We report the first case of anti-NMDAR autoimmune encephalitis combined with anti-voltage-gated potassium channel (anti-VGKC) antibodies in Lithuania in a 16-year-old girl. The patient was admitted to psychiatry unit because of an acute psychotic episode. She was unsuccessfully treated with antipsychotics, and electroconvulsive therapy was initiated because of her rapidly deteriorating condition. Electroconvulsive therapy improved the patient’s condition even before the initiation of immunomodulatory therapy. The abrupt onset, atypical and severe course of psychosis, poor response to antipsychotic treatment, and signs of flu-like prodromal period led to the search of non-psychiatric causes. Although with considerable delay, she was screened for an autoimmune encephalitis. Positive anti-NMDA receptor antibodies were found in the cerebrospinal fluid, but not in serum. In addition, serum was found positive for antinuclear antibodies and anti-VGKC antibodies but negative for CASPR2 and LGI1 antibodies. The girl was treated with intravenous immunoglobulin and methylprednisolone with satisfactory response, although infrequent orofacial movements, emotional lability, and learning deficits remained upon discharge. The reported case suggests that multiple antibodies could be present, and that electroconvulsive therapy may have a role in symptomatic treatment of autoimmune encephalitis.