Ovarian Teratoma presenting as Anti NMDAR Antibody Negative Limbic Encephalitis.

Anti NMDA receptor (NMDAR) antibody mediated limbic encephalitis is the most common type of autoimmune encephalitis. Nearly half of the females presenting with anti NMDAR encephalitis have associated ovarian teratoma. Almost all of them have positive anti NMDAR antibody. Here we present a case of ovarian teratoma associated limbic encephalitis, with clinical picture typical of anti NMDAR mediated encephalitis, who was found to be negative for the antiNMDAR antibody. Clinicians should not defer from investigating a case of suspected anti NMDAR encephalitis for ovarian teratoma, even if antibody is negative.