Analysing Triggers for Anti-NMDA-Receptor Encephalitis Including Herpes Simplex Virus Encephalitis and Ovarian Teratoma: Results from the Queensland Autoimmune Encephalitis Cohort.

Abstract

INTRODUCTION\nAnti-N-methyl-D-Aspartate-Receptor (anti-NMDA-R) encephalitis is a complex autoimmune neuropsychiatric syndrome. Although initially associated with ovarian teratoma, subsequent studies have demonstrated that anti-NMDA-R encephalitis may occur without an identifiable cause or be triggered by viral infection of the central nervous system such as herpes simplex virus encephalitis (HSVE). This study will present details from a Queensland cohort analysing triggering events in patients with anti-NMDA-R encephalitis in an Australian context.\n\n\nMETHODOLOGY\nThe authors identified patients with anti-NMDA-R encephalitis diagnosed and managed through public hospitals in Queensland, Australia between 2010 and the end of 2019. Data collected included demographics, clinical presentation, investigation results, management and outcome measurements.\n\n\nRESULTS\nThirty-one cases of anti-NMDA-R encephalitis were included in the study. Three cases of anti-NMDA-R encephalitis were triggered by prior HSVE, five cases were associated with ovarian teratoma and twenty-three cases had no identifiable trigger. There were an additional three cases in which anti-NMDA receptor antibodies were present in the context of other disease states but where the patient didn t develop anti-NMDA-R encephalitis. Cases triggered by HSVE or associated with ovarian teratoma experienced a more severe disease course compared to cases with no identifiable trigger. All groups responded to immunosuppressive or immunomodulatory therapy. Analysis of clinical characteristics revealed a complex heterogeneous syndrome with some variability between groups.\n\n\nCONCLUSION\nIn this cohort, the number of cases of anti-NMDA-R encephalitis triggered by HSVE is comparable to those triggered by ovarian teratoma. However, the majority of cases of anti-NMDA-R encephalitis had no identifiable trigger or associated disease process. This article is protected by copyright. All rights reserved.