Anti-NMDA antibody autoimmune encephalitis post-HSV encephalitis: A rare case report

Abstract

Introduction: Autoimmune encephalitis is a group of neuropsychiatric disorder in which antibodies interact directly to their target antigen and produce neuronal dysfunction. Generally herpes simplex encephalitis is a monophasic illness although in few patients neurological worsening can develop some weeks later. This worsening is generally due to autoimmune encephalitis after herpes simplex encephalitis (AEaHSE). Case Report: We report an interesting case report of 67 years old female patient who initially was diagnosed to have herpes simplex virus (HSV) encephalitis, showed improvement in her clinical status followed subsequently by deterioration in cognitive status. Anti-N-methyl-D-aspartate (NMDA) antibody was positive in cerebrospinal fluid (CSF) and serum. The patient was managed with intravenous immunoglobulin (IVIG) and subsequently showed improvement in her clinical state. Conclusion: The discovery and clinical application of anti-NMDA receptor antibodies has helped to define the mechanism behind immune-based relapse of herpes simplex virus encephalitis (HSVE). This case illustrates the usefulness of testing for anti-NMDA receptor antibodies following worsening few weeks after treatment of herpes simplex encephalitis.