Anti-N-Methyl D-Aspartate (NMDA) receptor encephalitis after herpes virus meningoencephalitis: a case report

Abstract

Anti-N-methyl D-aspartate (NMDA) receptor encephalitis is an autoimmune disease of the central nervous system characterized by psychiatric and neurological symptoms. This pathology may be associated with paraneoplastic syndrome and viral infections, especially the Herpes simplex virus. However, a considerable number of cases may remain without an identifiable triggering factor. We report the case of a 17-year-old girl who presented with headache, fever and meningeal signs. Cerebrospinal fluid (CSF) analysis showed a herpes virus infection. After treatment using Acyclovir for 21 days, the patient showed improvement in neurological symptoms. However, new symptoms were evidenced: behavioral alterations, aggressiveness, delirium, hallucinations, thoughts of self-extermination, catatonia and cognitive impairment. Psychiatric evaluation suggested the use of an atypical, but no beneficial effect was observed. Considering the refractoriness of the condition, a new CSF analysis showed positivity for the NMDA antibody. Thus, the patient underwent immunomodulatory therapy with Methylprednisolone for five days, obtaining little behavioral improvement. Due to subsequent dysautonomia and seizures, the patient underwent plasmapheresis for five days, obtaining significant improvement in symptoms. The present case emphasizes the importance of the differential diagnosis of NMDA receptor encephalitis after infections of the central nervous system that present psychiatric symptoms.