A Case series with comparative analysis of children and young adults with Anti-N-Methyl-D-Aspartate Receptor Encephalitis (P5-5.004)

Objective: To compare clinical presentation of 5 patients of various age groups with Anti-N-Methyl-D-Aspartate (NMDA) Receptor Encephalitis Background: Anti-NMDA-receptor antibody encephalitis is a treatable neurological condition hypothesized to be secondary to immune response initiated by an ovarian tumor or a non-specific infectious etiology. The immune mediated trigger produces antibodies that cross the compromised blood brain barrier where they interact with NR1/NR2 subunits of NMDA receptor resulting in encephalitis. Clinical presentation can vary according to the age and can include psychiatric symptoms, cognitive impairment, seizures, autonomic instability, and movement disorders. Design/Methods: Medical chart review of patients seen in a university hospital with varied presentations and subsequent diagnosis of Anti-NMDA-receptor antibody encephalitis Results: We describe 5 cases of Anti-NMDA-receptor antibody encephalitis seen at a university hospital between 2016 and 2022. Three were children under 5 years of age (youngest is 2.5 months) with abnormal choreo-athetoid movements and two were young women with psychiatric symptoms. Two of the infants had a preceding infectious exposure while both the young women had ovarian cysts. Except one infant, all cases had seizures during their disease course. All cases had CSF antibody positivity except one. Management included high dose IV methyl prednisolone with good response, followed by IVIG and/or Rituximab infusions in resistant cases. Conclusions: Clinicians should have high suspicion for Anti-NMDA-receptor antibody encephalitis in patients presenting with abnormal movements or nonspecific sudden onset psychological symptoms in the presence or absence of a preceding infectious prodrome. Aggressive testing with serum and CSF NMDA antibody titers is warranted when EEG is not consistent with seizures as Anti-NMDA-receptor antibody encephalitis is a treatable neurological condition with high morbidity and mortality if left untreated. Disclosure: Dr. Vasireddy has nothing to disclose. Qutubuddin Khan has nothing to disclose. Dr. Guduru has nothing to disclose.