Autistic Regression Sequelae or Relapse for NMDA Receptor Antibody Encephalitis

Objective To highlight a pediatric presentation of autistic regression secondary to relapsing NMDA receptor antibody encephalitis (NMDARAE) post-HSV infection. Background It is reported that 30% patients develop antibodies (NMDARA) after HSV Encephalitis. Previous studies have demonstrated significant association between prior HSV-1 infection and NMDARAE, diagnosis often overlooked due diverse neurological manifestations. Design/Methods NA. Results This case highlights 5-year-old female presenting with fever refractory status epilepticus, was diagnosed Encephalitis requiring prolonged hospitalization. At discharge she had insomnia, mutism, dyskinetic movements, atonic seizures, developmental regression. 3 months post-discharge EEG exhibited multiple generalized myoclonic, myoclonic tonic, MRI brain right temporal lobe encephalomalacia immunologic workup demonstrating positive serum CSF NMDARA. She underwent treatment intravenous steroids followed by plasmapheresis then rituximab an improved clinical response seizure control at 6 months. 9 months, displayed behavioral changes ADHD Workup for NMDARA in the (18 post-presentation) showed diffuse epileptiform discharges activated during sleep. treated rituximab. follow-up, social interaction, sleep, persistence some features. Conclusions About 90% NMDARE present prominent manifestations, challenges differentiating from psychiatric diseases. Relapse 12-24% cases associated delayed gender. NMDARAE relapse underreported, especially regression, as our case. In conclusion, given overlapping subtle symptoms, it crucial recognize varying presentations early effective better outcome.