title: Pediatric anti-N-methyl-D-aspartate receptor encephalitis-clinical analysis and novel findings in a series of 20 patients.
abstract: OBJECTIVE
  To report the clinical features of 20 pediatric patients with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis.
  
  
  METHODS
  Review of clinical data, long-term follow-up, and immunologic studies performed in a single center in Spain in the last 4 years.
  
  
  RESULTS
  The median age of the patients was 13 years (range, 8 months-18 years), 70% were female. In 12 patients (60%), the initial symptoms were neurologic, usually dyskinesias or seizures, and in the other 40% psychiatric. One month into the disease, all patients had involuntary movements and alterations of behavior and speech. All patients received steroids, intravenous immunoglobulin or plasma exchange, and 7 rituximab or cyclophosphamide. With a median follow up of 17.5 months, 85% had substantial recovery, 10% moderate or severe deficits, and 1 died. Three patients had previous episodes compatible with anti-NMDAR encephalitis, 2 of them with additional relapses after the diagnosis of the disorder. Ovarian teratoma was identified in 2 patients, 1 at onset of encephalitis and the other 1 year later. Two novel observations (1 patient each) include, the identification of an electroencephalographic pattern ("extreme delta brush") considered characteristic of this disorder, and the development of anti-NMDAR encephalitis as post herpes simplex encephalitis choreoathetosis.
  
  
  CONCLUSIONS
  The initial symptoms of pediatric anti-NMDAR encephalitis vary from those of the adults (more neurologic and less psychiatric in children), the development of a mono-symptomatic illness is extremely rare (except in relapses), and most patients respond to treatment. Our study suggests a link between post herpes simplex encephalitis choreoathetosis and anti-NMDAR encephalitis.
authors.affiliation: Institut d'Investigació Biomèdica August Pi i Sunyer (IDIBAPS), Service of Neurology, Hospital Clínic, University of Barcelona, Barcelona, Spain.
authors.forename: Thaís
authors.initials: T
authors.lastname: Armangue
authors.forename: Maarten J
authors.initials: MJ
authors.lastname: Titulaer
authors.forename: Ignacio
authors.initials: I
authors.lastname: Málaga
authors.forename: Luis
authors.initials: L
authors.lastname: Bataller
authors.forename: Iñigo
authors.initials: I
authors.lastname: Gabilondo
authors.forename: Francesc
authors.initials: F
authors.lastname: Graus
authors.forename: Josep
authors.initials: J
authors.lastname: Dalmau
mesh_terms: D000293:Adolescent; D060426:Anti-N-Methyl-D-Aspartate Receptor Encephalitis / Q000097:blood* / Q000175:diagnosis*; D001921:Brain / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007167:Immunotherapy / Q000379:methods; D007223:Infant; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D010372:Pediatrics / Q000379:methods; D013030:Spain; D013997:Time Factors; D016896:Treatment Outcome