N-methyl-D-aspartate receptor antibodies in pediatric dyskinetic encephalitis lethargica

Ann Neurol. 2009 Nov;66(5):704-9. doi: 10.1002/ana.21807.


Encephalitis lethargica (EL) describes an encephalitis with psychiatric, sleep, and extrapyramidal movement disorders. Dyskinetic and parkinsonian forms have been described. EL shares clinical features with the anti-N-methyl-D-aspartate receptor (NMDAR-Ab) encephalitis. We studied 20 sera from pediatric patients with contemporary EL. Ten sera (from 2 males and 8 females, aged 1.3-13 years) and 6/6 cerebrospinal fluid samples were positive for NMDAR-Ab. NMDAR-Ab-positive patients had dyskinesias, agitation, seizures, and insomnia, whereas parkinsonism and somnolence dominated in the NMDAR-Ab-negative children. We were unable to identify any tumors. The dyskinetic form of EL is an NMDAR-Ab encephalitis and can affect very young children.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Autoantibodies / biosynthesis*
  • Autoantibodies / metabolism
  • Binding Sites, Antibody
  • Child
  • Child, Preschool
  • Female
  • Humans
  • Infant
  • Male
  • Neurons / immunology
  • Parkinson Disease, Postencephalitic / cerebrospinal fluid
  • Parkinson Disease, Postencephalitic / diagnosis
  • Parkinson Disease, Postencephalitic / immunology*
  • Phenotype
  • Potassium Channels, Voltage-Gated / immunology
  • Receptors, N-Methyl-D-Aspartate / immunology*
  • Receptors, N-Methyl-D-Aspartate / metabolism


  • Autoantibodies
  • Potassium Channels, Voltage-Gated
  • Receptors, N-Methyl-D-Aspartate