We present a case of a 16-year-old boy with Klinefelter syndrome who presented with a syndrome of impaired alertness, orofacial dyskinesias, choreiform movements, epileptic seizures, and autonomic instability, pointing to a diagnosis of anti-N-methyl-Daspartate (anti-NMDA) receptor antibody encephalitis.
LancasterEMartinez-HenandezEDalmauJ. Encephalitis and antibodies to synaptic and neuronal cell surface proteins. Neurology. 2011;77:179–189.
2.
DalmauJGleichmanAJHughesEG. Anti-NMDA-receptor encephalitis: case series and analysis of the effects of antibodies. Lancet Neurol. 2008;7:1091–1098.
3.
FloranceNRDavisRLLamC. Anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis in children and adolescents. Ann Neurol. 2009;66:11–18.
4.
TitulaerMJMcCrackenLGabilondoI. Treatment and prognostic factors for long-term outcome in patients with anti-NMDA receptor encephalitis: an observational cohort study. Lancet Neurol. 2012;12:157–165.
5.
VölklTMLangerTAignerT. Klinefelter syndrome and mediastinal germ cell tumors. Am J Med Genet A. 2006;140:471–481.
6.
PeeryHEDayGSDunnS. Anti-NMDA receptor encephalitis. The disorder, the diagnosis and the immunobiology. Autoimmun Rev. 2012;11:863–872.
7.
DalmauJTüzünEWuHY. Paraneoplastic anti-N-methyl-d-aspartate receptor encephalitis associated with ovarian teratoma. Ann Neurol. 2007;61:25–36.
8.
ChapmanMRVauseHE. Anti-NMDA receptor encephalitis: diagnosis, psychiatric presentation and treatment. Am J Psychiatry. 2011;168:245–251.
DalmauJLancasterEMartinez-HernandezE. Clinical experience and laboratory investigations in patients with anti-NMDAR encephalitis. Lancet Neurol. 2010;10:63–74.
