title: Anti-NMDA receptor encephalitis presenting with imaging findings and clinical features mimicking Rasmussen syndrome.
abstract: BACKGROUND
  Antibody mediated anti-N-methyl-d-aspartate (NMDA) receptor encephalitis is a recently reported diagnosis of clinical importance. Recognition of the syndrome, especially in pediatric populations, is difficult and often undiagnosed and/or confused with neurological disorders with similar clinical features.
  
  
  RESULTS
  We report a case of an 11 year old female with explosive-onset epilepsy and predominantly unilateral frontal lobe abnormalities on magnetic resonance imaging (MRI) and fluorodeoxyglucose positron emission tomography (FDG-PET) neuroimaging. A diagnosis of Rasmussen syndrome (RS) was considered. Cerebrospinal fluid analysis revealed strong positivity for NMDA receptor antibodies. Screening for occult ovarian teratoma with computed tomography (CT) and MRI initially did not demonstrate associated tumor. Treatment with steroids and plasma exchange improved her clinical course and subsequent MRI showed resolution.
  
  
  CONCLUSIONS
  NMDA receptor encephalitis has variable neuroimaging manifestations, and can mimic other entities. We emphasize the clinical syndrome of NMDA receptor encephalitis and consideration of the diagnosis in evaluating a child with explosive-onset epilepsy, unilateral imaging abnormalities, and neurocognitive decline.
authors.affiliation: Department of Pediatrics, Division of Child Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA.
authors.forename: Hansel
authors.initials: H
authors.lastname: Greiner
authors.forename: James L
authors.initials: JL
authors.lastname: Leach
authors.forename: Ki-Hyeong
authors.initials: KH
authors.lastname: Lee
authors.forename: Darcy A
authors.initials: DA
authors.lastname: Krueger
mesh_terms: D000906:Antibodies / Q000097:blood*; D002648:Child; D004569:Electroencephalography; D004660:Encephalitis / Q000175:diagnosis* / Q000276:immunology* / Q000503:physiopathology*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D049268:Positron-Emission Tomography / Q000379:methods; D016194:Receptors, N-Methyl-D-Aspartate / Q000276:immunology*; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D000906:Antibodies; D016194:Receptors, N-Methyl-D-Aspartate; D019788:Fluorodeoxyglucose F18