title: Creutzfeldt-Jakob disease mimicking autoimmune encephalitis with CASPR2 antibodies.
abstract: BACKGROUND
  Differential diagnosis of severe progressive dementia includes a wide spectrum of inflammatory and neurodegenerative diseases. Particularly challenging is the differentiation of potentially treatable autoimmune encephalitis and Creutzfeldt-Jakob disease. Such a coincidence may indeed complicate the correct diagnosis and influence subsequent treatment.
  
  
  METHODS
  A 75-year-old woman was admitted due to rapid progressive cognitive impairment. Her husband observed a temporal disorientation and confusion. The initial neurological examination and an extensive neuropsychological evaluation showed significant impairments in almost all tested cognitive domains. All other neurological functions including motor, sensory and coordinative function were intact. Initial diagnostics included EEG, MRI and lumbar puncture with unspecific results. Complementary blood testing revealed a positive result for antineural antibodies to Contactin-associated protein 2 (CASPR2) and the patient received treatment for CASPR2 autoimmune encephalitis. Further symptoms and results, including 14-3-3 proteins, led to suspected Creutzfeldt-Jakob disease. The postmortem examination supported the diagnosis of a definitive Creutzfeldt-Jakob disease.
  
  
  CONCLUSIONS
  One could argue that global screening for antineural antibodies may lead to a false diagnosis triggering intense and potentially dangerous procedures. We believe, however, that potentially treatable causes of dementia should aggressively sought out and subsequently treated in an attempt to curtail the course of disease and ultimately reduce the rate of mortality.
authors.affiliation: Department of Neurology, Evangelisches Krankenhaus, Burgsteig 13, Bielefeld, 33617, Germany. frederic.zuhorn@evkb.de.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Zuhorn
authors.affiliation: Department of Neurology, Evangelisches Krankenhaus, Burgsteig 13, Bielefeld, 33617, Germany. almut.huebenthal@evkb.de.
authors.forename: Almut
authors.initials: A
authors.lastname: Hübenthal
authors.affiliation: Department of Neurology, Evangelisches Krankenhaus, Burgsteig 13, Bielefeld, 33617, Germany. andreas.rogalewski@evkb.de.
authors.forename: Andreas
authors.initials: A
authors.lastname: Rogalewski
authors.affiliation: Epilepsy Center Bethel, Krankenhaus Mara, Maraweg 17-21, Bielefeld, 33617, Germany. muejgan.dogan@mara.de.
authors.forename: Müjgan
authors.initials: M
authors.lastname: Dogan Onugoren
authors.affiliation: Institute of Neuropathology, Universitätsklinikum Hamburg-Eppendorf, Martinistraße 52, Hamburg, 20246, Germany. m.glatzel@uke.de.
authors.forename: Markus
authors.initials: M
authors.lastname: Glatzel
authors.affiliation: Epilepsy Center Bethel, Krankenhaus Mara, Maraweg 17-21, Bielefeld, 33617, Germany. christian.bien@mara.de.
authors.forename: Christian G
authors.initials: CG
authors.lastname: Bien
authors.affiliation: Department of Neurology, Evangelisches Krankenhaus, Burgsteig 13, Bielefeld, 33617, Germany. wolf.schaebitz@evkb.de.
authors.forename: Wolf-Rüdiger
authors.initials: WR
authors.lastname: Schäbitz
mesh_terms: D000368:Aged; D001323:Autoantibodies; D007562:Creutzfeldt-Jakob Syndrome / Q000175:diagnosis* / Q000276:immunology*; D003937:Diagnosis, Differential; D004660:Encephalitis / Q000175:diagnosis / Q000276:immunology; D005260:Female; D050031:Hashimoto Disease / Q000175:diagnosis / Q000276:immunology; D006801:Humans; D008565:Membrane Proteins / Q000276:immunology*; D009419:Nerve Tissue Proteins / Q000276:immunology*
chemical_list: D001323:Autoantibodies; C403049:CNTNAP2 protein, human; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins