title: Consensus classification of posterior cortical atrophy.
abstract: BACKGROUND
  A classification framework for posterior cortical atrophy (PCA) is proposed to improve the uniformity of definition of the syndrome in a variety of research settings.
  
  
  METHODS
  Consensus statements about PCA were developed through a detailed literature review, the formation of an international multidisciplinary working party which convened on four occasions, and a Web-based quantitative survey regarding symptom frequency and the conceptualization of PCA.
  
  
  RESULTS
  A three-level classification framework for PCA is described comprising both syndrome- and disease-level descriptions. Classification level 1 (PCA) defines the core clinical, cognitive, and neuroimaging features and exclusion criteria of the clinico-radiological syndrome. Classification level 2 (PCA-pure, PCA-plus) establishes whether, in addition to the core PCA syndrome, the core features of any other neurodegenerative syndromes are present. Classification level 3 (PCA attributable to AD [PCA-AD], Lewy body disease [PCA-LBD], corticobasal degeneration [PCA-CBD], prion disease [PCA-prion]) provides a more formal determination of the underlying cause of the PCA syndrome, based on available pathophysiological biomarker evidence. The issue of additional syndrome-level descriptors is discussed in relation to the challenges of defining stages of syndrome severity and characterizing phenotypic heterogeneity within the PCA spectrum.
  
  
  CONCLUSIONS
  There was strong agreement regarding the definition of the core clinico-radiological syndrome, meaning that the current consensus statement should be regarded as a refinement, development, and extension of previous single-center PCA criteria rather than any wholesale alteration or redescription of the syndrome. The framework and terminology may facilitate the interpretation of research data across studies, be applicable across a broad range of research scenarios (e.g., behavioral interventions, pharmacological trials), and provide a foundation for future collaborative work.
authors.affiliation: Dementia Research Centre, UCL Institute of Neurology, London, UK. Electronic address: s.crutch@ucl.ac.uk.
authors.forename: Sebastian J
authors.initials: SJ
authors.lastname: Crutch
authors.affiliation: Dementia Research Centre, UCL Institute of Neurology, London, UK.
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Schott
authors.affiliation: Department of Neurology, Memory & Aging Center, University of California, San Francisco, San Francisco, CA, USA.
authors.forename: Gil D
authors.initials: GD
authors.lastname: Rabinovici
authors.affiliation: Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA.
authors.forename: Melissa
authors.initials: M
authors.lastname: Murray
authors.affiliation: Cerebral Function Unit, Greater Manchester Neuroscience Centre, Salford Royal NHS Foundation Trust, Salford, UK; Institute of Brain, Behaviour and Mental Health, University of Manchester, Manchester, UK.
authors.forename: Julie S
authors.initials: JS
authors.lastname: Snowden
authors.affiliation: Department of Neurology, VU University Medical Centre, Amsterdam Neuroscience, Amsterdam, The Netherlands; Alzheimer Center, VU University Medical Centre, Amsterdam Neuroscience, Amsterdam, The Netherlands.
authors.forename: Wiesje M
authors.initials: WM
authors.lastname: van der Flier
authors.affiliation: Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
authors.forename: Bradford C
authors.initials: BC
authors.lastname: Dickerson
authors.affiliation: Laboratory for Cognitive Neurology, Department of Neurosciences, KU Leuven, Leuven, Belgium.
authors.forename: Rik
authors.initials: R
authors.lastname: Vandenberghe
authors.affiliation: Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
authors.forename: Samrah
authors.initials: S
authors.lastname: Ahmed
authors.affiliation: Human Cognitive Neuroscience, School of Philosophy, Psychology and Language Sciences, University of Edinburgh, Edinburgh, UK.
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Bak
authors.affiliation: Department of Neurology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Bradley F
authors.initials: BF
authors.lastname: Boeve
authors.affiliation: Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
authors.forename: Christopher
authors.initials: C
authors.lastname: Butler
authors.affiliation: Center for Cognitive Neuroscience, Vita-Salute San Raffaele University, Milan, Italy.
authors.forename: Stefano F
authors.initials: SF
authors.lastname: Cappa
authors.affiliation: INSERM U 1106, Institut des Neurosciences des Systèmes, Aix Marseille Université, Marseilles, France.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Ceccaldi
authors.affiliation: Departamento de Clínica Médica, Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Leonardo Cruz
authors.initials: LC
authors.lastname: de Souza
authors.affiliation: Institute for Memory and Alzheimer's Disease, UMR-S975, Salpêtrière Hospital, Pierre & Marie Curie University, Paris, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Dubois
authors.affiliation: Aix-Marseille Université, INSERM, Institut de Neurosciences des Systèmes, Marseille, France; AP-HM Hôpitaux de la Timone, Service de Neurologie et Neuropsychologie, Marseille, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Felician
authors.affiliation: Department of Neurosciences, University of California, San Diego, San Diego, USA.
authors.forename: Douglas
authors.initials: D
authors.lastname: Galasko
authors.affiliation: Department of Neurology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Graff-Radford
authors.affiliation: Department of Neurology, Mayo Clinic, Jacksonville, FL, USA.
authors.forename: Neill R
authors.initials: NR
authors.lastname: Graff-Radford
authors.affiliation: Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, USA; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, USA.
authors.forename: Patrick R
authors.initials: PR
authors.lastname: Hof
authors.affiliation: Clinical and Research Memory Center of Lyon, Hospices Civils de Lyon, INSERM U1028, CNRS UMR5292, University of Lyon, Lyon, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Krolak-Salmon
authors.affiliation: Dementia Research Centre, UCL Institute of Neurology, London, UK; Department of Neurology, Memory & Aging Center, University of California, San Francisco, San Francisco, CA, USA.
authors.forename: Manja
authors.initials: M
authors.lastname: Lehmann
authors.affiliation: Department of Neurology, Regional Memory Centre (CMRR), CHU Besançon, Besançon, France.
authors.forename: Eloi
authors.initials: E
authors.lastname: Magnin
authors.affiliation: Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.
authors.forename: Mario F
authors.initials: MF
authors.lastname: Mendez
authors.affiliation: Cognitive Neurology and Neurodegeneration Group, German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Nestor
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Chiadi U
authors.initials: CU
authors.lastname: Onyike
authors.affiliation: Department of Neurology, University of Colorado School of Medicine, Aurora, CO, USA; Department of Ophthalmology, University of Colorado School of Medicine, Aurora, CO, USA.
authors.forename: Victoria S
authors.initials: VS
authors.lastname: Pelak
authors.affiliation: Department of Neurology, VU University Medical Centre, Amsterdam Neuroscience, Amsterdam, The Netherlands; Alzheimer Center, VU University Medical Centre, Amsterdam Neuroscience, Amsterdam, The Netherlands.
authors.forename: Yolande
authors.initials: Y
authors.lastname: Pijnenburg
authors.affiliation: Dementia Research Centre, UCL Institute of Neurology, London, UK.
authors.forename: Silvia
authors.initials: S
authors.lastname: Primativo
authors.affiliation: Dementia Research Centre, UCL Institute of Neurology, London, UK.
authors.forename: Martin N
authors.initials: MN
authors.lastname: Rossor
authors.affiliation: Dementia Research Centre, UCL Institute of Neurology, London, UK.
authors.forename: Natalie S
authors.initials: NS
authors.lastname: Ryan
authors.affiliation: Department of Neurology, VU University Medical Centre, Amsterdam Neuroscience, Amsterdam, The Netherlands; Alzheimer Center, VU University Medical Centre, Amsterdam Neuroscience, Amsterdam, The Netherlands.
authors.forename: Philip
authors.initials: P
authors.lastname: Scheltens
authors.affiliation: Dementia Research Centre, UCL Institute of Neurology, London, UK.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Shakespeare
authors.affiliation: Dementia Research Centre, UCL Institute of Neurology, London, UK; Memory Disorders Unit, Neurology Department, University Hospital Virgen del Rocio, Seville, Spain.
authors.forename: Aida
authors.initials: A
authors.lastname: Suárez González
authors.affiliation: Division of Neurology, University Health Network Memory Clinic, University of Toronto, Toronto, Ontario, Canada.
authors.forename: David F
authors.initials: DF
authors.lastname: Tang-Wai
authors.affiliation: Dementia Research Centre, UCL Institute of Neurology, London, UK.
authors.forename: Keir X X
authors.initials: KXX
authors.lastname: Yong
authors.affiliation: Medical and Scientific Relations, Alzheimer's Association, Chicago, IL, USA.
authors.forename: Maria
authors.initials: M
authors.lastname: Carrillo
authors.affiliation: Dementia Research Centre, UCL Institute of Neurology, London, UK.
authors.forename: Nick C
authors.initials: NC
authors.lastname: Fox
mesh_terms: D001921:Brain / Q000000981:diagnostic imaging; D001927:Brain Diseases / Q000145:classification* / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000523:psychology; D006801:Humans
keywords: Alzheimer's disease; Biomarker; Clinico-radiological syndrome; Pathophysiology; Posterior cortical atrophy