title: Evaluation of the new consensus criteria for the diagnosis of primary progressive aphasia using fluorodeoxyglucose positron emission tomography.
abstract: BACKGROUND
  New consensus criteria have been proposed to classify primary progressive aphasia (PPA) into three variants: agrammatic, semantic, and logopenic. Some studies have subsequently addressed the usefulness of these criteria, with controversial results. We aimed to determine the correlation between the clinical diagnosis according to the new criteria and brain topography in (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET).
  
  
  METHODS
  Patients meeting the PPA criteria were prospectively recruited in a single center during a period of 18 months. They were clinically classified according to the new criteria and underwent FDG-PET. The cerebral metabolism of each patient was compared to a healthy control group using statistical parametric mapping. The expected variant according to the analysis of PET imaging was compared with the clinical diagnosis using the consensus criteria.
  
  
  RESULTS
  32 patients were included. 90% of them fulfilled the consensus criteria and could be classified into one of the three clinical variants. The correlation with the cerebral metabolism was high: the kappa index was 0.91 in the agrammatic variant, 0.71 in the semantic variant, and 0.74 in the logopenic variant.
  
  
  CONCLUSIONS
  A high correlation with the diagnosis obtained using FDG-PET was found. However, an overdiagnosis of the logopenic variant was observed. These results support the use of the new criteria, but some modifications or complementary studies may still be necessary.
authors.affiliation: Department of Neurology, Hospital Clinico San Carlos, Health Research Institute 'San Carlos' (IdISCC), Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: Jordi A
authors.initials: JA
authors.lastname: Matias-Guiu
authors.forename: Maria Nieves
authors.initials: MN
authors.lastname: Cabrera-Martín
authors.forename: Rocío
authors.initials: R
authors.lastname: García-Ramos
authors.forename: Teresa
authors.initials: T
authors.lastname: Moreno-Ramos
authors.forename: Maria
authors.initials: M
authors.lastname: Valles-Salgado
authors.forename: José Luis
authors.initials: JL
authors.lastname: Carreras
authors.forename: Jorge
authors.initials: J
authors.lastname: Matias-Guiu
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018888:Aphasia, Primary Progressive / Q000175:diagnosis / Q000000981:diagnostic imaging; D015331:Cohort Studies; D019788:Fluorodeoxyglucose F18; D005625:Frontal Lobe / Q000000981:diagnostic imaging; D010296:Parietal Lobe / Q000000981:diagnostic imaging; D049268:Positron-Emission Tomography; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D013702:Temporal Lobe / Q000000981:diagnostic imaging; D003245:Consensus Statements as Topic
chemical_list: D019788:Fluorodeoxyglucose F18; D019275:Radiopharmaceuticals