title: The semantic variant of primary progressive aphasia: clinical and neuroimaging evidence in single subjects.
abstract: OBJECTIVE
  We present a clinical-neuroimaging study in a series of patients with a clinical diagnosis of semantic variant of primary progressive aphasia (svPPA), with the aim to provide clinical-functional correlations of the cognitive and behavioral manifestations at the single-subject level.
  
  
  METHODS
  We performed neuropsychological investigations, 18F-FDG-PET single-subject and group analysis, with an optimized SPM voxel-based approach, and correlation analyses. A measurement of white matter integrity by means of diffusion tensor imaging (DTI) was also available for a subgroup of patients.
  
  
  RESULTS
  Cognitive assessment confirmed the presence of typical semantic memory deficits in all patients, with a relative sparing of executive, attentional, visuo-constructional, and episodic memory domains. 18F-FDG-PET showed a consistent pattern of cerebral hypometabolism across all patients, which correlated with performance in semantic memory tasks. In addition, a majority of patients also presented with behavioral disturbances associated with metabolic dysfunction in limbic structures. In a subgroup of cases the DTI analysis showed FA abnormalities in the inferior longitudinal and uncinate fasciculi.
  
  
  CONCLUSIONS
  Each svPPA individual had functional derangement involving an extended, connected system within the left temporal lobe, a crucial part of the verbal semantic network, as well as an involvement of limbic structures. The latter was associated with behavioral manifestations and extended beyond the area of atrophy shown by CT scan.
  
  
  CONCLUSIONS
  Single-subject 18F-FDG-PET analysis can account for both cognitive and behavioral alterations in svPPA. This provides useful support to the clinical diagnosis.
authors.affiliation: Vita-Salute San Raffaele University and Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Iaccarino
authors.affiliation: Vita-Salute San Raffaele University and Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy; CERMAC, Vita-Salute San Raffaele University, Milan, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Crespi
authors.affiliation: Istituto di Bioimmagini e Fisiologia Molecolare C.N.R., Segrate, Italy.
authors.forename: Pasquale Anthony
authors.initials: PA
authors.lastname: Della Rosa
authors.affiliation: Istituto Universitario degli Studi Superiori-IUSS, Pavia, Italy.
authors.forename: Eleonora
authors.initials: E
authors.lastname: Catricalà
authors.affiliation: Istituto Universitario degli Studi Superiori-IUSS, Pavia, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Guidi
authors.affiliation: Department of Clinical Neurosciences, San Raffaele Hospital, Milan, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Marcone
authors.affiliation: IRCCS Foundation "Carlo Besta" Neurological Institute, Milan, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Tagliavini
authors.affiliation: Departments of Neurology, San Raffaele Hospital, Milan, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Magnani
authors.affiliation: Istituto Universitario degli Studi Superiori-IUSS, Pavia, Italy; CERMAC, Vita-Salute San Raffaele University, Milan, Italy.
authors.forename: Stefano F
authors.initials: SF
authors.lastname: Cappa
authors.affiliation: Vita-Salute San Raffaele University and Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy; CERMAC, Vita-Salute San Raffaele University, Milan, Italy; Istituto di Bioimmagini e Fisiologia Molecolare C.N.R., Segrate, Italy; Nuclear Medicine Unit, San Raffaele Hospital, Milan, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Perani
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D018888:Aphasia, Primary Progressive / Q000000981:diagnostic imaging* / Q000473:pathology; D056324:Diffusion Tensor Imaging; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012660:Semantics; D013702:Temporal Lobe / Q000000981:diagnostic imaging / Q000473:pathology
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18