title: Isolated numerical skills in posterior cortical atrophy--an fMRI study.
abstract: Posterior cortical atrophy (PCA) is characterized by bilateral parieto-occipito-temporal atrophy and hypometabolism. Neuropsychological impairments include complex visual disturbances, alexia, agraphia, finger agnosia, right-left disorientation and dyscalculia. A recent case study reported severe numerical deficits with some selectively preserved numerical skills in a patient affected by PCA [Delazer, M., Karner, E., Zamarian, L., Donnemiller, E., & Benke, T. (2006). Number processing in posterior cortical atrophy--a neuropsycholgical case study. Neuropsychologia]. In a functional magnetic resonance imaging (fMRI) study brain activation patterns related to these selectively preserved numerical skills were analyzed. Recitation of multiplication tables and counting forward were contrasted to word recitation in a block design. Contrasts between experimental conditions and control condition yielded significant activation of inferior and medial temporal structures. Since numerical processing is generally associated with parietal activation, it was hypothesized that preserved brain structures would compensate for the functional deficits.
authors.affiliation: Clinical Department of Neurology, Innsbruck Medical University, Innsbruck, Austria. margarete.delazer@uibk.ac.at
authors.forename: Margarete
authors.initials: M
authors.lastname: Delazer
authors.forename: Thomas
authors.initials: T
authors.lastname: Benke
authors.forename: Thomas
authors.initials: T
authors.lastname: Trieb
authors.forename: Michael
authors.initials: M
authors.lastname: Schocke
authors.forename: Anja
authors.initials: A
authors.lastname: Ischebeck
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods; D001284:Atrophy; D001931:Brain Mapping; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008433:Mathematics; D008875:Middle Aged; D009778:Occipital Lobe / Q000098:blood supply / Q000473:pathology / Q000503:physiopathology; D010100:Oxygen / Q000097:blood; D010296:Parietal Lobe / Q000098:blood supply / Q000473:pathology / Q000503:physiopathology
chemical_list: D010100:Oxygen