title: Calculation impairment in neurodegenerative diseases.
abstract: We examined oral calculation in patients with corticobasal degeneration (CBD; N=17), frontotemporal dementia (FTD; N=17), and Alzheimer's disease (AD; N=20), as well as 17 healthy seniors matched for age and education. Our calculation model involves at least three components: numerosity, combinatorial processes, and executive resources such as working memory. We assessed addition, subtraction, multiplication, and division involving small numbers (small, single-digit answers) and large numbers (larger, single- and double-digit answers). We also assessed dot counting for small numbers (2-5) and large numbers (6-9), as well as a measure of working memory. All patient groups differed from healthy seniors in oral calculation. CBD (36% correct) and FTD (65% correct) demonstrated a significant overall impairment in oral calculation relative to AD (76% correct). CBD (66% correct) had more difficulty counting dots overall relative to AD (94% correct) and FTD (86% correct), consistent with our hypothesis that the calculation deficit in CBD is due in large part to a numerosity deficit. FTD had more difficulty relative to AD in their performance of reverse digit span, consistent with our hypothesis that FTD patients' executive resource limitation contributes to their pattern of calculation impairment.
authors.affiliation: Department of Neurology-3 Gates, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia 19104-4283, USA.
authors.forename: Casey
authors.initials: C
authors.lastname: Halpern
authors.forename: Corey
authors.initials: C
authors.lastname: McMillan
authors.forename: Peachie
authors.initials: P
authors.lastname: Moore
authors.forename: Kari
authors.initials: K
authors.lastname: Dennis
authors.forename: Murray
authors.initials: M
authors.lastname: Grossman
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000503:physiopathology; D003704:Dementia / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008433:Mathematics; D008570:Memory, Short-Term; D011939:Mental Recall / Q000502:physiology; D015999:Multivariate Analysis; D019636:Neurodegenerative Diseases / Q000145:classification / Q000503:physiopathology*; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D013132:Spinocerebellar Degenerations / Q000503:physiopathology