title: Differences in cortical thickness in healthy controls, subjects with mild cognitive impairment, and Alzheimer's disease patients: a longitudinal study.
abstract: In this study, we analyzed differences in cortical thickness (CTH) between healthy controls (HC), subjects with stable mild cognitive impairment (S-MCI), progressive MCI (P-MCI), and Alzheimer's disease (AD), and assessed correlations between CHT and clinical disease severity, education, and apolipoprotein E4 (APOE) genotype. Automated CTH analysis was applied to baseline high-resolution structural MR images of 145 subjects with a maximum followup time of 7.4 years pooled from population-based study databases held in the University of Kuopio. Statistical differences in CTH between study groups and significant correlations between CTH and clinical and demographic factors were assessed and displayed on a cortical surface model. Compared to HC group (n = 26), the AD (n = 21) group displayed significantly reduced CTH in several areas of frontal and temporal cortices of the right hemisphere. Higher education and lower MMSE scores were correlated with reduced CTH in the AD group, whereas no significant correlation was found between CDR-SB scores or APOE genotype and CTH. The P-MCI group demonstrated significantly reduced CTH compared to S-MCI in frontal, temporal and parietal cortices even after statistically adjusting for all confounding variables. Ultimately, analysis of CTH can be used to detect cortical thinning in subjects with progressive MCI several years before conversion and clinical diagnosis of AD dementia, irrespective of their cognitive performance, education level, or APOE genotype.
authors.affiliation: Department of Neurology, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Valtteri
authors.initials: V
authors.lastname: Julkunen
authors.forename: Eini
authors.initials: E
authors.lastname: Niskanen
authors.forename: Juha
authors.initials: J
authors.lastname: Koikkalainen
authors.forename: Sanna-Kaisa
authors.initials: SK
authors.lastname: Herukka
authors.forename: Maija
authors.initials: M
authors.lastname: Pihlajamäki
authors.forename: Merja
authors.initials: M
authors.lastname: Hallikainen
authors.forename: Miia
authors.initials: M
authors.lastname: Kivipelto
authors.forename: Sebastian
authors.initials: S
authors.lastname: Muehlboeck
authors.forename: Alan C
authors.initials: AC
authors.lastname: Evans
authors.forename: Ritva
authors.initials: R
authors.lastname: Vanninen
authors.lastname: Hilkka Soininen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis / Q000473:pathology*; D002540:Cerebral Cortex / Q000473:pathology*; D003072:Cognition Disorders / Q000175:diagnosis / Q000473:pathology*; D060825:Cognitive Dysfunction / Q000175:diagnosis / Q000473:pathology*; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged