title: Greater cortical thinning in normal older adults predicts later cognitive impairment.
abstract: Cross-sectional studies have shown regional differences in cortical thickness between healthy older adults and patients with Alzheimer's disease (AD) or mild cognitive impairment (MCI). We now demonstrate that participants who subsequently develop cognitive impairment leading to a diagnosis of MCI or AD (n = 25) experience greater cortical thinning in specific neuroanatomic regions compared with control participants who remained cognitively normal (n = 96). Based on 8 years of annual magnetic resonance imaging scans beginning an average of 11 years before onset of cognitive impairment, participants who developed cognitive impairment subsequent to the scanning period had greater longitudinal cortical thinning in the temporal poles and left medial temporal lobe compared with controls. No significant regional cortical thickness differences were found at baseline between the 2 study groups indicating that we are capturing a critical time when brain changes occur before behavioral manifestations of impairment are detectable. Our findings suggest that early events of the pathway that leads to cognitive impairment may involve the temporal lobe and that this increased atrophy could be considered an early biomarker of neurodegeneration predictive of cognitive impairment years later.
authors.affiliation: Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA. Electronic address: jenni.pacheco@nih.gov.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Pacheco
authors.affiliation: Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA; Graduate Institute of Brain and Mind Sciences, National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Joshua O
authors.initials: JO
authors.lastname: Goh
authors.affiliation: Russell H. Morgan Department of Radiology and Radiological Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Kraut
authors.affiliation: Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA.
authors.forename: Luigi
authors.initials: L
authors.lastname: Ferrucci
authors.affiliation: Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA.
authors.forename: Susan M
authors.initials: SM
authors.lastname: Resnick
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis / Q000473:pathology; D001284:Atrophy; D003072:Cognition Disorders / Q000175:diagnosis / Q000473:pathology; D060825:Cognitive Dysfunction / Q000175:diagnosis* / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D013702:Temporal Lobe / Q000473:pathology*; D013997:Time Factors
keywords: Alzheimer's disease; Cortical thinning; Early detection; Longitudinal; Mild cognitive impairment