title: Hippocampal atrophy in the healthy is initially linear and independent of age.
abstract: Patients with minimal cognitive impairment (MCI) or Alzheimer's disease (AD) have smaller hippocampal volumes (HV) and increased rates of HV loss (rHVL). A 6-year study was conducted to assess rHVL in healthy aging subjects (HC) in which four MRI scans, each 2 years apart, were obtained on 26 HC with a mean age of 58.8 years when entering the study. rHVLs were linear and significantly differed among subjects, even those sharing an identical apoliporotein E genotype, ranging from .027 to .191 cc/year (S.D. = .022 cc/year), and were not affected by age or sex. rHVL, but not HV, at time of subject entry, was found to predict performance on the delayed recall measure of the Selective Reminder Task obtained 6 years after subject entry into study. Although the molecular events underlying rHVL are unclear, the significance of rHVL in subjects in their sixth and seventh decades of life for predicting age-related cognitive trajectories and whether changes in rHVLs foreshadow the development of MCI are the subject of ongoing study.
authors.affiliation: Geriatric Psychiatry Branch, National Institute of Mental Health, National Institutes of Health, Clinical Research Center 2-5362, MSC 1274, 10 Center Drive, Bethesda MD 20892-1274, USA. rcn1946@mac.com
authors.forename: Robert M
authors.initials: RM
authors.lastname: Cohen
authors.forename: Joanna
authors.initials: J
authors.lastname: Szczepanik
authors.forename: Michael
authors.initials: M
authors.lastname: McManus
authors.forename: Nadeem
authors.initials: N
authors.lastname: Mirza
authors.forename: Karen
authors.initials: K
authors.lastname: Putnam
authors.forename: Jim
authors.initials: J
authors.lastname: Levy
authors.forename: Trey
authors.initials: T
authors.lastname: Sunderland
mesh_terms: D000367:Age Factors; D000368:Aged; D000375:Aging / Q000473:pathology*; D001284:Atrophy / Q000473:pathology; D003072:Cognition Disorders / Q000473:pathology* / Q000503:physiopathology*; D003198:Computer Simulation; D005260:Female; D006624:Hippocampus / Q000473:pathology* / Q000503:physiopathology*; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D012016:Reference Values