title: Parahippocampal volume deficits in subjects with aging-associated cognitive decline.
abstract: OBJECTIVE
  Neuropathological evidence suggests that the earliest changes in Alzheimer's disease selectively affect the parahippocampal regions of the brain. This study was conducted to determine if otherwise healthy elderly subjects with mild cognitive impairment had structural volume deficits affecting the parahippocampal gyrus.
  
  
  METHODS
  Magnetic resonance imaging (MRI) was used to compare global and regional brain volumes in 21 subjects with mild cognitive deficits defined according to the criteria for aging-associated cognitive decline, 22 cognitively intact comparison subjects, and 12 patients with Alzheimer's disease.
  
  
  RESULTS
  Compared with the cognitively intact subjects, the subjects with aging-associated cognitive decline had a significantly smaller mean volume of the right parahippocampal gyrus. The subjects with aging-associated cognitive decline had a mean parahippocampal volume that was intermediate between that of the Alzheimer's disease patients and that of the cognitively intact subjects.
  
  
  CONCLUSIONS
  Parahippocampal atrophy underlies the observed cognitive deficits in aging-associated cognitive decline. These findings support the hypothesis that aging-associated cognitive decline represents a preclinical stage of Alzheimer's disease.
authors.affiliation: University of Heidelberg, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Pantel
authors.forename: Benita
authors.initials: B
authors.lastname: Kratz
authors.forename: Marco
authors.initials: M
authors.lastname: Essig
authors.forename: Johannes
authors.initials: J
authors.lastname: Schröder
mesh_terms: D000367:Age Factors; D000368:Aged; D000375:Aging / Q000473:pathology* / Q000502:physiology; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000473:pathology; D001284:Atrophy / Q000473:pathology; D001921:Brain / Q000473:pathology / Q000502:physiology; D003072:Cognition Disorders / Q000175:diagnosis* / Q000473:pathology; D007839:Functional Laterality / Q000502:physiology; D015577:Geriatric Assessment; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D020534:Parahippocampal Gyrus / Q000033:anatomy & histology / Q000473:pathology*