Hippocampal hypometabolism predicts cognitive decline from normal aging

Neurobiol Aging. 2008 May;29(5):676-92. doi: 10.1016/j.neurobiolaging.2006.12.008. Epub 2007 Jan 11.


Objective: This longitudinal study used FDG-PET imaging to predict and monitor cognitive decline from normal aging.

Methods: Seventy-seven 50-80-year-old normal (NL) elderly received longitudinal clinical examinations over 6-14 years (561 person-years, mean per person 7.2 years). All subjects had a baseline FDG-PET scan and 55 subjects received follow-up PET exams. Glucose metabolic rates (MRglc) in the hippocampus and cortical regions were examined as predictors and correlates of clinical decline.

Results: Eleven NL subjects developed dementia, including six with Alzheimer's disease (AD), and 19 declined to mild cognitive impairment (MCI), on average 8 years after the baseline exam. The baseline hippocampal MRglc predicted decline from NL to AD (81% accuracy), including two post-mortem confirmed cases, from NL to other dementias (77% accuracy), and from NL to MCI (71% accuracy). Greater rates of hippocampal and cortical MRglc reductions were found in the declining as compared to the non-declining NL.

Conclusions: Hippocampal MRglc reductions using FDG-PET during normal aging predict cognitive decline years in advance of the clinical diagnosis. Future studies are needed to increase preclinical specificity in differentiating dementing disorders.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Aged, 80 and over
  • Aging / metabolism*
  • Cognition Disorders / complications
  • Cognition Disorders / diagnostic imaging
  • Cognition Disorders / metabolism*
  • Dementia / diagnostic imaging*
  • Dementia / metabolism
  • Female
  • Fluorodeoxyglucose F18 / pharmacokinetics*
  • Glucose / metabolism*
  • Glucose Metabolism Disorders / complications
  • Glucose Metabolism Disorders / diagnostic imaging
  • Glucose Metabolism Disorders / metabolism*
  • Hippocampus / diagnostic imaging
  • Hippocampus / metabolism*
  • Humans
  • Male
  • Middle Aged
  • Radionuclide Imaging
  • Radiopharmaceuticals / pharmacokinetics
  • Statistics as Topic


  • Radiopharmaceuticals
  • Fluorodeoxyglucose F18
  • Glucose