Changes in Cerebral Glucose Metabolism with Normal Aging

The pattern of changes in cerebral glucose metabolism occurring with normal aging has been unclear. Advances in imaging technology, such as improved resolution and anatomical referencing, allow for more precise regional measurement than previously possible. This study explored cerebral glucose metabolism in 17 normal controls ranging in age from 20 to 74 years. High resolution PET scanning, with MRI-based regions of interest correcting for partial volume and atrophy effects, revealed a linear association between advancing age and declining cerebral glucose metabolism. The decline averaged 8% per decade for the whole brain. Changes were most pronounced in limbic structures, and could be implicated in age-associated memory loss.