Association of age with regional cerebral oxygen utilization: a positron emission tomography study.

Positron emission tomography scans were performed on 14 normal subjects over the age of 50. Cerebral metabolic rate for oxygen (CMRO2) was assessed in a number of cortical and subcortical regions. There was a trend for a decrease in CMRO2 with age but this was significant only in the parietal lobe. There was a suggestion that the age/CMRO2 correlation became less strong with advancing age. CMRO2 in the occipital lobe, subcortical regions and cerebellum was not related to age. The relationship between CMRO2 and age is discussed.