Age-Related Regional Cerebral Glucose Metabolism Reduction in Healthy Normal Volunteers

Objective:The main objective of this study was to evaluate the age-related changes of the regional cerebral glucose metabolism in normal healthy volunteers utilizing Statistical Parametric Mapping(SPM)software. Methods:1 8F-FDG PET images of the entire brain were obtained in 266 healthy normal volunteers(173 men,93 women),age range from 21 to 87 yr.They were divided into 7groups according to their age(every 10 year for a group).Each group was compared with the next 10year group and each group(age>30yr)was compared with the basal states(the group of 20~29 yr)using SPM 2(two sample t-test,P<0.001).The hypo-metabolic areas were shown and the voxel value of each active area can be calculated.Results:The cerebral glucose metabolism of the entire brain was decreased with aging and it decreased the most during the seventies.②The regional cerebral glucose metabolism of different anatomic regions decreased in different stages.There was no glucose metabolism decrease in any anatomic region before 40.At forties only the left frontal lobes showed a glucose metabolism reduction.At fifties regional cerebral glucose metabolism reduction were seen in right frontal lobe,right parietal lobe and anterior cingulate gyrus.At sixties regional cerebral glucose metabolism reduction were seen in bilateral parietal lobes and caudate nucleus.③The regional cerebral glucose metabolism of different anatomic regions decreased at different levels.The greatest reduction in regional cerebral glucose metabolism occurred within the bilateral frontal lobes,followed by anterior cingulate gyrus,parietal lobes,caudate nucleus,temple lobes and cerebellum.④Bilateral occipital lobe,posterior cingulate gyrus,dorsal caudate putamen and thalamus remained metabolically unchanged with advancing age.Conclusion:We observed an age-related reduction in regional cerebral glucose metabolism mainly in the bilateral frontal gyrus,bilateral cingulate gyrus,bilateral parietal lobes and bilateral caudate nucleus.The reduction of the regional cerebral glucose metabolism in these lobes began at in different stages and the first reduction occurred in the left frontal lobe.The metabolism of different anatomic regions decreased at different levels and the greatest reduction occurred within the bilateral frontal lobes and bilateral anterior cingulate gyrus.