The relationship between simple numerical function and gray matter volume in normal brain aging

Abstract

Objective: To explore the relationship between simple numerical function and gray matter volume (GMV) in normal brain aging using the voxel-based morphometry(VBM) approach. Methods: A total of 123 individuals from 18 to 70 years old (63 males,60 females,the average age was (43±14) years, were recruited from right-handed healthy Han Chinese volunteers at the Department of MRI at the First Affiliated Hospital of Zhengzhou University between October 2016 and June 2017. All subjects underwent magnetic resonance sagital three-dimensional imaging scanning, and statistical parameter graph (SPM) 8 software was used for voxel-based morphological analysis to compare the differences in gray matter volume between different age groups.Gray matter volume difference brain regions between different age groups were extracted as regions of interest, and correlation analysis was carried out on the score of simple numerical calculation to find the responsible atrophy brain regions related to the decline of simple digital computing ability. Results: The brain regions with different gray matter volume in different age groups mainly included bilateral frontal gyrus, bilateral anterior cingulate gyrus, bilateral middle cingulate gyrus, bilateral olfactory cortex, bilateral caudate nucleus and bilateral insula. Among them the GMV of bilateral superior frontal gyrus and anterior cingulate gyrus showed the strongest correlation with the simple numerical function. Before removing the effect of age, the correlation between the GMV of the bilateral superior frontal gyrus and medial cingulate gyrus and the corrected count of correct was significant (r=0.403,P=0.000), the correlation between GMV and the percent of correct was also significant (r=0.229,P=0.037).After removing age as a covariate, bilateral superior frontal gyrus and central cingulate gyrus were still positively correlated with the correct number after correction of simple numerical calculation function (r=0.225,P=0.014) and the correct percentage (r=0.245, P=0.007). Conclusion: There is extensive gray matter volume atrophy during the normal brain aging process. The decrease of simple numerical function in normal brain aging may be related to the decrease of frontal and anterior cingulate gray matter volume.