健康成人大脑灰质体积年龄相关性变化的研究

The age-related changes of cerebral gray matter volume in healthy adults

目的探讨正常脑老化过程灰质体积年龄相关性的改变规律。方法应用MR采集124例健康志愿者全脑T1WI图像,利用VBM技术获得全脑灰质体积。采用双因素方差分析不同性别及年龄组间灰质体积的差异性。结果每2个年龄组间均存在显著的年龄主效应(P<0.05,FDR校正)。其中中年组与青年组比较,存在明显萎缩的脑区位于两侧额上回、两侧额下回三角部、右侧额下回眶部、双侧丘脑、双侧颞中回、右侧额上回眶面、右侧颞中极、右侧岛叶、右侧尾状核及右侧顶叶。老年组与中年组比较存在明显萎缩的脑区位于右侧颞中极、杏仁核、扣带回后部、两侧枕叶舌回、两侧海马/海马旁回及两侧颞下极。老年组与青年组比较,除枕叶外,老年组全脑灰质体积存在广泛下降。当不采用多重对比校正时,观察到青年组与中年组之间部分脑区,如右侧颞中回、右侧颞上回、左侧角回、右侧枕叶中部、左侧扣带回中部、右额下回三角部,存在年龄×性别交互效应(P<0.01,未校正)。结论在正常老化过程中,全脑灰质体积与年龄呈现为负相关性改变,不同脑区存在不同的萎缩模式,一般遵循"先进后出"的规律,其中额叶最易受年龄的影响;并且在部分脑区中,女性灰质萎缩进程较男性缓慢。

Objective To explore the age-related changes of cerebral grey matter volume in healthy adults. Methods The 3D brain MRI was used to get T1 WI image in 124 healthy volunteers. The VBM（ Voxel-based morphometry） technique was applied to detect cerebral gray matter volume. The differences of cerebral grey matter volume in different sex groups and age groups were compared by Two-way analysis of variance. Results There were significant main effect of age between every two groups（ P〈0. 05,FDR correction）. As compared with youth group,the middle age group showed that obvious brain atrophy regions located in the frontal gyrus,bilateral triangle inferior frontal gyrus,right inferior frontal gyrus,bilateral thalamus in return,middle temporal gyrus,right superior frontal gyrus,middle temporal gyrus pole,right insula,right caudate nucleus and right parietal lobe. As compared with middle age group,the older age group showed that obvious brain atrophy regions located in right middle temporal gyrus pole,amygdale,posterior cingutate,lingual gyrus,hippocampus / parahippocampus and inferior temporal pole. As compared with youth group,the older age group showed that the cerebral gray matter volume was extensively decreased in whole brain except for occipital lobe. When multiple alignment correction was not used,interaction effect could be observed between youth group and middle age group in right middle temporal gyrus,right superior temporal gyrus,left angular gyrus,right occipital lobe,central left cingulate gyrus,right inferior frontal gyrus in central triangle（ P〈0. 01,no correction）.Conclusion During normal aging process,whole brain gray matter volume is negatively correlated to age. However different encephalic regions exist different shrink modes. Generally the regions follow the regulation- ＂ first-in last-out＂ in which the frontal lobe is the most easily affected by age. The grey matter atrophy process in females is slower,as compared with that in males.