National Institute of Mental Health and Neurosciences, Hosur Road, Bangalore, India.
Aging Dis. 2012 Dec 20;4(2):65-75. Print 2013 Apr.
Gradual decline in adult stem cells over time at Subventricular zone (SVZ) may contribute to age related changes and neurodegenerative diseases. Study was aimed to evaluate in vivo age-related neuroimaging changes in cortical, subcortical, and SVZ. Sixty four healthy volunteers were recruited from various ongoing studies and subjects were grouped in to pediatric with age less than 18yrs (n=13, females=6) aged 11.8 ± 2.9 yrs, middle aged between 19 to 59 yrs (n=38, female=15) aged 40.4 ± 12.2yrs and elderly above 60yrs (n=13, females=6) aged 65.3 ± 6.0yrs, subgroups. Subjects underwent MRI scanning on a 3T MR scanner and Diffusion Tensor Imaging data with 3d T1TFE data was acquired. DTI was processed using region of interest (ROI) analysis method and the results were observed at p < 0.05 corrected for multiple corrections. Cortical, WM and subcortical GM volumes were extracted using a fully automated method. The cortical volumes (grey, white & whole brain) were least in elderly and highest in pediatric group. Among subgroup analysis following subcortical nuclei significantly differed on; fractional anisotropy (FA): bilateral hippocampus, right pallidum and left amygdale & caudate; Mean diffusivity (MD): bilateral thalamus, right pallidum, left caudate & accumbens; radial diffusivity (RD): bilateral pallidum, left caudate, left thalamus and left accumbens; axial diffusivity (AD): bilateral caudate, bilateral thalamus and left accumbens. The MD, RD and AD values of at SVZ around caudate were also significantly different between subgroups. Study observes patterns of volumetric and DTI changes across normal aging. Alterations in DTI parameters in subcortical and SVZ may indicate changes in neurogenic region in aging process; however longitudinal studies are required for further validation.
随着时间的推移，脑室下区（SVZ）中的成人干细胞逐渐减少，可能导致与年龄相关的变化和神经退行性疾病。本研究旨在评估皮质、皮质下和 SVZ 中与年龄相关的神经影像学变化。从各种正在进行的研究中招募了 64 名健康志愿者，并将受试者分为儿科组（年龄小于 18 岁，n=13，女性=6），年龄为 11.8±2.9 岁；中年组（19 至 59 岁，n=38，女性=15），年龄为 40.4±12.2 岁；老年组（年龄大于 60 岁，n=13，女性=6），年龄为 65.3±6.0 岁。受试者在 3T MR 扫描仪上进行 MRI 扫描，并采集 3d T1TFE 数据的弥散张量成像（DTI）数据。使用感兴趣区（ROI）分析方法处理 DTI，并在进行多次校正后观察到 p<0.05 的结果。使用全自动方法提取皮质、WM 和皮质下 GM 体积。皮质体积（灰质、白质和全脑）在老年组中最小，在儿科组中最大。在亚组分析中，以下皮质下核显著不同：各向异性分数（FA）：双侧海马体、右侧苍白球和左侧杏仁核和尾状核；平均弥散度（MD）：双侧丘脑、右侧苍白球、左侧尾状核和伏隔核；径向弥散度（RD）：双侧苍白球、左侧尾状核、左侧丘脑和左侧伏隔核；轴向弥散度（AD）：双侧尾状核、双侧丘脑和左侧伏隔核。SVZ 周围尾状核的 MD、RD 和 AD 值在亚组之间也有显著差异。本研究观察了正常衰老过程中体积和 DTI 变化的模式。皮质下和 SVZ 的 DTI 参数的改变可能表明神经发生区域在衰老过程中的变化；然而，需要进行纵向研究以进一步验证。
