Gunning-Dixon Faith M, Brickman Adam M, Cheng Janice C, Alexopoulos George S
Institute of Geriatric Psychiatry, Department of Psychiatry, Weill Cornell Medical College, USA.
Int J Geriatr Psychiatry. 2009 Feb;24(2):109-17. doi: 10.1002/gps.2087.
Cerebral aging is a complex and heterogeneous process that is associated with a high degree of inter-individual variability. Structural magnetic resonance imaging (MRI) can be used to identify and quantify non-disease-related aging of the cerebral white matter.
The present article reviews the findings from several MRI techniques, including morphometric approaches, study of white matter hyperintensities, diffusion tensor imaging, and magnetization transfer imaging, that have been used to examine aging of the cerebral white matter. Furthermore, the relationship of MRI indices of white matter integrity to age-related cognitive declines is reported.
A general pattern of age-related preservation and decline emerges indicating that the prefrontal white matter is most susceptible to the influence of age. Studies that combine MRI with cognitive measures suggest that such age-related reductions in white matter integrity may produce a disconnection state that underlies some of the age-related performance declines in age-sensitive cognitive domains.
White matter aging may contribute to a disconnection state that is associated with declines in episodic memory, executive functions, and information processing speed.
脑老化是一个复杂且异质性的过程，个体间差异很大。结构磁共振成像（MRI）可用于识别和量化与疾病无关的脑白质老化。
本文综述了几种MRI技术的研究结果，包括形态测量方法、白质高信号研究、扩散张量成像和磁化传递成像，这些技术已被用于研究脑白质老化。此外，还报告了白质完整性的MRI指标与年龄相关认知衰退的关系。
出现了与年龄相关的保留和衰退的一般模式，表明前额叶白质最易受年龄影响。将MRI与认知测量相结合的研究表明，白质完整性的这种与年龄相关的降低可能会产生一种脱节状态，这是年龄敏感认知领域中一些与年龄相关的表现下降的基础。
白质老化可能导致一种脱节状态，与情景记忆、执行功能和信息处理速度的下降有关。
