Dipartimento di Neuroscienze, Università di Modena e Reggio Emilia, Modena, Italy.
Neurobiol Aging. 2012 Apr;33(4):825.e25-36. doi: 10.1016/j.neurobiolaging.2011.05.018. Epub 2011 Jul 22.
Structural brain changes have been described in both mild cognitive impairment (MCI) and Alzheimer's disease (AD). However, less is known about whether structural changes are detectable earlier, in the asymptomatic phase. Using voxel-based morphometry (VBM) and shape analyses of magnetic resonance imaging (MRI) data, we investigated structural brain differences between groups of healthy subjects, stratified by subsequent diagnoses of MCI or AD during a 10-year follow-up. Images taken at baseline, at least 4 years before any cognitive symptoms, showed that subjects with future cognitive impairment (preclinical AD and MCI) had reduced brain volume in medial temporal lobes, posterior cingulate/precuneus, and orbitofrontal cortex, compared with matched subjects who remained cognitively healthy for 10 years (HC). For only those subjects later diagnosed as AD, significantly greater atrophy at baseline was detected in the right medial temporal lobe, which was also confirmed by shape analysis of the right hippocampus in these subjects. Our results demonstrate that structural brain changes occur years before clinical cognitive decline in AD and are localized to regions affected by AD neuropathology.
结构脑变化在轻度认知障碍 (MCI) 和阿尔茨海默病 (AD) 中均有描述。然而，对于在无症状阶段是否可以更早地检测到结构变化，人们知之甚少。我们使用基于体素的形态计量学 (VBM) 和磁共振成像 (MRI) 数据的形状分析，研究了在 10 年随访中，根据随后的 MCI 或 AD 诊断对健康受试者进行分组的结构脑差异。在基线时拍摄的图像（至少在出现任何认知症状前 4 年）显示，与认知健康持续 10 年的匹配受试者相比，未来有认知障碍（临床前 AD 和 MCI）的受试者在海马体等内侧颞叶、后扣带回/楔前叶和眶额皮层的脑体积减少。对于仅以后被诊断为 AD 的那些受试者，在右侧内侧颞叶更早地检测到明显的萎缩，这在这些受试者的右侧海马体的形状分析中也得到了证实。我们的结果表明，在 AD 出现临床认知下降之前，结构脑变化会提前数年发生，并且定位于受 AD 神经病理学影响的区域。
