Dementia Research Centre, Institute of Neurology, University College London, Queen Square, London, WC1N 3BG, UK.
Neurobiol Aging. 2011 Aug;32(8):1466-76. doi: 10.1016/j.neurobiolaging.2009.08.017. Epub 2009 Sep 25.
A significant minority of Alzheimer's disease patients present with posterior cortical atrophy (PCA). PCA is characterized by visuospatial and visuoperceptual deficits, and relatively preserved memory, whereas patients with typical Alzheimer's disease (tAD) mostly present with early episodic memory deficits. We used two unbiased image analysis techniques to assess atrophy patterns in 48 PCA, 30 tAD, and 50 healthy controls. FreeSurfer was used to measure cortical thickness, and volumetric grey matter differences were assessed using voxel-based morphometry (VBM). Both PCA and tAD showed widespread reductions compared with controls using both techniques. Direct comparison of PCA and tAD revealed thinner cortex predominantly in the right superior parietal lobe in the PCA group compared with tAD, whereas the tAD group showed thinning in the left entorhinal cortex compared with PCA. Similar results were obtained in the VBM analysis. These distinct patterns of atrophy may have diagnostic utility. In a clinical context, a relatively spared medial temporal lobe in the presence of posterior parietal atrophy may imply PCA, and should not discount AD.
少数阿尔茨海默病患者表现出后皮质萎缩（PCA）。PCA 的特征是存在视觉空间和视觉感知缺陷，以及相对保留的记忆，而典型的阿尔茨海默病（tAD）患者大多表现为早期情景记忆缺陷。我们使用两种无偏图像分析技术评估了 48 例 PCA、30 例 tAD 和 50 例健康对照组的萎缩模式。使用 FreeSurfer 测量皮质厚度，使用基于体素的形态测量学（VBM）评估灰质体积差异。使用这两种技术，PCA 和 tAD 与对照组相比均显示出广泛的减少。PCA 和 tAD 的直接比较显示，与 tAD 相比，PCA 组右侧顶叶上回的皮质更薄，而与 PCA 相比，tAD 组的左侧内嗅皮层变薄。VBM 分析也得到了类似的结果。这些不同的萎缩模式可能具有诊断效用。在临床环境中，在后顶叶萎缩的情况下，内侧颞叶相对保留可能意味着 PCA，不应排除 AD。
