Department of Neurology, Faculty Division, Akershus University Hospital, University of Oslo, Lørenskog, Norway.
J Alzheimers Dis. 2013;33(3):723-36. doi: 10.3233/JAD-2012-121603.
Neuropathological correlates of Alzheimer's disease (AD) emerge years before dementia. Biomarkers preceding cognitive decline and reflecting the causative processes can potentially aid early intervention and diagnosis. Diffusion tensor imaging (DTI) indirectly reflects tissue microstructure. To answer whether DTI is an early biomarker for AD and to explore the relationship between DTI and the established biomarkers of medial temporal lobe atrophy and cerebrospinal fluid (CSF) Aβ(42), T-tau, and P-tau, we longitudinally studied normal controls and patients with subjective (SCI) or mild (MCI) cognitive impairment. 21 controls and 64 SCI or MCI cases recruited from a university-hospital based memory clinic were re-examined after two to three years. FreeSurfer was used for longitudinal processing of morphometric data, and DTI derived fractional anisotropy, radial diffusivity, and mean diffusivity were analyzed in Tract-Based Spatial Statistics. Using regression models, we explored and compared the predictive powers of DTI and CSF biomarkers in regard to cognitive change and atrophy of the medial temporal lobe. Both DTI and CSF biomarkers significantly predicted cognitive decline and atrophy in the medial temporal lobe. In this population, however, DTI was a better predictor of dementia and AD-specific medial temporal lobe atrophy than the CSF biomarkers. The case for DTI as an early biomarker for AD is strengthened, but further studies are needed to confirm these results.
阿尔茨海默病（AD）的神经病理学表现早在痴呆症出现多年前就已出现。能够反映致病过程并预示认知能力下降的生物标志物，可能有助于早期干预和诊断。弥散张量成像（DTI）间接反映组织的微观结构。为了回答 DTI 是否为 AD 的早期生物标志物，并探讨 DTI 与内侧颞叶萎缩和脑脊液（CSF）中 Aβ（42）、Tau 蛋白和 P-Tau 等已确立的生物标志物之间的关系，我们对正常对照者和有主观认知障碍（SCI）或轻度认知障碍（MCI）的患者进行了纵向研究。我们从一所大学医院的记忆诊所招募了 21 名正常对照者和 64 名 SCI 或 MCI 患者，对他们进行了为期 2 到 3 年的随访。使用 FreeSurfer 对形态计量数据进行纵向处理，并在基于束的空间统计中分析 DTI 得出的各向异性分数、放射状弥散度和平均弥散度。我们使用回归模型，探索和比较了 DTI 和 CSF 生物标志物在认知变化和内侧颞叶萎缩方面的预测能力。DTI 和 CSF 生物标志物均显著预测了认知能力下降和内侧颞叶萎缩。然而，在该人群中，与 CSF 生物标志物相比，DTI 是痴呆症和 AD 特异性内侧颞叶萎缩的更好预测指标。DTI 作为 AD 早期生物标志物的说法得到了加强，但需要进一步的研究来证实这些结果。
