Institut Universitaire de Gériatrie de Montréal, Montréal, Canada.
J Alzheimers Dis. 2014;38(2):307-18. doi: 10.3233/JAD-130842.
The objective of this work was to assess the predictive accuracy of targeted neuroimaging and neuropsychological measures for the detection of incipient dementia in individuals with mild cognitive impairment (MCI), and to examine the potential benefit of combining both classes of measures. Baseline MRI measures included hippocampal volume, cortical thickness, and white matter hyperintensities. Neuropsychological assessment focused on different aspects of episodic memory (i.e., familiarity, free recall, and associative memory) and executive control functions (i.e., working memory, switching, and planning). Global and regional cortical thinning was observed in MCI patients who progressed to dementia compared to those who remained stable, whereas no differences were found between groups for baseline hippocampal volume and white matter hyperintensities. The strongest neuroimaging predictors were baseline cortical thickness in the right anterior cingulate and middle frontal gyri. For cognitive predictors, we found that deficits in both free recall and recognition episodic memory tasks were highly suggestive of progression to dementia. Cortical thinning in the right anterior cingulate gyrus, combined to controlled and familiarity-based retrieval deficits, achieved a classification accuracy of 87.5%, a specificity of 90.9%, and a sensitivity of 83.3%. This predictive model including both classes of measures provided more accurate predictions than those based on neuroimaging or cognitive measures alone. Overall, our findings suggest that detecting preclinical Alzheimer's disease is probably best accomplished by combining complementary information from targeted neuroimaging and cognitive classifiers, and highlight the importance of taking into account both structural and functional changes associated with the disease.
本研究旨在评估靶向神经影像学和神经心理学测量在检测轻度认知障碍（MCI）个体早期痴呆中的预测准确性，并探讨联合使用这两类测量方法的潜在益处。基线 MRI 测量包括海马体积、皮质厚度和脑白质高信号。神经心理学评估侧重于情景记忆（即熟悉度、自由回忆和联想记忆）和执行控制功能（即工作记忆、转换和计划）的不同方面。与稳定组相比，进展为痴呆的 MCI 患者出现了全脑和区域性皮质变薄，而基线海马体积和脑白质高信号在两组之间没有差异。最强的神经影像学预测因子是右侧前扣带回和额中回的基线皮质厚度。对于认知预测因子，我们发现自由回忆和识别情景记忆任务中的缺陷高度提示向痴呆进展。右侧前扣带回皮质变薄，加上控制和基于熟悉度的检索缺陷，实现了 87.5%的分类准确性、90.9%的特异性和 83.3%的敏感性。与仅基于神经影像学或认知测量的预测模型相比，包含这两类测量的预测模型提供了更准确的预测。总体而言，我们的研究结果表明，通过结合靶向神经影像学和认知分类器的互补信息，可能更有助于检测临床前阿尔茨海默病，这突显了考虑与疾病相关的结构和功能变化的重要性。
