Department of Psychology, University of Utah, Salt Lake City, UT, USA.
Advanced Neurobehavioral Health of Southern California, San Diego, CA, USA.
J Alzheimers Dis. 2023;95(2):509-521. doi: 10.3233/JAD-230160.
Cognitive change in mild cognitive impairment (MCI), a likely prodrome to Alzheimer's disease, can be tracked with repeated neuropsychological assessments, but there has been little work quantifying these changes over time. Cognitive change can be statistically examined using standardized regression-based (SRB) formulas, which yield a z-score indicating amount of change compared to a normative group.
To use SRB z-scores to quantify cognitive change in a sample of patients classified as MCI at baseline, and to compare cognitive change in those who remained MCI on follow-up (MCI-Stable) and those who progressed to dementia (MCI-Decline).
Using 283 MCI patients from a cognitive disorders clinic who were re-assessed after approximately one- and one-half years, SRB z-scores were calculated for each test in a comprehensive neuropsychological battery for each participant.
There was a significant decline between timepoints across all cognitive tests, with the greatest amount of decline on tests of learning and memory. Group differences were seen on nearly all cognitive tests, with the MCI-Decline group showing more decline (i.e., significantly larger and negative z-scores) than the MCI-Stable participants. Notable cognitive decline was also observed in the MCI-Stable group, with z-scores ranging from -0.01 - -2.24 compared to normative data.
This study highlights the amount of cognitive decline that occurs in MCI, including for those who remain "stable" and those who progress to dementia. It also demonstrates the value of the SRB method in more clearly quantifying cognitive decline, which may help identify individuals most vulnerable to MCI progression.
轻度认知障碍（MCI）是阿尔茨海默病的可能前驱期，其认知变化可以通过重复神经心理学评估来跟踪，但对于随时间推移的这些变化进行量化的研究较少。认知变化可以使用基于标准化回归的（SRB）公式进行统计学检查，该公式产生一个 z 分数，用于指示与正常组相比的变化量。
使用 SRB z 分数来量化基线时被分类为 MCI 的患者样本中的认知变化，并比较在随访中仍为 MCI（MCI-稳定）和进展为痴呆（MCI-下降）的患者的认知变化。
使用认知障碍诊所的 283 名 MCI 患者，他们在大约一年半后重新进行评估，为每位参与者的综合神经心理学测试套件中的每个测试计算 SRB z 分数。
所有认知测试在两个时间点之间都有显著下降，学习和记忆测试的下降幅度最大。在几乎所有认知测试上都观察到组间差异，MCI-下降组的下降幅度（即，显著更大和负的 z 分数）大于 MCI-稳定组。在 MCI-稳定组中也观察到明显的认知下降，z 分数范围从-0.01 到-2.24，与正常数据相比。
本研究强调了 MCI 中发生的认知下降量，包括那些仍保持“稳定”和进展为痴呆的患者。它还证明了 SRB 方法在更清晰地量化认知下降方面的价值，这可能有助于识别最易受 MCI 进展影响的个体。
