Laboratory of Clinical and Behavioral Neurology, IRCCS Santa Lucia Foundation, Rome, Italy.
Department of Systems Medicine, Tor Vergata University, Rome, Italy.
J Geriatr Psychiatry Neurol. 2021 Nov;34(6):582-593. doi: 10.1177/0891988720944244. Epub 2020 Jul 31.
The aim of the current study was to test the accuracy of practice effects, that is, improvement in test performance due to repeated neuropsychological evaluations, in identifying patients with amnestic mild cognitive impairment (a-MCI) at greater risk of conversion to Alzheimer disease (AD). For this purpose, we conducted a longitudinal study of 54 patients diagnosed with a-MCI at the first assessment and followed-up for 4 years. During this time, 18 patients converted to AD. Baseline and 6- to 12-month follow-up performances on a large set of neuropsychological tests were analyzed to determine their diagnostic ability to predict later conversion to dementia. Results demonstrate that a lack of practice effects on episodic memory tests is an accurate prognostic indicator of late conversion to AD in a-MCI patients. In fact, even though the performance of both groups was substantially comparable at the baseline evaluation, stable a-MCI patients greatly improved their memory performance at retest after 6 to 12 months; instead, scores of converter a-MCI remained stable or decreased passing from baseline to follow-up. Standardized z-change scores on memory tasks, which were computed as a reliable measure of performance change, classified group membership with very good overall accuracy, which was higher than the classification of converter and stable a-MCIs provided by baseline or follow-up scores. We hypothesize that the lack of practice effects on memory tasks mirrors the early involvement of medial temporal lobe areas in converter a-MCI that are fundamental for the consolidation of new memory traces.
本研究旨在测试练习效应的准确性，即由于重复进行神经心理学评估而导致测试表现的提高，以识别更有可能发展为阿尔茨海默病（AD）的遗忘型轻度认知障碍（a-MCI）患者。为此，我们对 54 名在首次评估中被诊断为 a-MCI 的患者进行了一项纵向研究，并随访了 4 年。在此期间，有 18 名患者转化为 AD。分析了基线和 6 至 12 个月随访时大量神经心理学测试的表现，以确定它们对预测以后发生痴呆的诊断能力。结果表明，在情景记忆测试中缺乏练习效应是 a-MCI 患者晚期转化为 AD 的准确预后指标。事实上，尽管两组在基线评估时的表现非常相似，但稳定的 a-MCI 患者在 6 至 12 个月后的重新测试中大大提高了他们的记忆表现；相反，转化型 a-MCI 的分数在从基线到随访时保持稳定或下降。记忆任务的标准化 z 变化分数作为可靠的表现变化衡量标准，以非常高的整体准确性对组内成员进行分类，其分类准确性高于基于基线或随访分数的转化型和稳定型 a-MCI 的分类准确性。我们假设记忆任务中缺乏练习效应反映了内侧颞叶区域在转化型 a-MCI 中的早期参与，这对新记忆痕迹的巩固至关重要。
