Loewenstein David A, Acevedo Amarilis, Ownby Raymond, Agron Joscelyn, Barker Warren W, Isaacson Richard, Strauman Silvia, Duara Ranjan
Wien Center for Alzheimer's Disease and Memory Disorders, Mount Sinai Medical Center, Miami Beach, FL 33140, USA.
Am J Geriatr Psychiatry. 2006 Nov;14(11):911-9. doi: 10.1097/01.JGP.0000229651.62137.e2.
Although mild cognitive impairment (MCI) is characterized by performance on memory and other measures below expected normative values, neither a scientific rationale nor a consensus exists regarding which measures have the most use or the optimal cutoffs to use to establish impairment.
Different memory measures were administered to 80 normal community-dwelling subjects divided into two age groups. This provided conormed data on eight different memory indices by which to compare 23 nondemented clinically diagnosed patients with MCI who met all other criteria for Alzheimer disease (AD).
On immediate memory for passages, delayed visual reproduction, object memory, and a measure sensitive to semantic interference, 70%-78% of patients with MCI were identified as impaired at 1.5 standard deviations or greater below expected levels. Conditional logistical regression for age-matched samples indicated that consideration of raw scores for these neuropsychologic tests in combination did not significantly change the odds of MCI diagnosis. When impairment relative to the total normal elderly sample was calculated based on one or more impairments at a 1.5 or greater cutoff, specificity fell below acceptable levels when more than three memory measures were considered.
An array of widely used neuropsychologic measures demonstrated utility in distinguishing patients with MCI-AD from cognitively normal community-dwelling elders. The appropriateness of more or less stringent cutoffs was highly influenced by the number of measures considered. These findings have important implications regarding the choice of cut points for impairment used for the diagnosis of MCI in both research and clinical settings.
尽管轻度认知障碍（MCI）的特征是在记忆和其他测量指标上的表现低于预期的正常标准值，但对于哪些测量指标最有用以及用于确定损伤的最佳临界值，既没有科学依据，也没有达成共识。
对80名居住在社区的正常受试者进行不同的记忆测量，这些受试者分为两个年龄组。这提供了关于八个不同记忆指标的共同常模数据，通过这些数据可以比较23名临床诊断为MCI且符合阿尔茨海默病（AD）所有其他标准的非痴呆患者。
在段落即时记忆、延迟视觉再现、物体记忆以及对语义干扰敏感的一项测量指标上，70%-78%的MCI患者在低于预期水平1.5个标准差或更大时被确定为受损。年龄匹配样本的条件逻辑回归表明，综合考虑这些神经心理学测试的原始分数并没有显著改变MCI诊断的几率。当根据在1.5或更大临界值处的一项或多项损伤计算相对于全部正常老年样本的损伤情况时，当考虑超过三项记忆测量指标时，特异性低于可接受水平。
一系列广泛使用的神经心理学测量指标在区分MCI-AD患者与认知正常的社区居住老年人方面显示出效用。临界值的宽松或严格程度的适宜性受到所考虑测量指标数量的高度影响。这些发现对于研究和临床环境中用于MCI诊断的损伤切点选择具有重要意义。
