Background

The development and validation of clinical outcome measures to detect early cognitive decline associated with Alzheimer's disease (AD) biomarkers is imperative. Semantic intrusions on the Loewenstein Acevedo Scales of Semantic Interference and Learning (LASSI-L) has outperformed widely used cognitive measures as an early correlate of elevated brain amyloid in prodromal AD and has distinguished those with amnestic mild cognitive impairment (aMCI) and high amyloid load from aMCI attributable to other non-AD conditions.

Methods

Since intrusion errors on memory tasks vary widely, we employed a novel method that accounts for the percentage of intrusion errors (PIE) in relation to total responses. Individuals with either high or low amyloid load across the spectrum of aMCI and dementia and amyloid negative cognitively normal older adults (CN) were studied.

Results

Mean PIE on indices sensitive to proactive semantic interference (PSI) and failure to recover from proactive semantic interference (frPSI) could distinguish amyloid positive from amyloid negative aMCI and dementia groups. Number of correct responses alone, while able to differentiate the different diagnostic groups, did not differentiate amyloid positive aMCI from their counterparts without amyloid pathology.

Conclusions

PIE, a novel and sensitive index of early memory dysfunction, demonstrated high levels of sensitivity and specificity in differentiating CN from amyloid positive persons with preclinical AD. Mean levels of PIE are higher for amyloid positive aMCI and dementia participants relative to their amyloid negative counterparts.

中文翻译：

---

一种评估语义入侵错误以区分阿尔茨海默病连续体上淀粉样蛋白阳性和阴性组的新方法

背景

开发和验证临床结果措施以检测与阿尔茨海默病 (AD) 生物标志物相关的早期认知衰退势在必行。Loewenstein Acevedo 语义干扰和学习量表 (LASSI-L) 的语义入侵作为前驱 AD 中脑淀粉样蛋白升高的早期相关指标优于广泛使用的认知测量，并且区分了那些患有遗忘性轻度认知障碍 (aMCI) 和高淀粉样蛋白负荷的患者来自可归因于其他非 AD 条件的 aMCI。

方法

由于记忆任务的入侵错误差异很大，我们采用了一种新方法来计算入侵错误 (PIE) 相对于总响应的百分比。研究了在 aMCI 和痴呆症以及淀粉样蛋白阴性认知正常老年人 (CN) 范围内具有高或低淀粉样蛋白负荷的个体。

结果

对主动语义干扰 (PSI) 敏感的指数和无法从主动语义干扰 (frPSI) 中恢复的平均 PIE 可以区分淀粉样蛋白阳性和淀粉样蛋白阴性 aMCI 和痴呆组。仅凭正确反应的数量，虽然能够区分不同的诊断组，但不能将淀粉样蛋白阳性 aMCI 与没有淀粉样蛋白病理学的对应物区分开来。

结论

PIE 是早期记忆功能障碍的一种新型敏感指标，在区分 CN 和淀粉样蛋白阳性临床前 AD 患者方面表现出高水平的敏感性和特异性。相对于淀粉样蛋白阴性的参与者，淀粉样蛋白阳性 aMCI 和痴呆参与者的 PIE 平均水平更高。