Liddell Belinda J, Paul Robert H, Arns Martijn, Gordon Norman, Kukla Matthew, Rowe Donald, Cooper Nick, Moyle Jonson, Williams Leanne M
The Brain Resource International Database and the Brain Resource Company, NSW 2007, Australia.
J Integr Neurosci. 2007 Mar;6(1):141-74. doi: 10.1142/s0219635207001374.
Increasing age is the strongest risk factor for Alzheimer's disease (AD). Yet, departure from normal age-related decline for established markers of AD including memory, cognitive decline and brain function deficits, has not been quantified.
We examined the cross-sectional estimates of the "rate of decline" in cognitive performance and psychophysiological measures of brain function over age in AD, preclinical (subjective memory complaint-SMC, Mild Cognitive Impairment-MCI) and healthy groups. Correlations between memory performance and indices of brain function were also conducted.
The rate of cognitive decline increased between groups: AD showed advanced decline, and SMC/MCI groups represented intermediate stages of decline relative to normal aging expectations. In AD, advanced EEG alterations (excessive slow-wave/reduced fast-wave EEG, decreased working memory P450 component) were observed over age, which were coupled with memory decline. By contrast, MCI group showed less severe cognitive changes but specific decreases in the working memory N300 component and slow-wave (delta) EEG, associated with decline in memory. DISCUSSION AND INTEGRATIVE SIGNIFICANCE: While the cognitive data suggests a continuum of deterioration associated with increasing symptom severity across groups, integration with brain function measures points to possible distinct compensatory strategies in MCI and AD groups. An integrative approach offers the potential for objective markers of the critical turning point, with age as a potential factor, from mild memory problems to disease.
年龄增长是阿尔茨海默病（AD）最强的风险因素。然而，对于包括记忆、认知衰退和脑功能缺陷在内的AD既定标志物，偏离正常的年龄相关衰退情况尚未得到量化。
我们研究了AD组、临床前组（主观记忆主诉-SMC、轻度认知障碍-MCI）和健康组中认知表现和脑功能心理生理测量指标随年龄的“衰退率”的横断面估计值。还进行了记忆表现与脑功能指标之间的相关性研究。
认知衰退率在各组之间有所增加：AD组显示出更严重的衰退，而SMC/MCI组相对于正常衰老预期代表了衰退的中间阶段。在AD组中，随着年龄增长观察到了晚期脑电图改变（过度慢波/快速波脑电图减少、工作记忆P450成分降低），这与记忆衰退相关。相比之下，MCI组显示出不太严重的认知变化，但工作记忆N300成分和慢波（δ）脑电图有特定降低，与记忆衰退相关。讨论与综合意义：虽然认知数据表明各组中症状严重程度增加与恶化的连续性，但与脑功能测量指标相结合表明MCI组和AD组可能存在不同的代偿策略。综合方法为从轻度记忆问题到疾病的关键转折点提供了客观标志物的潜力，年龄是一个潜在因素。
