Memory Clinic, Department of Neurology, Charles University, 2nd Faculty of Medicine and Motol University Hospital, Prague, Czech Republic.
International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czech Republic.
J Alzheimers Dis. 2020;76(1):121-138. doi: 10.3233/JAD-200093.
The hippocampus, entorhinal cortex, and basal forebrain are among the first brain structures affected by Alzheimer's disease (AD). They play an essential role in spatial pattern separation, a process critical for accurate encoding of similar spatial information.
Our aim was to examine spatial pattern separation and its association with volumetric changes of the hippocampus, entorhinal cortex, and basal forebrain nuclei projecting to the hippocampus (the medial septal nuclei and vertical limb of the diagonal band of Broca - Ch1-2 nuclei) in the biomarker-defined early clinical stages of AD.
A total of 98 older adults were recruited from the Czech Brain Aging Study cohort. The participants with amnestic mild cognitive impairment (aMCI) due to AD (n = 44), mild AD dementia (n = 31), and cognitively normal older adults (CN; n = 23) underwent spatial pattern separation testing, comprehensive cognitive assessment, and MRI brain volumetry.
Spatial pattern separation accuracy was lower in the early clinical stages of AD compared to the CN group (p < 0.001) and decreased with disease severity (CN > aMCI due to AD > AD dementia). Controlling for general memory and cognitive performance, demographic characteristics and psychological factors did not change the results. Hippocampal and Ch1-2 volumes were directly associated with spatial pattern separation performance while the entorhinal cortex operated on pattern separation indirectly through the hippocampus.
Smaller volumes of the hippocampus, entorhinal cortex, and basal forebrain Ch1-2 nuclei are linked to spatial pattern separation impairment in biomarker-defined early clinical AD and may contribute to AD-related spatial memory deficits.
海马体、内嗅皮层和基底前脑是受阿尔茨海默病（AD）影响的首批大脑结构之一。它们在空间模式分离中起着至关重要的作用，这是准确编码相似空间信息的关键过程。
我们旨在研究空间模式分离及其与海马体、内嗅皮层和投射到海马体的基底前脑核（内侧隔核和 Broca 垂直肢的斜角带 Ch1-2 核）的体积变化在 AD 的生物标志物定义的早期临床阶段的关联。
共招募了 98 名来自捷克大脑老化研究队列的老年人。由于 AD 导致的遗忘型轻度认知障碍（aMCI）患者（n = 44）、轻度 AD 痴呆患者（n = 31）和认知正常的老年人（CN；n = 23）接受了空间模式分离测试、全面认知评估和 MRI 脑容量测定。
与 CN 组相比，AD 的早期临床阶段的空间模式分离准确性较低（p < 0.001），并且随着疾病严重程度的增加而降低（CN＞aMCI 由于 AD＞AD 痴呆）。控制一般记忆和认知表现，人口统计学特征和心理因素并没有改变结果。海马体和 Ch1-2 体积与空间模式分离性能直接相关，而内嗅皮层通过海马体间接影响模式分离。
在生物标志物定义的 AD 早期临床中，海马体、内嗅皮层和基底前脑 Ch1-2 核的体积较小与空间模式分离障碍有关，可能导致 AD 相关的空间记忆缺陷。
