Table_1_Differential Progression of Regional Hippocampal Atrophy in Aging and Parkinson’s Disease.docx

Hippocampal subfields have different vulnerability to the degenerative processes related to aging, amnestic mild cognitive impairment (MCI) and Alzheimer’s disease (AD), but the temporal evolution in Parkinson’s disease (PD) is unknown. The purposes of the current work are to describe regional hippocampal changes over time in a sample of PD patients classified according to their baseline cognitive status and to relate these changes to verbal memory loss. T1-weighted images and verbal memory assessment were obtained at two separate time points (3.8 ± 0.4 years apart) from 28 PD with normal cognition (PD-NC), 16 PD with MCI (PD-MCI) and 21 healthy controls (HCs). FreeSurfer 6.0 automated pipeline was used to segment the hippocampus into 12 bilateral subregions. Memory functions were measured with Rey’s Auditory Verbal learning test (RAVLT). We found significant reductions in cornu ammonis 1 (CA1) over time in controls as well as in PD subgroups. Right whole-hippocampal volumes showed time effects in both PD groups but not in controls. PD-NC patients also displayed time effects in the left hippocampal tail and right parasubiculum. Regression analyses showed that specific hippocampal subfield volumes at time 1 predicted almost 60% of the variability in RAVLT delayed-recall score decline. Changes in several hippocampal subregions also showed predictive value for memory loss. In conclusion, CA1 changes in PD were similar to those that occur in normal aging, but PD patients also had more decline in both anterior and posterior hippocampal segments with a more pronounced atrophy of the right hemisphere. Hippocampal segments are better predictors of changes in memory performance than whole-hippocampal volumes.

海马亚区对衰老、遗忘型轻度认知障碍（amnestic mild cognitive impairment, MCI）与阿尔茨海默病（Alzheimer’s disease, AD）相关的退行性病变具有不同的易感性，但帕金森病（Parkinson’s disease, PD）中的时间演变特征尚不明确。本研究旨在基于基线认知状态对帕金森病患者进行分组，描述其海马结构随时间推移的区域性变化，并探讨这些变化与言语记忆减退的关联。本研究纳入28例认知正常的帕金森病患者（PD-NC）、16例帕金森病合并轻度认知障碍患者（PD-MCI）以及21例健康对照者（HCs），在两个时间点（间隔3.8±0.4年）分别采集其T1加权成像（T1-weighted images）数据并开展言语记忆评估。采用FreeSurfer 6.0自动化处理流程将海马分割为12个双侧亚区；言语记忆功能通过雷伊听觉语言学习测验（Rey’s Auditory Verbal learning test, RAVLT）进行评测。研究结果显示，对照组与各帕金森病亚组的海马角1（cornu ammonis 1, CA1）体积均随时间出现显著降低。两组帕金森病患者的右侧全海马体积均表现出显著的时间效应，而对照组未观察到此现象。PD-NC患者的左侧海马尾与右侧旁下托体积同样存在时间效应。回归分析表明，时间点1时的特定海马亚区体积可解释RAVLT延迟回忆得分下降近60%的变异度；多个海马亚区的体积变化也对记忆减退具有预测价值。综上，帕金森病患者的CA1变化与正常衰老过程中的改变相似，但帕金森病患者的海马前后节段均出现更为显著的萎缩，且右侧半球萎缩更为明显。相较于全海马体积，海马节段体积能更好地预测记忆功能的变化。