Hol Haakon R, Flak Marianne M, Chang Linda, Løhaugen Gro Christine Christensen, Bjuland Knut Jørgen, Rimol Lars M, Engvig Andreas, Skranes Jon, Ernst Thomas, Madsen Bengt-Ove, Hernes Susanne S
Department of Radiology, Sørlandet Hospital, Arendal, Norway.
Department of Radiology, Oslo University Hospital, Oslo, Norway.
Front Aging Neurosci. 2022 Apr 4;14:796110. doi: 10.3389/fnagi.2022.796110. eCollection 2022.
Adaptive computerized working memory (WM) training has shown favorable effects on cerebral cortical thickness as compared to non-adaptive training in healthy individuals. However, knowledge of WM training-related morphological changes in mild cognitive impairment (MCI) is limited.
The primary objective of this double-blind randomized study was to investigate differences in longitudinal cortical thickness trajectories after adaptive and non-adaptive WM training in patients with MCI. We also investigated the genotype effects on cortical thickness trajectories after WM training combining these two training groups using longitudinal structural magnetic resonance imaging (MRI) analysis in Freesurfer.
Magnetic resonance imaging acquisition at 1.5 T were performed at baseline, and after four- and 16-weeks post training. A total of 81 individuals with MCI accepted invitations to undergo 25 training sessions over 5 weeks. Longitudinal Linear Mixed effect models investigated the effect of adaptive vs. non-adaptive WM training. The LME model was fitted for each location (vertex). On all statistical analyzes, a threshold was applied to yield an expected false discovery rate (FDR) of 5%. A secondary LME model investigated the effects of 1A and ε4 on cortical thickness trajectories after WM training.
A total of 62 participants/patients completed the 25 training sessions. Structural MRI showed no group difference between the two training regimes in our MCI patients, contrary to previous reports in cognitively healthy adults. No significant structural cortical changes were found after training, regardless of training type, across all participants. However, 1A-AA carriers displayed increased cortical thickness trajectories or lack of decrease in two regions post-training compared to those with 1A-GG/GA. No training or training type effects were found in relation to the -ε4 gene variants.
The MCI patients in our study, did not have improved cortical thickness after WM training with either adaptive or non-adaptive training. These results were derived from a heterogeneous population of MCI participants. The lack of changes in the cortical thickness trajectory after WM training may also suggest the lack of atrophy during this follow-up period. Our promising results of increased cortical thickness trajectory, suggesting greater neuroplasticity, in those with 1A-AA genotype need to be validated in future trials.
与非适应性训练相比，适应性计算机化工作记忆（WM）训练对健康个体的大脑皮质厚度显示出有利影响。然而，关于轻度认知障碍（MCI）中与WM训练相关的形态学变化的知识有限。
这项双盲随机研究的主要目的是调查MCI患者在适应性和非适应性WM训练后纵向皮质厚度轨迹的差异。我们还使用Freesurfer中的纵向结构磁共振成像（MRI）分析，结合这两个训练组，研究了WM训练后基因型对皮质厚度轨迹的影响。
在基线以及训练后4周和16周进行1.5T磁共振成像采集。共有81名MCI个体接受邀请，在5周内进行25次训练。纵向线性混合效应模型研究了适应性与非适应性WM训练的效果。对每个位置（顶点）拟合LME模型。在所有统计分析中，应用一个阈值以产生5%的预期错误发现率（FDR）。第二个LME模型研究了1A和ε4对WM训练后皮质厚度轨迹的影响。
共有62名参与者/患者完成了25次训练。与认知健康成年人的先前报告相反，结构MRI显示我们的MCI患者在两种训练方式之间没有组间差异。在所有参与者中，无论训练类型如何，训练后均未发现明显的皮质结构变化。然而，与携带1A-GG/GA的人相比，1A-AA携带者在训练后两个区域的皮质厚度轨迹增加或没有下降。未发现与-ε4基因变体相关的训练或训练类型效应。
我们研究中的MCI患者在进行适应性或非适应性WM训练后，皮质厚度没有改善。这些结果来自MCI参与者的异质性群体。WM训练后皮质厚度轨迹缺乏变化也可能表明在此随访期间没有萎缩。我们在1A-AA基因型个体中观察到的皮质厚度轨迹增加的有前景的结果，提示更大的神经可塑性，需要在未来的试验中得到验证。
