Journal Article

Cortical Thickness Changes After Computerized Working Memory Training in Patients With Mild Cognitive Impairment

Flak, Marianne M, Skranes, Jon, Madsen, Bengt-Ove, Bjuland, Knut Jørgen, Hernes, Susanne S, Hol, Haakon R, Rimol, Lars M, Ernst, Thomas, Chang, Linda, Løhaugen, Gro Christine Christensen, Engvig, Andreas

2022

Overview

Background: 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. Objective: 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. Secondly, we investigated the genotype effects on cortical thickness trajectories after WM training between these two training groups using longitudinal structural magnetic resonance imaging (MRI) analysis in Freesurfer. Method: MRI 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 five 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 analyses, a threshold was applied to yield an expected false discovery rate (FDR) of 5%. A secondary LME model investigated the effects of LMX1A and APOE-ε4 on cortical thickness trajectories after WM training. Results: 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 healthy adults. No significant structural cortical changes were found after training, regardless of training type, across all participants. However, LMX1A-AA carriers displayed increased cortical thickness trajectories or lack of decrease in 2 regions post-training compared to those with LMX1A-GG/GA. No training or training type effects were found in relation to the APOE-ε4 gene variants. Conclusion: MCI patients do not appear to show improved cortical thickness after WM training with either adaptive or non-adaptive training. These results were derived from a heterogeneous population of MCI participants. Our promising results of increased cortical thickness trajectory, suggesting greater neuroplasticity, in those with LMX1A-AA genotype need to be validated in future trials.

• Publisher: Frontiers Research Foundation
• Subject: Aging / Alzheimer's disease / Apolipoprotein E / Brain research / Clinical trials / Cognitive ability / Dementia / Genotypes / Hospitals / Intervention / Magnetic resonance imaging / Memory / Neuroplasticity / Neuropsychology / Older people / Short term memory / Statistical analysis