%0 Journal Article %J J Alzheimers Dis %D 2023 %T Impact of Computerized Cognitive Training on Default Mode Network Connectivity in Subjects at Risk for Alzheimer's Disease: A 78-week Randomized Controlled Trial. %A Petrella, Jeffrey R %A Michael, Andrew M %A Qian, Min %A Nwosu, Adaora %A Sneed, Joel %A Goldberg, Terry E %A Devanand, Davangere P %A Doraiswamy, P Murali %K Alzheimer Disease %K Brain %K Cognitive Dysfunction %K Cognitive Training %K Default Mode Network %K Humans %K Magnetic Resonance Imaging %K Nerve Net %X

BACKGROUND: Mild cognitive impairment (MCI) represents a high risk group for Alzheimer's disease (AD). Computerized Cognitive Games Training (CCT) is an investigational strategy to improve targeted functions in MCI through the modulation of cognitive networks.

OBJECTIVE: The goal of this study was to examine the effect of CCT versus a non-targeted active brain exercise on functional cognitive networks.

METHODS: 107 patients with MCI were randomized to CCT or web-based crossword puzzles. Resting-state functional MRI (fMRI) was obtained at baseline and 18 months to evaluate differences in fMRI measured within- and between-network functional connectivity (FC) of the default mode network (DMN) and other large-scale brain networks: the executive control, salience, and sensorimotor networks.

RESULTS: There were no differences between crosswords and games in the primary outcome, within-network DMN FC across all subjects. However, secondary analyses suggest differential effects on between-network connectivity involving the DMN and SLN, and within-network connectivity of the DMN in subjects with late MCI. Paradoxically, in both cases, there was a decrease in FC for games and an increase for the crosswords control (p < 0.05), accompanied by lesser cognitive decline in the crosswords group.

CONCLUSION: Results do not support a differential impact on within-network DMN FC between games and crossword puzzle interventions. However, crossword puzzles might result in cognitively beneficial remodeling between the DMN and other networks in more severely impaired MCI subjects, parallel to the observed clinical benefits.

%B J Alzheimers Dis %V 91 %P 483-494 %8 2023 %G eng %N 1 %R 10.3233/JAD-220946 %0 Journal Article %J J Alzheimers Dis %D 2016 %T Anti-Correlated Cerebrospinal Fluid Biomarker Trajectories in Preclinical Alzheimer's Disease. %A Gomar, Jesus J %A Conejero-Goldberg, Concepcion %A Davies, Peter %A Goldberg, Terry E %K Adult %K Aged %K Aged, 80 and over %K Alzheimer Disease %K Amyloid beta-Peptides %K Atrophy %K Brain %K Disease Progression %K Female %K Humans %K Longitudinal Studies %K Magnetic Resonance Imaging %K Male %K Middle Aged %K Neuropsychological Tests %K Peptide Fragments %K Prodromal Symptoms %K Regression Analysis %K Statistics, Nonparametric %K tau Proteins %X

BACKGROUND: The earliest stage of preclinical Alzheimer's disease (AD) is defined by low levels of cerebrospinal fluid (CSF) amyloid-β (Aβ42). However, covariance in longitudinal dynamic change of Aβ42 and tau in incipient preclinical AD is poorly understood.

OBJECTIVE: To examine dynamic interrelationships between Aβ42 and tau in preclinical AD.

METHODS: We followed 47 cognitively intact participants (CI) with available CSF data over four years in ADNI. Based on longitudinal Aβ42 levels in CSF, CI were classified into three groups: 1) Aβ42 stable with normal levels of Aβ42 over time (n = 15); 2) Aβ42 declining with normal Aβ42 levels at baseline but showing decline over time (n = 14); and 3) Aβ42 levels consistently abnormal (n = 18).

RESULTS: In the Aβ42 declining group, suggestive of incipient preclinical AD, CSF phosphorylated tau (p-tau) showed a similar longitudinal pattern of increasing abnormality over time (p = 0.0001). Correlation between longitudinal slopes of Aβ42 and p-tau confirmed that both trajectories were anti-correlated (rho = -0.60; p = 0.02). Regression analysis showed that Aβ42 slope (decreasing Aβ42) predicted p-tau slope (increasing p-tau) (R2 = 0.47, p = 0.03). Atrophy in the hippocampus was predicted by the interaction of Aβ42 and p-tau slopes (p <  0.0001) only in this incipient preclinical AD group. In all groups combined, memory decline was predicted by p-tau.

CONCLUSIONS: The evolution of Aβ42 and p-tau CSF biomarkers in CI subjects follows an anti-correlated trajectory, i.e., as Aβ42 declined, p-tau increased, and thus was suggestive of strong temporal coincidence. Rapid pathogenic cross-talk between Aβ42 and p-tau thus may be evident in very early stages of preclinical AD.

%B J Alzheimers Dis %V 51 %P 1085-97 %8 2016 %G eng %N 4 %1 http://www.ncbi.nlm.nih.gov/pubmed/26967213?dopt=Abstract %R 10.3233/JAD-150937