White Matter Hyperintensity Load Modulates Brain Morphometry and Brain Connectivity in Healthy Adults: A Neuroplastic Mechanism?

Abstract

White matter hyperintensities (WMHs) are acquired lesions that accumulate and disrupt neuron-to-neuron connectivity. We tested the associations between WMH load and (1) regional grey matter volumes and (2) functional connectivity of resting-state networks, in a sample of 51 healthy adults. Specifically, we focused on the positive associations (more damage, more volume/connectivity) to investigate a potential route of adaptive plasticity. WMHs were quantified with an automated procedure. Voxel-based morphometry was carried out to model grey matter. An independent component analysis was run to extract the anterior and posterior default-mode network, the salience network, the left and right frontoparietal networks, and the visual network. Each model was corrected for age, global levels of atrophy, and indices of brain and cognitive reserve. Positive associations were found with morphometry and functional connectivity of the anterior default-mode network and salience network. Within the anterior default-mode network, an association was found in the left mediotemporal-limbic complex. Within the salience network, an association was found in the right parietal cortex. The findings support the suggestion that, even in the absence of overt disease, the brain actuates a compensatory (neuroplastic) response to the accumulation of WMH, leading to increases in regional grey matter and modified functional connectivity.

Attention-Related Brain Activation Is Altered in Older Adults With White Matter Hyperintensities Using Multi-Echo fMRI

“…This relationship reinforces the link between task performance and cognitive demand in HOA ( Cabeza et al, 2002 ), and highlights a decoupling of performance and neurovascular response in WMH. Our findings are consistent with aspects of neural network theories, in which accumulation of WMH can impact gray matter resting-state/task-based functional connectivity ( De Marco et al, 2017 ) and thus compensatory recruitment ( Lockhart et al, 2015 ; Dey et al, 2016 ). Indeed, cholinergic fibers are necessary for fronto-parietal, default mode network connections ( Cheng et al, 2012 ) and anterior-posterior coherences ( Moretti et al, 2008 ; Babiloni et al, 2009 ).…”

White matter hyperintensities are linked to future cognitive decline in de novo Parkinson's disease patients

“…The ranges of the WMH loads found in this study for both control and de novo PD populations (mean value of 7 CCs = 0.37% of the total intracranial volume) were similar to values reported in other normal aging studies, suggesting that similar trends of decline can be expected in such populations as well ( De Marco et al, 2017 ; Huang et al, 2018 ; Wiseman et al, n.d. ; Zhang et al, 2018 ).…”

Up-regulation of DMN Connectivity in Mild Cognitive Impairment Via Network-based Cognitive Training

“…Furthermore, the Lesion Segmentation Tool [ 28 ] was used to extract the global load (expressed in ml) of periventricular and deep white matter hyperintensities. This was in turn converted into a percentage of the global intracranial volume, as carried out in a recent study [ 29 ]. No difference was found between the two conditions.…”