Regional leukoaraiosis and cognition in non-demented older adults

Abstract

Frontal lobe-executive functions are heavily dependent on distal white matter connectivity. Even with healthy aging there is an increase in leukoaraiosis that might interrupt this connectivity. The goal of this study is to learn 1) the location, depth, and percentage of leukoaraiosis in white matter among a sample of non-demented older adults and 2) associations between these leukoarioasis metrics and composites of cognitive efficiency (processing speed, working memory, and inhibitory function), and episodic memory. Participants were 154 non-demented older adults (age range 60-85) who completed a brain MRI and neuropsychological testing on the same day. Brain MRIs were segmented via Freesurfer and white matter leukoaraiosis depth segmentations was based on published criteria. On average, leukoaraiosis occupied 1 % of total white matter. There was no difference in LA distribution in the frontal (1.12%), parietal (1.10%), and occipital (0.95%) lobes; there was less LA load within the temporal lobe (0.23%). For cortical depth, leukoaraiosis was predominantly in the periventricular region (3.39%; deep 1.46%, infracortical 0.15%). Only increasing frontal lobe and periventricular leukoaraiosis were associated with a reduction in processing speed, working memory, and inhibitory function. Despite the general presence of LA throughout the brain, only frontal and periventricular LA contributed to the speeded and mental manipulation of executive functioning. This study provides a normative description of LA for non-demented adults to use as a comparison to more disease samples.

Subcortical Ischemic Vascular Cognitive Impairment: Insights from Reaction Time Measures

“…There is a robust association between slowed behavioral RT (particularly that related to executive function) and reduced structural and functional integrity of white matter at both regional and global levels [1,[17][18][19][21][22][23][24][25][26][27][28]. Predictably, therefore, RT slowing appears to be a significant clinical and research characteristic of SIVCI.…”

“…Cerebral small vessel disease in older adulthood, typically appearing as periventricular white matter lesions or leukoaraiosis (LA) [1] on neuroimaging, can result in the development of subcortical ischemic vascular cognitive impairment (SIVCI). This can manifest initially as subjective or subclinical cognitive decline, and then later as minor or major neurocognitive disorder (dementia) [2][3][4][5][6][7][8][9][10].…”

Reaction Time and Visible White Matter Lesions in Subcortical Ischemic Vascular Cognitive Impairment

“…Nevertheless, it can be difficult to determine the clinical extent and relevance of white matter lesions in SIVCI particularly as their full extent may not be visible on diagnostic CT/MRI scans. In the research domain, a significant body of evidence supports a strong association between pathological brain changes, including distributed or global structural and functional breakdown in white matter, and cognitive decline [5][6][7][8][9][10][11][12][13], particularly behavioral reaction time (RT) [6][7][8][9][10][14][15][16][17][18][19][20][21][22][23][24][25]. Testing RT may therefore be an important adjunct to the diagnosis of SIVCI and the determination of disease load that may not be fully represented by the level of periventricular white matter visible on diagnostic scans.…”

Recent Advance of Enzyme Targets for the Management of Vascular Dementia

“…In addition, the central cholinergic system is plays a key role in the neuromodulatory action; vasomotor control; cerebral circulation of blood; and cognitive function. The basal prosencephalon and routes of their projections are the main areas for the cognitive function [32]. The vascular lesion of this area alters the cholinergic neuronal pathways via acetylcholinesterase and cholinergic neurotransmitter action.…”

“…The denervation of this cholinergic neuron plays a role in the development of cholinergic hypofunction and vascular dysfunction. Which leads to enhance the VaD associated cognitive dysfunction [32]. The administration of cholinesterase inhibitors like donepezil, galantamine and rivastigmine are symptomatically relieved the symptoms of VaD in human [33].…”