Visible Virchow-Robin spaces (VRS) are commonly used markers for small vessel disease in aging and dementia.
However, as previous reports were based on subjective visual ratings, the goal of this ...project was to validate and apply an MRI-based quantitative measure of VRS as a potential neuroimaging biomarker.
A modified version of Lesion Explorer was applied to MRIs from Alzheimer's disease patients (AD: n = 203) and normal elderly controls (NC: n = 94). Inter-rater reliability, technique validity, group/gender differences, and correlations with other small vessel disease markers were examined (lacunes and white matter hyperintensities, WMH).
Inter-rater reliability and spatial congruence was excellent (ICC = 0.99, SI = 0.96), and VRS volumes were highly correlated with established rating scales (CS: ρ = 0.84, p < 0.001; BG: ρ = 0.75, p < 0.001). Compared to NC, AD had significantly greater volumes of WMH (p < 0.01), lacunes (p < 0.001), and VRS in the white matter (p < 0.01), but not in the basal ganglia (n.s.). Compared to women, demented and non-demented men had greater VRS in the white matter (p < 0.001), but not in the basal ganglia (n.s.). Additionally, VRS were correlated with lacunes and WMH, but only in AD (r = 0.3, p < 0.01).
Compared to women, men may be more susceptible to greater volumes of VRS, particularly in the white matter. RESULTS support the hypothesis that VRS in the white matter may be more related to AD-related vascular pathology compared to VRS found in the basal ganglia. Future work using this novel VRS segmentation tool will examine its potential utility as an imaging biomarker of vascular rather than parenchymal amyloid.
Although white matter hyperintensities (WMH), markers of cerebral small vessel disease (SVD), are believed to generally increase over time, some studies have shown sharp decreases after therapeutic ...intervention, suggesting that WMH progression may be more dynamic than previously thought. Our primary goal was to examine dynamic progression of WMH in a real-world sample of Alzheimer's disease (AD) patients and normal elderly (NC), with varying degrees of SVD. WMH volumes from serial magnetic resonance imaging (MRI; mean = 1.8 years) were measured from NC (n = 44) and AD patients (n = 113) with high and low SVD burden. Dynamic progression for each individual was measured using spatial overlap images to assess shrinkage, growth, and stable WMH volumes. Significant group differences were found for shrinkage (p < 0.001), growth (p < 0.001) and stable (p < 0.001) WMH, where the AD high SVD group showed the largest changes relative to low SVD and NC. Our results suggest spatial progression measured at the individual patient level may be more sensitive to the dynamic nature of WMH.
Although the brain lacks conventional lymphatic vessels found in peripheral tissue, evidence suggests that the space surrounding the vasculature serves a similar role in the clearance of fluid and ...metabolic waste from the brain. With aging, neurodegeneration, and cerebrovascular disease, these microscopic perivascular spaces can become enlarged, allowing for visualization and quantification on structural MRI. The purpose of this review is to: (i) describe some of the recent pre-clinical findings from basic science that shed light on the potential neurophysiological mechanisms driving glymphatic and perivascular waste clearance, (ii) review some of the pathobiological etiologies that may lead to MRI-visible enlarged perivascular spaces (ePVS), (iii) describe the possible clinical implications of ePVS, (iv) evaluate existing qualitative and quantitative techniques used for measuring ePVS burden, and (v) propose future avenues of research that may improve our understanding of this potential clinical neuroimaging biomarker for fluid and metabolic waste clearance dysfunction in neurodegenerative and neurovascular diseases.
To synthesize quantitatively the mild cognitive impairment (MCI) literature with respect to the relationship between cognitive reserve and neuropsychological and functional outcomes.
Participants ...with a diagnosis of MCI (total n = 7,871; 53% female) were included in this random-effects meta-analysis. Neuropsychological measures were combined into composite scores (e.g., overall cognitive functioning, screening measures, memory, language, visuospatial, attention/processing speed/working memory, executive functioning, and motor functioning). Measures assessing real-world abilities were combined into an activities of daily living (ADL) composite.
Nearly all neuropsychological composite values were significantly correlated with education, with effect sizes ranging from small to moderate. The effect between overall neuropsychological functioning and occupation was weak and varied by cognitive domain. For cognitively stimulating leisure activity, only overall neuropsychological functioning demonstrated a significant relationship, with a weak effect size (r = .16). In contrast, ADLs were most strongly associated with leisure experience (r = .27), with a negligible relationship with education (r = 0.08) and occupation (r = 0.09).
Of the cognitive reserve proxies examined in this study, participation in leisure activity had the largest magnitude of effect size with ADL functioning. This was in stark contrast to the negligible relationship found for education and occupation. Although education has been widely considered the most important cognitive reserve proxy with respect to cognition, this work questions whether other lifestyle factors may play a more important role in preserving real world functioning.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
To evaluate whether cerebrospinal fluid biomarkers, apolipoprotein e4, neuroimaging abnormalities, and neuropsychological data differentially predict progression from mild cognitive impairment (MCI) ...to dementia for men and women.
Participants who were diagnosed with MCI at baseline (
= 449) were classified as either progressing to Alzheimer's dementia at follow-up or as not progressing. Men and women were first compared using bivariate analyses. Sex-stratified Cox proportional hazard regressions were performed examining the relationship between baseline data and the likelihood of progressing to dementia. Sex interactions were subsequently examined.
Cox proportional hazard regression controlling for age and education indicated that all variables significantly predicted subsequent progression to dementia for men and women. Sex interactions indicated that only Rey Auditory Verbal Learning Test (RAVLT) delayed recall and Functional Activities Questionnaire (FAQ) were significantly stronger risk factors for women. When all variables were entered into a fully adjusted model, significant risk factors for women were Aβ42, hippocampal volume, RAVLT delayed recall, Boston Naming Test, and FAQ. In contrast, for men, Aβ42, p-tau181, p-tau181/Aβ42, hippocampal volume, category fluency and FAQ were significant risk factors. Interactions with sex were only significant for p-tau181/Aβ42 and RAVLT delayed recall for the fully adjusted model.
Men and women with MCI may to differ for which factors predict subsequent dementia although future analyses with greater power are needed to evaluate sex differences. We hypothesize that brain and cognitive reserve theories may partially explain these findings.
To test the hypothesis that enlarged Virchow-Robin space volumes (VRS) are associated with objective measures of poor quality sleep.
Retrospective cross-sectional study.
Sunnybrook Health Sciences ...Centre.
Twenty-six patients being evaluated for cerebrovascular disease were assessed using polysomnography and high-resolution structural magnetic resonance imaging.
Regionalized VRS were quantified from three-dimensional high-resolution magnetic resonance imaging and correlated with measures of polysomnography-derived sleep parameters while controlling for age, stroke volume, body mass index, systolic blood pressure, and ventricular cerebrospinal fluid volume. Sleep efficiency was negatively correlated with total VRS (rho = -0.47, P = 0.03) and basal ganglia VRS (rho = -0.54, P = 0.01), whereas wake after sleep onset was positively correlated with basal ganglia VRS (rho = 0.52, P = 0.02). Furthermore, VRS in the basal ganglia were negatively correlated with duration of N3 (rho = -0.53, P = 0.01).
These preliminary results suggest that sleep may play a role in perivascular clearance in ischemic brain disease, and invite future research into the potential relevance of Virchow-Robin spaces as an imaging biomarker for nocturnal metabolite clearance.
Objective
Previous research suggests that overall experience participating in instrumental activities of daily living (IADLs) is associated with reduced IADL impairment in individuals with mild ...cognitive impairment, possibly because of an increased functional reserve. Given that difficulties managing finances tend to occur with mild cognitive impairment, this study explores whether experience managing one's finances is associated with independence across various IADLs.
Methods
Participants with a screen or baseline diagnosis of mild cognitive impairment (n = 862) were taken from the Alzheimer's Disease Neuroimaging Initiative study. Functional dependence and experience were quantified from the Functional Activities Questionnaire.
Results
No group differences between those with and without financial management experience existed in Mini‐Mental State Examination scores, age, and years of education, although women were more likely to have experience managing finances (P < .001). Final chi‐square analyses suggest that financial management experience is significantly associated with greater independence in the ability to follow TV, books, or magazines (P = .009) and remember appointments and important dates (P = .002).
Conclusions
Individuals who are rated as having experience in managing their finances were also rated as being less dependent in their ability to follow and understand TV and books and in their ability to remember appointments and important dates. Neither causation nor the mechanisms underlying this relationship can be discerned from these analyses. Therefore, further research is needed to investigate whether engaging in financial tasks protects against early financial impairment, potentially through an increased functional reserve.
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