scholarly journals A population neuroscience approach to the study of cerebral small vessel disease in midlife and late life: an invited review

2018 ◽  
Vol 314 (6) ◽  
pp. H1117-H1136 ◽  
Author(s):  
Dana R. Jorgensen ◽  
C. Elizabeth Shaaban ◽  
Clayton A. Wiley ◽  
Peter J. Gianaros ◽  
Joseph Mettenburg ◽  
...  

Aging in later life engenders numerous changes to the cerebral microvasculature. Such changes can remain clinically silent but are associated with greater risk for negative health outcomes over time. Knowledge is limited about the pathogenesis, prevention, and treatment of potentially detrimental changes in the cerebral microvasculature that occur with advancing age. In this review, we summarize literature on aging of the cerebral microvasculature, and we propose a conceptual framework to fill existing research gaps and advance future work on this heterogeneous phenomenon. We propose that the major gaps in this area are attributable to an incomplete characterization of cerebrovascular pathology, the populations being studied, and the temporality of exposure to risk factors. Specifically, currently available measures of age-related cerebral microvasculature changes are indirect, primarily related to parenchymal damage rather than direct quantification of small vessel damage, limiting the understanding of cerebral small vessel disease (cSVD) itself. Moreover, studies seldom account for variability in the health-related conditions or interactions with risk factors, which are likely determinants of cSVD pathogenesis. Finally, study designs are predominantly cross-sectional and/or have relied on single time point measures, leaving no clear evidence of time trajectories of risk factors or of change in cerebral microvasculature. We argue that more resources should be invested in 1) developing methodological approaches and basic science models to better understand the pathogenic and etiological nature of age-related brain microvascular diseases and 2) implementing state-of-the-science population study designs that account for the temporal evolution of cerebral microvascular changes in diverse populations across the lifespan.

2019 ◽  
Vol 75 (4) ◽  
pp. 696-701
Author(s):  
Caterina Rosano ◽  
Andrea L Metti ◽  
Andrea L Rosso ◽  
Stephanie Studenski ◽  
Nicolaas I Bohnen

Abstract Objective Parkinsonian motor signs are common and disabling in older adults without Parkinson’s disease (PD), but its risk factors are not completely understood. We assessed the influence of striatal dopamine levels, cerebral small vessel disease, and other factors on age-related parkinsonian motor signs in non-PD adults. Methods Striatal dopamine transporter (DAT) binding was quantified via [11C]-CFT positron emission tomography in 87 neurologically intact adults (20–85 years, 57.47% female) with concurrent data on: Unified Parkinson’s Disease Rating Scale motor (UPDRSm), white matter hyperintensities (WMH), and other risk factors (grip strength, vibratory sensitivity, cardio- and cerebro-vascular comorbidities). Sex-adjusted nonparametric models first estimated the associations of age, DAT, WMH, and other factors with UPDRSm; next, interactions of age by DAT, WMH, or other factors were tested. To quantify the influence of DAT, WMH, and other risk factors on the main association of age with UPDRSm, multivariable mediation models with bootstrapped confidence intervals (CI) were used. Results Older age, lower DAT, higher WMH, and worse risk factors significantly predicted worse UPDRSm (sex-adjusted p < .04 for all). DAT, but not WMH or other factors, positively and significantly interacted with age (p = .02). DAT significantly reduced the age-UPDRSm association by 30% (results of fully adjusted mediation model: indirect effect: 0.027; bootstrapped 95% CI: 0.0007, 0.074). Conclusions Striatal dopamine appears to influence to some extent the relationship between age and parkinsonian signs. However, much of the variance of parkinsonian signs appears unexplained. Longitudinal studies to elucidate the multifactorial causes of this common condition of older age are warranted.


2018 ◽  
Author(s):  
Ayan Dey ◽  
Vessela Stamenova ◽  
Agnes Bacopulos ◽  
Nivethika Jeyakumar ◽  
Gary R. Turner ◽  
...  

Some degree of ischemic injury to white matter tracts occurs naturally with age and is visible on magnetic resonance imaging as focal or confluent white matter hyperintensities (WMHs). Its relationship to cognition, however, remains unclear. To explore this, community-dwelling adults between the ages 55-80 years old completed structural imaging, neuropsychological testing, and questionnaires to provide objective measures and subjective experience of executive functioning. Volumetric lesion burden derived from structural MRI identified those with significant WMH burden (~10 cubic cm). Half of those recruited met this criterion and were designated as the cerebral small vessel disease (CSVD) group. Subjective complaints but not objective test scores differentiated adults with and without CSVD. Hierarchical clustering revealed two CSVD subgroups that differentiated those with impaired versus preserved executive function relative to controls. Overall these results provide some explanation for behavioural heterogeneity often observed in studies of age-related white matter changes. They also support the use of questionnaires to assess subjective complaints that may be able to detect subtle effects of pathology not evident on standardized cognitive scores.


Author(s):  
E.I. Kremneva ◽  
B.M. Akhmetzyanov ◽  
L.A. Dobrynina ◽  
M.V. Krotenkova

Hemodynamic parameters of blood and cerebrospinal fluid (CSF) flow can be measured in vivo using phase-contrast MRI (PC-MRI). This opens new horizons for studying the mechanisms implicated in the development and progression of age-related cerebral small vessel disease (SVD). In this paper, we analyze associations between cerebral arterial, venous and CSF flow impairments and SVD features visible on MRI. The study was carried out in 96 patients with SVD (aged 60.91 ± 6.57 years) and 23 healthy volunteers (59.13 ± 6.56 years). The protocol of the MRI examination included routine MRI sequences (T2, FLAIR, T1, SWI, and DWI) applied to assess the severity of brain damage according to STRIVE advisory standards and PC-MRI used to quantify blood flow in the major arteries and veins of the neck, the straight and upper sagittal sinuses, and CSF flow at the aqueduct level. We analyzed the associations between linear and volumetric parameters of blood/CSF flow and the degree of brain matter damage using the Fazekas scale. We observed a reduction in tABF, stVBF, sssVBF, aqLF, Saq, and ICC values and a rise in Pi associated with WMH progression, as well as a gradual decline in tABF and an increase in Pi, Saq and ICC associated with a growing number of lacunes (р < 0.05). Patients with early (< 5) MB had lower sssVBF and stVBF rates in comparison with patients without MB; aqLF, Saq, and ICC values were elevated in patients with 5 to 10 MB, as compared to patients without MB or early (< 5) MB. The established associations between MRI findings in patients with SVD and blood/CSF flow impairments suggest the important role of mechanisms implicated in the disruption of Monro–Kellie intracranial homeostasis in promoting SVD.


Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Susanna Melkas ◽  
Sami Curtze ◽  
Gerli Sibolt ◽  
Niku K Oksala ◽  
Jukka Putaala ◽  
...  

Background: Association between high homocysteine level and cerebral small-vessel disease has been implicated in cross-sectional studies, but results from longitudinal studies have been less clear. The aim of this study was to investigate whether homocysteine level at 3-months poststroke relates to the occurrence of white matter changes (WMC), the surrogate of cerebral small-vessel disease. We also investigated whether it relates to the prognosis after ischemic stroke regarding the risk of dementia at 3-months and mortality in long-term follow-up. Methods: A total of 321 consecutive acute ischemic stroke patients aged 55 to 85 were included in the study and followed up to 12 years. Plasma homocysteine level and occurrence of WMC in MRI were measured 3 months poststroke and dementia according to DSM-III was evaluated at the same time. Findings: The median homocysteine level was 13.50 μmol/l (interquartile range [IQR] 10.60-18.50 μmol/l). Total of 81 patients (25.2%) had homocysteine level above 18.50 μmol/l. In logistic regression analysis, homocysteine level above 18.50 μmol/l was not associated with severe WMC nor with dementia at 3 months poststroke. In Kaplan-Meier analysis, homocysteine level above 18.50 μmol/l was not associated with survival in 12-year follow-up. For further analysis, the group was divided in quartiles according to homocysteine level. The quartiles did not differ in occurrence of severe WMC at baseline, in the risk of dementia at 3 months, nor in the risk of mortality in 12-year follow-up. Interpretation: In our poststroke cohort homocysteine level is not associated with WMC. Further, it does not relate to impaired prognosis manifested as dementia at 3 months or mortality in 12-year follow-up.


2020 ◽  
Vol 82 (1) ◽  
pp. 275-295 ◽  
Author(s):  
T. Michael De Silva ◽  
Frank M. Faraci

Cerebral small vessel disease (SVD) is characterized by changes in the pial and parenchymal microcirculations. SVD produces reductions in cerebral blood flow and impaired blood-brain barrier function, which are leading contributors to age-related reductions in brain health. End-organ effects are diverse, resulting in both cognitive and noncognitive deficits. Underlying phenotypes and mechanisms are multifactorial, with no specific treatments at this time. Despite consequences that are already considerable, the impact of SVD is predicted to increase substantially with the growing aging population. In the face of this health challenge, the basic biology, pathogenesis, and determinants of SVD are poorly defined. This review summarizes recent progress and concepts in this area, highlighting key findings and some major unanswered questions. We focus on phenotypes and mechanisms that underlie microvascular aging, the greatest risk factor for cerebrovascular disease and its subsequent effects.


2019 ◽  
Vol 78 (11) ◽  
pp. 1066-1072 ◽  
Author(s):  
Emma J Norton ◽  
Leslie R Bridges ◽  
Lawrence C Kenyon ◽  
Margaret M Esiri ◽  
Dorothy C Bennett ◽  
...  

Abstract Cerebral small vessel disease (cSVD) in penetrating arteries is a major cause of age-related morbidity. Cellular senescence is a molecular process targeted by novel senolytic drugs. We quantified senescence in penetrating arteries and tested whether myocyte senescence was associated with cSVD. We immunolabeled subcortical white matter of older persons (age 80–96 years, n = 60) with minimal AD, using antibodies to 2 established senescence markers (H3K9me3, γH2AX) and a myocyte marker (hSMM). Within the walls of penetrating arteries (20–300 µm), we quantified senescence-associated heterochromatic foci (SAHF)-positive nuclei, cell density (nuclei/µm2), and sclerotic index (SI). Senescent-appearing mural cells were present in small arteries of all cases. cSVD cases exhibited a lower proportion of senescent-appearing cells and lower area fraction (AF%) of SAHF-positive nuclei compared to controls (p = 0.014, 0.016, respectively). cSVD severity and SI both correlated negatively with AF% (p = 0.013, 0.002, respectively). Mural cell density was lower (p < 0.001) and SI higher (p < 0.001) in cSVD, relative to controls. In conclusion, senescent myocyte-like cells were universal in penetrating arteries of an AD-free cohort aged 80 years and older. Senescent-appearing nuclei were more common in persons aged 80 years and older without cSVD compared to cSVD cases, indicating caution in senolytic drug prescribing. Myocyte senescence and cSVD may represent alternative vessel fates in the aging human brain.


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