Stroke: Cerebral small vessel disease, oxygen metabolic stress and white matter damage are closely related

Dementia is one of the most important public health crises globally
.

Vascular -induced cognitive impairment and dementia are the second leading cause of dementia after Alzheimer's disease and include a variety of cerebrovascular disorders

Blood vessel

WMHs are a valuable imaging biomarker of CSVD because they are easily identifiable, ubiquitous, and strongly associated with clinical endpoints, including occurrence of stroke, stroke sequelae, cognitive impairment, and all-cause mortality
.

Furthermore, DTI indicators of compromised microstructural integrity, including low anisotropy (FA) and high mean diffusivity (MD), predict normal-appearing WM (NAWM) conversion to WMH

Although WMH may have multiple etiologies, it is mainly observed with advancing age and the development of hypertension
.

Although cerebrovascular risk factors are associated with WMH, most variants of WMH remain difficult to identify

hypertension

However, the results of population studies are conflicting
.

Hypertension alters the structure of cerebral vessels, leading to atherosclerosis and lipid softening, which in turn may lead to chronic hypoperfusion and ischemia

prevention

Spatial patterns of disease may shed light on the pathophysiology of CSVD
.

Notably, the WMH is biased towards the periventricular and deep white matter (WM), an area that overlaps the inner border zone of the brain

The WMH is biased towards the periventricular and deep white matter (WM), an area that overlaps the inner border zone of the brain

From this, Peter Kang et al.
, of Washington University School of Medicine, measured CBF to delineate physiological watersheds
.

In addition, regional CBF and oxygen extraction fraction (OEF) in CSVD patients were also investigated, focusing on the WM and physiological watershed regions

The core hypothesis is that watershed regions have the highest densities of WMH and impaired microstructural integrity and are associated with the highest OEF elevations
.

and further hypothesized that the NAWM surrounding the WMH would show elevated OEF, suggesting that hypoxia-ischemia may precede the development of the WMH

In this cross-sectional study conducted at an academic medical center in St.
Louis, Missouri, from 2016 to 2019, participants (aged >50 years) with a range of cerebrovascular risk factors underwent brain magnetic resonance imaging, using a sham Continuous arterial spin labeling (pseudocontinuous arterial spin labeling), asymmetric spin echo (asymmetric spin echo), FLAIR and diffusion tensor imaging to measure cerebral blood flow (CBF), OEF, WMH and WM integrity, respectively
.

They defined a physiologic watershed as an area in a young healthy population with a CBF below the 10th percentile of mean WM CBF
.

Linear regressions were performed to assess the relationship between CBF and OEF and structural and microscopic WM damage as defined by fluid-attenuated inversion recovery WMH and diffusion tensor imaging, respectively
.
ANOVA was finally performed to determine whether OEF increased close to WMH lesions
.

They found that, in a cohort of 42 people (aged 50-80 years), the physiological watershed area overlapped spatially with the area with the highest density of WMH lesions
.
As CBF decreased and OEF increased, WMH density also increased
.

Elevated OEF in the watershed was associated with greater WMH burden and microstructural disruption after adjusting for vascular risk factors
.

In contrast, WM and watershed CBF were not associated with WMH burden or microstructural disruption
.
Furthermore, in concentric circles close to the WMH lesions, OEF gradually increased and CBF decreased
.

The significance of this study lies in the discovery that chronic hypoxia-ischemia in the watershed region may contribute to the pathogenesis of cerebral small vessel disease and the development of WMH
.
Watershed OEF may serve as an imaging biomarker to identify individuals at risk for the progression of cerebral small vessel disease
.

Chronic hypoxia-ischemia in the watershed region may contribute to the pathogenesis of cerebral small vessel disease and the development of WMH

Original source:
[Kang P, Ying C, Chen Y, Ford AL, An H, Lee JM.
Oxygen Metabolic Stress and White Matter Injury in Patients With Cerebral Small Vessel Disease.
Stroke .
Published online December 10, 2021:STROKEAHA.
121.
035674.
doi:10.
1161/STROKEAHA.
121.
035674](https://doi.
org/10.
1161/STROKEAHA.
121.
035674)

Oxygen Metabolic Stress and White Matter Injury in Patients With Cerebral Small Vessel Disease.
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