Vascular dementia in leukoaraiosis may be a consequence of capillary loss not only in the lesions, but in normal-appearing white matter and cortex as well.

Department of Radiology, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA.
Journal of the Neurological Sciences (Impact Factor: 2.24). 07/2007; 257(1-2):62-6. DOI: 10.1016/j.jns.2007.01.015
Source: PubMed

ABSTRACT We investigated capillary density in 12 subjects with leukoaraiosis (LA), in 9 age-matched normal subjects, in 7 cases of Alzheimer's disease (AD), and 4 after whole-brain irradiation for brain tumors. In the LA study (which as been published), autopsy brains were evaluated by MRI. The presence of LA was indicated by confluent or patchy areas of hyperintensity in the deep white matter. We employed a stereology method using computerized image processing and analysis to determine microvascular density. Afferent vessels (arterioles and capillaries, but not veins or venules) were stained for alkaline phosphatase in 100 microm thick celloidin sections. Microvascular density in LA lesions in the deep white matter (2.56%) was significantly lower than in the corresponding deep white matter of normal subjects (3.20%, p=0.0180). LA subjects demonstrated decreased vascular density at early ages (55-65 years) when compared to normal subjects. Our findings indicate that LA affects the brain globally, with capillary loss, although the parenchymal damage is found primarily in the deep white matter. In ongoing studies of the deep white matter in AD brains, we found a pattern of decreased vascular density compared to normal, as well as an age-related decline. In the four irradiated brains, we found very low vessel densities, similar to those found in LA, without an additional age-related decline.

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    ABSTRACT: BACKGROUND AND PURPOSE: Previous pathological studies in humans or in animal models have shown alterations of small arteries and veins within white matter lesions in cerebral small vessel disease. We aimed to evaluate in vivo, the integrity of the cerebral venous network using high-resolution MRI both within and outside white matter hyperintensities in cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). METHODS: High-resolution T2*-weighted images were obtained at 7-T in 13 CADASIL patients with no or only mild symptoms and 13 age- and sex-matched controls. Macroscopic veins were automatically counted in the centrum semiovale and compared between patients and controls. In addition, T2* was compared between groups in the normal-appearing white matter. RESULTS: Vein density was found lower in CADASIL patients compared with that in controls (-14.6% in patients, P<0.001). This was detected both within and outside white matter hyperintensities. Mean T2*, that is presumably inversely related to the venous density, was also found increased in normal-appearing white matter of patients (+7.2%, P=0.006). All results were independent from the extent of white matter hyperintensities. CONCLUSIONS: A significant reduction in the number of visible veins was observed in the centrum semiovale of CADASIL patients both within and outside white matter hyperintensities, together with an increase of T2* in the normal-appearing white matter. Additional studies are needed to decipher the exact implication of such vasculature changes in the appearance of white matter lesions.
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    ABSTRACT: Recent data suggest that early symptoms may be related to cortex alterations in CADASIL (Cerebral Autosomal-Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy), a monogenic model of cerebral small vessel disease (SVD). The aim of this study was to investigate cortical alterations using both high-resolution T2* acquisitions obtained with 7 Tesla MRI and structural T1 images with 3 Tesla MRI in CADASIL patients with no or only mild symptomatology (modified Rankin's scale ≤1 and Mini Mental State Examination (MMSE) ≥24).
    PLoS ONE 01/2014; 9(8):e106311. · 3.53 Impact Factor
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    ABSTRACT: This study aimed to investigate the effect of exercise training on age-induced microvascular alterations in the brain. Additionally, the association with the protein levels of vascular endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS) was also assessed. Male Wistar rats were divided into four groups: sedentary-young (SE-Young, n = 5), sedentary aged (SE-Aged, n = 8), immersed-aged (IM-Aged, n = 5), and exercise trained-aged (ET-Aged, 60 minutes/day and 5 days/week for 8 weeks, n = 8) rats. The MAPs of all aged groups, SE-Aged, IM-Aged, and ET-Aged, were significantly higher than that of the SE-Young group. The regional cerebral blood flow (rCBF) in the SE-Aged and IM-Aged was significantly decreased as compared to SE-Young groups. However, rCBF of ET-Aged group was significantly higher than that in the IM-Aged group (P < 0.05). Moreover, the percentage of capillary vascularity (%CV) and the levels of VEGF and eNOS in the ET-Aged group were significantly increased compared to the IM-Aged group (P < 0.05). These results imply that exercise training could improve age-induced microvascular changes and hypoperfusion closely associated with the upregulation of VEGF and eNOS.
    BioMed research international. 01/2014; 2014:230791.

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