Physiology and Clinical Relevance of Enlarged Perivascular Spaces in the Aging Brain

Neurology ◽  
2021 ◽  
pp. 10.1212/WNL.0000000000013077
Author(s):  
Corey W Bown ◽  
Roxana O Carare ◽  
Matthew S Schrag ◽  
Angela L Jefferson

Perivascular spaces (PVS) are fluid filled compartments that are part of the cerebral blood vessel wall and represent the conduit for fluid transport in and out of the brain. PVS are considered pathologic when sufficiently enlarged to be visible on magnetic resonance imaging. Recent studies have demonstrated that enlarged PVS (ePVS) may have clinical consequences related to cognition. Emerging literature points to arterial stiffening and abnormal protein aggregation in vessel walls as two possible mechanisms that drive ePVS formation. In this review, we describe the clinical consequences, anatomy, fluid dynamics, physiology, risk factors, and in vivo quantification methods of ePVS. Given competing views of PVS physiology, we detail the two most prominent theoretical views and review ePVS associations with other common small vessel disease markers. As ePVS are a marker of small vessel disease and ePVS burden is higher in Alzheimer’s disease, a comprehensive understanding about ePVS is essential in developing prevention and treatment strategies.

2015 ◽  
Vol 36 (1) ◽  
pp. 72-94 ◽  
Author(s):  
Anna Poggesi ◽  
Marco Pasi ◽  
Francesca Pescini ◽  
Leonardo Pantoni ◽  
Domenico Inzitari

The term cerebral small vessel disease (SVD) refers to a group of pathologic processes with various etiologies that affect small arteries, arterioles, venules, and capillaries of the brain. Magnetic resonance imaging (MRI) correlates of SVD are lacunes, recent small subcortical infarcts, white-matter hyperintensities, enlarged perivascular spaces, microbleeds, and brain atrophy. Endothelial dysfunction is thought to have a role in the mechanisms leading to SVD-related brain changes, and the study of endothelial dysfunction has been proposed as an important step for a better comprehension of cerebral SVD. Among available methods to assess endothelial function in vivo, measurement of molecules of endothelial origin in peripheral blood is currently receiving selective attention. These molecules include products of endothelial cells that change when the endothelium is activated, as well as molecules that reflect endothelial damage and repair. This review examines the main molecular factors involved in both endothelial function and dysfunction, and the evidence linking endothelial dysfunction with cerebral SVD, and gives an overview of clinical studies that have investigated the possible association between endothelial circulating biomarkers and SVD-related brain changes.


Biomolecules ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 994
Author(s):  
Natasha Ting Lee ◽  
Lin Kooi Ong ◽  
Prajwal Gyawali ◽  
Che Mohd Nasril Che Mohd Nassir ◽  
Muzaimi Mustapha ◽  
...  

The cerebral endothelium is an active interface between blood and the central nervous system. In addition to being a physical barrier between the blood and the brain, the endothelium also actively regulates metabolic homeostasis, vascular tone and permeability, coagulation, and movement of immune cells. Being part of the blood–brain barrier, endothelial cells of the brain have specialized morphology, physiology, and phenotypes due to their unique microenvironment. Known cardiovascular risk factors facilitate cerebral endothelial dysfunction, leading to impaired vasodilation, an aggravated inflammatory response, as well as increased oxidative stress and vascular proliferation. This culminates in the thrombo-inflammatory response, an underlying cause of ischemic stroke and cerebral small vessel disease (CSVD). These events are further exacerbated when blood flow is returned to the brain after a period of ischemia, a phenomenon termed ischemia-reperfusion injury. Purinergic signaling is an endogenous molecular pathway in which the enzymes CD39 and CD73 catabolize extracellular adenosine triphosphate (eATP) to adenosine. After ischemia and CSVD, eATP is released from dying neurons as a damage molecule, triggering thrombosis and inflammation. In contrast, adenosine is anti-thrombotic, protects against oxidative stress, and suppresses the immune response. Evidently, therapies that promote adenosine generation or boost CD39 activity at the site of endothelial injury have promising benefits in the context of atherothrombotic stroke and can be extended to current CSVD known pathomechanisms. Here, we have reviewed the rationale and benefits of CD39 and CD39 therapies to treat endothelial dysfunction in the brain.


Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Dorothee Schoemaker ◽  
Yesica Zuluaga ◽  
Lina Velilla ◽  
Carolina Ospina ◽  
Francisco Lopera ◽  
...  

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a hereditary cerebral small vessel disease (cSVD) linked to NOTCH3 mutations and leading to the early onset of stroke and vascular cognitive impairment. Neuroimaging features of CADASIL include extensive white matter hyperintensity, lacunes, cerebral microbleeds and enlarged perivascular spaces. Researchers from the Rotterdam study recently proposed a MRI-based cSVD Score reflecting the overall burden of cerebrovascular injury (Yilmaz et al., 2018). Here, we explored the relevance of this cSVD Score in distinguishing CADASIL subjects from non-carriers and its relationships to cognition. We evaluated 26 NOTCH3 mutation carriers and 25 non-carriers from large Colombian families. Of the CADASIL subjects, 4 had previous strokes (symptomatic) and 22 had no history of strokes (asymptomatic). All subjects underwent a 3T MRI and a neuropsychological evaluation. Structural MRI markers of cSVD, as well as the cSVD Score, were quantified in each subject following established protocols. Demographic, cognitive and neuroimaging features across groups are presented in Table 1. The cSVD Score significantly differed between groups, after adjusting for age (Figure 1-A). In CADASIL subjects, the cSVD Score was negatively related to performance in Memory, Processing Speed, Executive Function, after accounting for age and education (Figure 1-B). These results suggest that the cSVD Score could be a useful marker of disease severity in CADASIL. Longitudinal studies are now needed to determine if this score allows predicting clinical outcomes in CADASIL, such as stroke or dementia.


2010 ◽  
Vol 23 (9) ◽  
pp. 933-933
Author(s):  
K. Kohara ◽  
N. Ochi ◽  
Y. Tabara ◽  
T. Miki

Nosotchu ◽  
1996 ◽  
Vol 18 (1) ◽  
pp. 10-18
Author(s):  
Tatsuo Kohriyama ◽  
Shinya Yamaguchi ◽  
Eiji Tanaka ◽  
Yasuhiro Yamamura ◽  
Shigenobu Nakamura

2021 ◽  
Vol 12 ◽  
Author(s):  
Yangyi Fan ◽  
Yicheng Xu ◽  
Ming Shen ◽  
Huailian Guo ◽  
Zhaoxu Zhang

Objectives: The main markers of cerebral small vessel disease (cSVD) on MRI may be entered into a scoring system, with the total score representing the overall burden of cSVD. An association between total cSVD score and cognitive dysfunction has been reported in several cohorts. The present study aimed to investigate this association in outpatients with amnestic disorders.Materials and Methods: Outpatients with amnestic complaints in a memory clinic (n = 289) were recruited retrospectively. All the patients had undergone clinical and cognitive evaluation at first presentation. Cognitive function was assessed by Montreal Cognitive Assessment (MoCA) scale. The total cSVD score was based on the following markers on MRI: lacune; white matter hyperintensities, microbleed, and enlarged perivascular spaces. The association between total cSVD score and MoCA score was tested via Spearman's analysis and a linear regression model.Results: Among the 289 patients, rates for 0–4 cSVD markers respectively ranged from 30.4 to 2.8%. A multiple linear regression model revealed an inverse correlation between the total cSVD score and MoCA score. The association remained significant after adjusting for gender, age, education, levels of medial temporal lobe atrophy, and classical vascular risk factors [β = −0.729, 95% CI (−1.244, −0.213); P = 0.006]. When individual markers were individually analyzed after adjusting for the same factors, only microbleed associated with MoCA score [β = −3.007, 95% CI (−4.533, −1.480), P < 0.001].Conclusions: A significant association was demonstrated between total cSVD score and cognitive performance in the outpatients with amnestic disorders.


Stroke ◽  
2010 ◽  
Vol 41 (3) ◽  
pp. 450-454 ◽  
Author(s):  
Fergus N. Doubal ◽  
Alasdair M.J. MacLullich ◽  
Karen J. Ferguson ◽  
Martin S. Dennis ◽  
Joanna M. Wardlaw

2015 ◽  
Vol 112 (7) ◽  
pp. E796-E805 ◽  
Author(s):  
Fabrice Dabertrand ◽  
Christel Krøigaard ◽  
Adrian D. Bonev ◽  
Emmanuel Cognat ◽  
Thomas Dalsgaard ◽  
...  

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), caused by dominant mutations in the NOTCH3 receptor in vascular smooth muscle, is a genetic paradigm of small vessel disease (SVD) of the brain. Recent studies using transgenic (Tg)Notch3R169C mice, a genetic model of CADASIL, revealed functional defects in cerebral (pial) arteries on the surface of the brain at an early stage of disease progression. Here, using parenchymal arterioles (PAs) from within the brain, we determined the molecular mechanism underlying the early functional deficits associated with this Notch3 mutation. At physiological pressure (40 mmHg), smooth muscle membrane potential depolarization and constriction to pressure (myogenic tone) were blunted in PAs from TgNotch3R169C mice. This effect was associated with an ∼60% increase in the number of voltage-gated potassium (KV) channels, which oppose pressure-induced depolarization. Inhibition of KV1 channels with 4-aminopyridine (4-AP) or treatment with the epidermal growth factor receptor agonist heparin-binding EGF (HB-EGF), which promotes KV1 channel endocytosis, reduced KV current density and restored myogenic responses in PAs from TgNotch3R169C mice, whereas pharmacological inhibition of other major vasodilatory influences had no effect. KV1 currents and myogenic responses were similarly altered in pial arteries from TgNotch3R169C mice, but not in mesenteric arteries. Interestingly, HB-EGF had no effect on mesenteric arteries, suggesting a possible mechanistic basis for the exclusive cerebrovascular manifestation of CADASIL. Collectively, our results indicate that increasing the number of KV1 channels in cerebral smooth muscle produces a mutant vascular phenotype akin to a channelopathy in a genetic model of SVD.


Stroke ◽  
2018 ◽  
Vol 49 (5) ◽  
pp. 1279-1281 ◽  
Author(s):  
Iolanda Riba-Llena ◽  
Joan Jiménez-Balado ◽  
Xavier Castañé ◽  
Anna Girona ◽  
Antonio López-Rueda ◽  
...  

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