Abstract TP481: Deep and Superficial Brain Arteries Flow Pattern Suggest Differential Risks to Systemic Hemodynamics

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Jose Gutierrez ◽  
Pablo J Blanco ◽  
J David Spence
Keyword(s):  
Chronic Hypertension ◽  
Large Artery ◽  
Systemic Hemodynamic ◽  
Lenticulostriate Arteries ◽  
Brain Arteries ◽  
Pressure Peak ◽  
Basilar Arteries ◽  
Posterior Parietal ◽  
Systemic Arteries ◽  
The Brain

Introduction: Penetrating arteries supplying the basal ganglia and the brain stem are often affected by chronic hypertension whereas distal branching arteries supplying the brain convexity and corona radiata may be injured by hypoperfusion. We hypothesized that under equal systemic flow dynamics, distal branching brain arteries will have a lower pressure peak than penetrating arteries. Methods: We used an Anatomically Detailed Arterial Network (ADAN) model to predict pressure waveforms for brain and systemic arteries. The anatomical details were obtained from published literature and match for an average man, height of 170 cms and body surface area of 1.65 m2. Arterial length and radius were obtained from published literature for each organ. Standard governing equations for the flow of an incompressible fluid in compliant pipes are considered in each arterial segment. Proper coupling conditions at junctions are also postulated, as well as terminal Windkessel models. Results: Compared to systemic arteries, brain arteries have an early peak in flow and pressure, followed by a gradual decline in flow and pressure over time (figure 1). The posterior parietal artery has the lowest MAP and pulse pressure of the four brain arteries tested, even if the pulsatility and resistance indices remained relatively the same. Consequently, the pressure pulse peak for the posterior parietal artery hovers around 80 mmhg compared with approximately 110 mmHg for the lenticulostriate arteries and the middle cerebral and basilar arteries. Lenticulostriate arteries had similar hemodynamic profiles to the large artery branches of the circle of Willis. Conclusion: Penetrating brain arteries are susceptible to high pressure remodeling because of their immediate branching from a large artery, while distal cortical arteries are more susceptible to hypoperfusion. These regional susceptibilities to systemic hemodynamic may influence brain health and contribute to neurodegeneration.

Vasomotion of basilar arteries in vivo

1990 ◽  
Vol 258 (6) ◽  
pp. H1829-H1834 ◽  
Author(s):  
K. Fujii ◽  
D. D. Heistad ◽  
F. M. Faraci
Keyword(s):  
Moderate Hypertension ◽  
Vessel Diameter ◽  
Base Line ◽  
Large Artery ◽  
Cranial Window ◽  
Basilar Arteries ◽  
The Mean ◽  
Rhythmic Change ◽  
The Brain

Vasomotion is a rhythmic change in vascular caliber that has been described in vivo mainly in peripheral arterioles. In this study, we have characterized vasomotion in a large artery of the brain in vivo. In anesthetized rats, spontaneous vasomotion was observed in 38 of 47 basilar arteries visualized through a cranial window. Base-line arterial diameter was 259 +/- 9 (means +/- SE) microns. Under control conditions, the frequency of vasomotion was 4.8 +/- 0.2 cycles/min, and the amplitude was 19 +/- 2% of the mean diameter. Vasomotion usually occurred simultaneously along the entire length of the vessel, but in some arteries it propagated in either direction. Moderate hypertension (phenylephrine) or vasoconstriction induced by topical application of serotonin, vasopressin, or the thromboxane analogue U 46619 increased the frequency of vasomotion. Moderate hypotension or vasodilation induced by nitroglycerin, adenosine, or acetylcholine decreased the frequency. Marked hypertension, hypotension, or vasodilatation abolished vasomotion. Thus vasomotion of the basilar artery in vivo 1) is common and of relatively large amplitude, 2) does not seem to be driven by a single pacemaker, and 3) is dependent on vessel diameter or vasomotor tone.

scholarly journals Giant brain aneurysm in a two–year–old girl

2010 ◽  
Vol 50 (4) ◽  
pp. 252
Author(s):  
Prastiya Indra G ◽  
Hapsari Kusumawardani ◽  
Darto Saharso
Keyword(s):  
Cerebral Artery ◽  
Hemorrhagic Stroke ◽  
Giant Aneurysm ◽  
Posterior Circulation ◽  
Anterior Communicating Artery ◽  
Brain Aneurysm ◽  
Brain Arteries ◽  
High Incidence ◽  
Basilar Arteries ◽  
The Brain

Brain aneurysm is an abnormal outward bulging of one of the brain arteries. Brain aneurysms are often discovered when they rupture, causing bleeding into the brain or the space surrounding the brain called the subarachnoid space. This subarachnoid hemorrhage can lead to hemorrhagic stroke, brain damage and death.1The aneurysm can present in all ages, but mainly after 50 year of age (ages 35 – 60), and exists a greater predisposition in females, with a ratio 3:2.2 Intracranial aneurysms in children are rare. About 0.5-4.6% of all aneurysms in children distinctly differ from adult, especially in male (2:1 to 3:1).3,4,5,6These injuries are located mainly in any cerebral artery specifically in those related to the well-known Circles of Willis such as internal carotid, middle cerebral and anterior cerebral artery as well as anterior communicating artery that corresponds to anterior circulatory circuit. In the posterior region they can be observed above the posterior cerebral artery, vertebral and basilar arteries, mainly. Aneurysm in children is mostly located at the bifurcation of ICA or vertebra-basilar artery posterior circulation, yet disproportionately with high incidence of posterior circulation aneurysm (40-50%) and of giant aneurysm (30-45%)

Microvascular features that suggest effectors of blood-flow regulation in the brain: Evidence by SEM of corrosion casts of intracerebral vessels

1990 ◽  
Vol 48 (3) ◽  
pp. 274-275
Author(s):  
Enrico D.F. Motti ◽  
Hans-Georg Imhof ◽  
Gazi M. Yasargil
Keyword(s):  
Blood Flow ◽  
Perfusion Pressure ◽  
Corrosion Casts ◽  
Cerebral Microcirculation ◽  
Pial Arteries ◽  
Random Occurrence ◽  
Brain Arteries ◽  
Homogeneous Network ◽  
The Brain

Physiologists have devoted most attention in the cerebrovascular tree to the arterial side of the circulation which has been subdivided in three levels: 1) major brain arteries which keep microcirculation constant despite changes in perfusion pressure; 2) pial arteries supposed to be effectors regulating microcirculation; 3) intracerebral arteries supposed to be deprived of active cerebral blood flow regulating devices.The morphological search for microvascular effectors in the cerebrovascular bed has been elusive. The opaque substance of the brain confines in vivo investigation to the superficial pial arteries. Most morphologists had to limit their observation to the random occurrence of a favorable site in the practically two-dimensional thickness of diaphanized histological sections. It is then not surprising most investigators of the cerebral microcirculation refer to an homogeneous network of microvessels interposed between arterioles and venules.We have taken advantage of the excellent depth of focus afforded by the scanning electron microscope (SEM) to investigate corrosion casts obtained injecting a range of experimental animals with a modified Batson's acrylic mixture.

scholarly journals The Modular Organization of Pain Brain Networks: An fMRI Graph Analysis Informed by Intracranial EEG

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Camille Fauchon ◽  
David Meunier ◽  
Isabelle Faillenot ◽  
Florence B Pomares ◽  
Hélène Bastuji ◽  
...  
Keyword(s):  
Information Integration ◽  
Functional Organization ◽  
Brain Connectivity ◽  
Brain Networks ◽  
Modular Organization ◽  
Noxious Heat ◽  
Intracranial Eeg ◽  
Brain Connectome ◽  
Posterior Parietal ◽  
The Brain

Abstract Intracranial EEG (iEEG) studies have suggested that the conscious perception of pain builds up from successive contributions of brain networks in less than 1 s. However, the functional organization of cortico-subcortical connections at the multisecond time scale, and its accordance with iEEG models, remains unknown. Here, we used graph theory with modular analysis of fMRI data from 60 healthy participants experiencing noxious heat stimuli, of whom 36 also received audio stimulation. Brain connectivity during pain was organized in four modules matching those identified through iEEG, namely: 1) sensorimotor (SM), 2) medial fronto-cingulo-parietal (default mode-like), 3) posterior parietal-latero-frontal (central executive-like), and 4) amygdalo-hippocampal (limbic). Intrinsic overlaps existed between the pain and audio conditions in high-order areas, but also pain-specific higher small-worldness and connectivity within the sensorimotor module. Neocortical modules were interrelated via “connector hubs” in dorsolateral frontal, posterior parietal, and anterior insular cortices, the antero-insular connector being most predominant during pain. These findings provide a mechanistic picture of the brain networks architecture and support fractal-like similarities between the micro-and macrotemporal dynamics associated with pain. The anterior insula appears to play an essential role in information integration, possibly by determining priorities for the processing of information and subsequent entrance into other points of the brain connectome.

THE EFFECT OF AGE ON THE ELASTICITY OF THE MAJOR BRAIN ARTERIES

1965 ◽  
Vol 43 (2) ◽  
pp. 185-202 ◽  
Author(s):  
Douglas E. Busby ◽  
Alan C. Burton
Keyword(s):  
High Pressures ◽  
Mean Value ◽  
Collagen Fibers ◽  
Peripheral Arteries ◽  
Volume Data ◽  
Maximum Slope ◽  
Brain Arteries ◽  
Autopsy Specimens ◽  
Collagenous Fibers ◽  
The Brain

In previous work on peripheral arteries the law of Laplace has been applied to the pressure–volume data to yield the elastic constants and interrelation of function of elastin and collagenous fibers in the wall, and the changes with age. Similar analysis of major brain arteries has been made on autopsy specimens, aged 2 to 90. Volume (micrometer syringe) and pressure (electromanometer) in arterial segments were accurately measured. Absolute volumes were obtained by collapsing the artery with negative pressure, and the "unstretched circumferences" of the vessel were deduced from the curves. Tension–circumference curves were constructed. These showed the characteristic increasing slope (increased "elastance" or "stiffness") with increasing degree of stretch, interpreted as successive "recruitment" of collagen fibers as they reach their unstretched length.Increases in arterial length with distension were very small and negligible in vessels older than 30 years. Maximum slope (stiffness) was reached at pressures in the physiological range. The maximal stretch was 26 to 38% for vessels aged 30 to 90 years. This is less than for peripheral arteries, except those over 80 years old.Ageing showed itself mainly in reduction of the stretch required to bring 50% of the collagen fibers to their unstretched length, i.e. in the "degree of slackness". This was 30% stretch for younger vessels, 20% for the older. Unlike the peripheral arteries, the brain arteries show no significant increase with age in the maximal stiffness (related to their total collagen content). The mean value of the Young's modulus of the wall at high pressures was 1.93 ± 0.67 × 107 dynes/sq.cm. No significant change in thickness of the wall or lumen diameter with age was found.It is concluded that the major brain arteries are less distensible than peripheral arteries of comparable diameter, particularly in youth. Distensibility decreases with age, mainly because the "degree of slackness" of the collagen fibers is reduced. At physiological pressures the major resistance to distension is due to the collagen fibers rather than to the elastin fibers, which appear histologically to be less abundant, except in the elastica interna, than in peripheral arteries.

Abstract TMP82: Increased Intracerebral Hemorrhage During Acute and Chronic Hypertension in Alzheimer's Transgenic Mice

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
David H Cribbs ◽  
Giselle Passos ◽  
Vitaly Vasilevko
Keyword(s):  
Risk Factor ◽  
Transgenic Mice ◽  
Intracerebral Hemorrhage ◽  
Amyloid Precursor Protein ◽  
Significant Risk ◽  
Significant Risk Factor ◽  
Chronic Hypertension ◽  
Cerebrovascular System ◽  
The Brain ◽  
Tg2576 Mice

Hypertension is a major risk factor for intracerebral hemorrhage (ICH), and the accumulation of amyloid-beta (Aβ) in the cerebrovascular system, cerebral amyloid angiopathy (CAA), is also a significant risk factor for intracerebral hemorrhage ICH. Currently, there are no animal studies demonstrating a direct involvement of hypertension in the accumulation of Alzheimer’s disease-like pathology. To address this issue we have developed several mouse models that combine hypertension protocols with amyloid precursor protein (APP) transgenic mice (Tg2576), which accumulate significant CAA in the large cerebral vessels and the meninges by 18 months of age. The goal of this study was to determine the effect of acute and chronic hypertension on ICH in wildtype and a transgenic mouse model overexpressing a mutant human amyloid precursor protein (Tg2576 mice) associated with early onset AD and CAA. Fifteen-month-old Tg2576 mice and non-transgenic (nTg) littermates were treated with an angiotensin II (AngII) infusion (1000 ng/kg/min) and L-NAME (100 mg/kg/day) in drinking water to produce chronic hypertension. One week later, transient acute hypertension was induced by daily AngII injections (0.5 μg/g, s.c., twice daily) to produce ICH. A similar increase in mean blood pressure was observed in Tg2576 and nTg mice when evaluated 2 weeks after initiation of treatment. However Tg2576 mice had a higher incidence of signs of stroke compared with nTg littermates (P > 0.05). These data suggest that the accumulation of Aβ in the brain has an important role in development of ICH. Moreover, there was robust glial activation and increase in CAA in the gray matter of Tg2576 mice showing that hypertension may affect gray as well as white matter in the brain. Further studies may provide insights into the hypertension-induced changes in the cerebral vascular system that initiated the increase in CAA. The accumulation of Aβ in the cerebrovascular system is a significant risk factor for intracerebral hemorrhage (ICH), and has been linked to endothelial transport failure and blockage of perivascular drainage. While management of hypertension and atherosclerosis can reduce the incidence of ICH, there are currently no approved therapies for attenuating CAA.

scholarly journals Hypertension-Related Cerebral Microbleeds

2020 ◽  
Vol 12 (3) ◽  
pp. 266-269
Author(s):  
Sujan T. Reddy ◽  
Sean I. Savitz
Keyword(s):  
Magnetic Resonance Imaging ◽  
Cerebral Microbleeds ◽  
Chronic Hypertension ◽  
Amyloid Angiopathy ◽  
Resonance Imaging ◽  
Gradient Echo ◽  
Cerebellar Hemorrhage ◽  
Common Causes ◽  
Cerebral Amyloid ◽  
The Brain

Hypertension and cerebral amyloid angiopathy are the most common causes of cerebral microbleeds. The pattern of microbleeds on T2*-weighted gradient echo sequence of magnetic resonance imaging of the brain can be indicative of the etiology of intracerebral hemorrhage. We describe a case of cerebellar hemorrhage with cerebral microbleeds secondary to chronic hypertension.

scholarly journals The arteries of the brain base in the degu (Octodon degus Molina 1782)

2014 ◽  
Vol 59 (No. 7) ◽  
pp. 343-348 ◽  
Author(s):  
W. Brudnicki ◽  
B. Skoczylas ◽  
R. Jablonski ◽  
W. Nowicki ◽  
A. Brudnicki ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Internal Carotid Artery ◽  
Basilar Artery ◽  
Internal Carotid ◽  
Cerebral Arteries ◽  
Left Vertebral Artery ◽  
Brain Arteries ◽  
Middle Cerebral Arteries ◽  
The Brain ◽  
Synthetic Latex

The brain arteries derived from 50 adult degu individuals of both sexes were injected with synthetic latex introduced with a syringe into the left ventricle of the heart under constant pressure. After fixation in 5% formalin and brain preparation, it was found that the sources of the brain’s supply of blood are vertebral arteries and the basilar artery formed as a result of their anastomosis. The basilar artery gave rise to caudal cerebellar arteries and then divided into two branches which formed the arterial circle of the brain. The internal carotid arteries in degus, except for one case, were heavily reduced and did not play an important role in the blood supply to the brain. The arterial circle of the brain in 48% of the cases was open from the rostral side. Variation was identified in the anatomy and the pattern of the arteries of the base of the brain in the degu which involved an asymmetry of the descent of caudal cerebellar arteries (6.0%), rostral cerebellar arteries (8%) as well as middle cerebral arteries (12%). In 6% of the individuals double middle cerebral arteries were found. In one out of 50 cases there was observed a reduction in the left vertebral artery and the appearance of the internal carotid artery on the same side. In that case the left part of the arterial circle of the brain was supplied with blood by an internal carotid artery, which was present only in that animal.

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