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Frontiers of Neurology and Neuroscience 2016Within the intracranial vasculature, atherosclerosis occurs in two distinctive patterns: (1) in Western populations who have severe extracranial and systemic... (Review)
Review
Within the intracranial vasculature, atherosclerosis occurs in two distinctive patterns: (1) in Western populations who have severe extracranial and systemic atherosclerosis, the severity of intracranial involvement is consistently less than that within extracranial arteries; and (2) in Asians, Africans, and Hispanics, who often have isolated intracranial arterial disease that is found to be more often accompanied by brain infarction than comparable extracranial atherosclerotic disease. Compared to coronary and extracranial carotid atherosclerosis, intracranial atherosclerosis has distinct pathological characteristics compared to that of extracranial arteries. Intracranial atherosclerosis (ICAS) had been understudied due to the relative inaccessibility of cerebral artery specimens under current treatment strategies. Acquiring post-mortem cerebral vessel specimens for histology processing is the most direct method to analyze the pathological characteristics of ICAS, in order to analyze both lumen stenosis and plaque components contributing to brain infarctions. The developments in high resolution magnetic resonance imaging (HRMRI) make it feasible to assess human ICAS in vivo. It is nevertheless challenging to understand vessel wall changes within brain vasculature demonstrated on HRMRI, as well as to identify biomarkers for stroke risk stratification and treatment strategy modification. Knowledge about intracranial atherosclerosis remains limited due to lack of human arterial specimens, and the development of proper animal models of human cerebral atherosclerosis is necessary to explore the pathogenesis of intracranial atherosclerosis and to assess various strategies preventing or treating ICAS-related stroke.
Topics: Cerebral Arteries; Humans; Intracranial Arteriosclerosis
PubMed: 27960191
DOI: 10.1159/000448267 -
Turkish Neurosurgery 2017The middle cerebral artery (MCA) covers a large part of the cerebral hemispheres and is therefore exposed during surgical intervention in this area. Aspects of cerebral... (Review)
Review
The middle cerebral artery (MCA) covers a large part of the cerebral hemispheres and is therefore exposed during surgical intervention in this area. Aspects of cerebral branches tend to vary, different branching patterns can be described, and several anomalies can be observed. Knowledge of these variations and anomalies is important and can be helpful to neurosurgeons and clinicians. The aim of this manuscript was to review the available literature on the cortical branches, branching pattern and anomalies of the MCA, to identify the gaps in the literature, and to fill these gaps by including the results of a pilot study. Twenty hemispheres were perfused with colored silicone and the MCA was dissected. For the cortical branches, the diameter, length, presence, duplication and origins were noted. Most commonly duplicated was the anterior parietal artery in 30.0%, and most commonly absent was the common temporal artery in 65.0%. A detailed description on the origins is given. Criteria were described for the bifurcation subtypes and medial bifurcation (50.0%) was most commonly observed. No anomalies were observed. Aspects previously neglected of the MCA cortical branches were reported in the pilot study. The branching subtypes were identified and criteria are given. Illustrations of the different branching subtypes and anomalies are provided. Certain aspects of the MCA anatomy have been neglected, and future studies should give adequate descriptions of the MCA cortical branches, MCA branching pattern, and any anomalies observed.
Topics: Humans; Middle Cerebral Artery; Temporal Arteries
PubMed: 27593841
DOI: 10.5137/1019-5149.JTN.18127-16.1 -
Experimental Animals Aug 2022Cerebral artery structure has not been extensively studied in primates. The aim of this study was to examine the cerebrovascular anatomy of cynomolgus monkeys (Macaca...
Cerebral artery structure has not been extensively studied in primates. The aim of this study was to examine the cerebrovascular anatomy of cynomolgus monkeys (Macaca fascicularis), which are one of the most commonly used primates in medical research on human diseases, such as cerebral infarction and subarachnoid hemorrhage. In this study, we investigated the anatomy and diameter of cerebral arteries from 48 cynomolgus monkey brain specimens. We found three anatomical differences in the vascular structure of this species compared to that in humans. First, the distal anterior cerebral artery is single. Second, the pattern in which both the anterior inferior cerebellar artery and posterior inferior cerebellar artery branch from the basilar artery is the most common. Third, the basilar artery has the largest diameter among the major arteries. We expect that this anatomical information will aid in furthering research on cerebrovascular disease using cynomolgus monkeys.
Topics: Animals; Brain; Cerebral Arteries; Humans; Macaca fascicularis
PubMed: 35444076
DOI: 10.1538/expanim.22-0002 -
Turkish Neurosurgery 2016The anterior cerebral artery (ACA) varies considerably and this complicates the description of the normal anatomy. The segmentation of the ACA is mostly agreed on by... (Review)
Review
The anterior cerebral artery (ACA) varies considerably and this complicates the description of the normal anatomy. The segmentation of the ACA is mostly agreed on by different authors, although the relationship of the pericallosal and callosomarginal arteries (CmA) is not agreed upon. The two basic configurations of the ACA are determined by the presence or absence of the CmA. The diameter, length and origin of the cortical branches have been measured and described by various authors and display great variability. Common anomalies of the ACA include the azygos, bihemispheric, and median anterior cerebral arteries. A pilot study was done on 19 hemispheres to assess the variation of the branches of the ACA. The most common variations included absence and duplication. The inferior internal parietal artery and the CmA were most commonly absent and the paracentral lobule artery was the most frequently duplicated (36.8%). The inferior internal parietal artery originated from the posterior cerebral artery in 40.0% and this was the most unusual origin observed. It is important to be aware of the possibility of variations since these variations can have serious clinical implications. The knowledge of these variations can be helpful to clinicians and neurosurgeons. The aim of this article is to review the anatomy and variations of the anterior cerebral artery, as described in the literature. This was also compared to the results from a pilot study.
Topics: Anterior Cerebral Artery; Cerebral Cortex; Humans; Pilot Projects
PubMed: 27337235
DOI: 10.5137/1019-5149.JTN.14294-15.1 -
International Journal of Environmental... May 2019Prenatal alcohol exposure results in an array of developmental abnormalities known as fetal alcohol spectrum disorders (FASDs). Despite the high prevalence of FASDs,... (Review)
Review
Prenatal alcohol exposure results in an array of developmental abnormalities known as fetal alcohol spectrum disorders (FASDs). Despite the high prevalence of FASDs, therapeutic interventions against accidental or intended exposure of developing fetuses to alcohol are limited. This review outlines current knowledge about mitochondria in cerebral blood vessels as a potential target for anti-FASDs intervention. First, it describes the multifaceted role of mitochondria in maintaining the cerebral artery diameter as shown in adult tissue. Second, current literature on alcohol-driven damage of mitochondrial morphology and function in several fetal tissues, including liver, heart, and brain is summarized. The functional consequences of alcohol exposure in these organs include morphological enlargement of mitochondria, increased oxidative stress, and alteration of cellular respiration. These studies point to a tissue-specific effect of alcohol on mitochondrial function and a particular vulnerability of fetal mitochondria to alcohol exposure when compared to adult counterparts. Third, recent work from our group describing persistent changes in fetal baboon cerebral artery proteome following three episodes of prenatal alcohol exposure is reviewed. In conclusion, the consequences of prenatal alcohol exposure on cerebral artery mitochondria constitute an open field of investigation and, eventually, a point of therapeutic intervention against FASDs.
Topics: Animals; Cerebral Arteries; Ethanol; Female; Fetal Alcohol Spectrum Disorders; Fetal Development; Fetus; Humans; Maternal-Fetal Exchange; Mitochondria; Pregnancy
PubMed: 31067632
DOI: 10.3390/ijerph16091586 -
Statistical modeling and knowledge-based segmentation of cerebral artery based on TOF-MRA and MR-T1.Computer Methods and Programs in... Apr 2020For cerebrovascular segmentation from time-of-flight (TOF) magnetic resonance angiography (MRA), the focused issues are segmentation accuracy, vascular network coverage...
BACKGROUND AND OBJECTIVE
For cerebrovascular segmentation from time-of-flight (TOF) magnetic resonance angiography (MRA), the focused issues are segmentation accuracy, vascular network coverage ratio, and cerebral artery and vein (CA/CV) separation. Therefore, cerebral artery segmentation is a challenging work, while a complete solution is lacking so far.
METHODS
The preprocessing of skull-stripping and Hessian-based feature extraction is first implemented to acquire an indirect prior knowledge of vascular distribution and shape. Then, a novel intensity- and shape-based Markov statistical modeling is proposed for complete cerebrovascular segmentation, where our low-level process employs a Gaussian mixture model to fit the intensity histogram of the skull-stripped TOF-MRA data, while our high-level process employs the vascular shape prior to construct the energy function. To regularize the individual data processes, Markov regularization parameter is automatically estimated by using a machine-learning algorithm. Further, cerebral artery and vein (CA/CV) separation is explored with a series of morphological logic operations, which are based on a direct priori knowledge on the relationship of arteriovenous topology and brain tissues in between TOF-MRA and MR-T1.
RESULTS
We employed 109 sets of public datasets from MIDAS for qualitative and quantitative assessment. The Dice similarity coefficient, false negative rate (FNR), and false positive rate (FPR) of 0.933, 0.158, and 0.091% on average, as well as CA/CV separation results with the agreement, FNR, and FPR of 0.976, 0.041, and 0.022 on average. For clinical visual assessment, our methods can segment various sizes of the vessel in different contrast region, especially performs better on vessels of small size in low contrast region.
CONCLUSION
Our methods obtained satisfying results in visual and quantitative evaluation. The proposed method is capable of accurate cerebrovascular segmentation and efficient CA/CV separation. Further, it can stimulate valuable clinical applications on the computer-assisted cerebrovascular intervention according to the neurosurgeon's recommendation.
Topics: Algorithms; Cerebral Arteries; Humans; Image Interpretation, Computer-Assisted; Knowledge Bases; Magnetic Resonance Angiography; Models, Statistical
PubMed: 31751871
DOI: 10.1016/j.cmpb.2019.105110 -
Current Vascular Pharmacology May 2014The incidence of obesity in the population is increasing at an alarming rate, with this comes an increased risk of insulin resistance (IR). Obesity and IR increase an... (Review)
Review
The incidence of obesity in the population is increasing at an alarming rate, with this comes an increased risk of insulin resistance (IR). Obesity and IR increase an individual's risk of having a stroke and they have been linked to several forms of dementia. Stroke and dementia are associated with, or exacerbated by, reduced cerebral blood flow, which has recently been described in obese patients. In this review we will discuss the effects of obesity on cerebral artery function and structure. Regarding their function, we will focus on the endothelium and nitric oxide (NO) dependent dilation. NO dependent dilation is impaired in cerebral arteries from obese rats, and the majority of evidence suggests this is a result of increased oxidative stress. We will also describe the limited studies showing that inward cerebral artery remodeling occurs in models of obesity, and that the remodeling is associated with an increase in the damage caused by cerebral ischemia. We will also discuss some of the more paradoxical findings associated with stroke and obesity, including the evidence that obesity is a positive factor for stroke survival. Finally we will discuss the evidence that links these changes in vascular structure and function to cognitive decline and dementia.
Topics: Animals; Cerebral Arteries; Cognition Disorders; Dementia; Disease Models, Animal; Endothelium, Vascular; Humans; Insulin Resistance; Obesity; Oxidative Stress; Potassium Channels; Stroke; Vasodilation
PubMed: 24846235
DOI: 10.2174/1570161112666140423222411 -
American Journal of Physiology. Heart... Jun 2013Maintenance of brain function depends on a constant blood supply. Deficits in cerebral blood flow are linked to cognitive decline, and they have detrimental effects on... (Review)
Review
Maintenance of brain function depends on a constant blood supply. Deficits in cerebral blood flow are linked to cognitive decline, and they have detrimental effects on the outcome of ischemia. Hypertension causes alterations in cerebral artery structure and function that can impair blood flow, particularly during an ischemic insult or during periods of low arterial pressure. This review will focus on the historical discoveries, novel developments, and knowledge gaps in 1) hypertensive cerebral artery remodeling, 2) vascular function with emphasis on myogenic reactivity and endothelium-dependent dilation, and 3) blood-brain barrier function. Hypertensive artery remodeling results in reduction in the lumen diameter and an increase in the wall-to-lumen ratio in most cerebral arteries; this is linked to reduced blood flow postischemia and increased ischemic damage. Many factors that are increased in hypertension stimulate remodeling; these include the renin-angiotensin-aldosterone system and reactive oxygen species levels. Endothelial function, vital for endothelium-mediated dilation and regulation of myogenic reactivity, is impaired in hypertension. This is a consequence of alterations in vasodilator mechanisms involving nitric oxide, epoxyeicosatrienoic acids, and ion channels, including calcium-activated potassium channels and transient receptor potential vanilloid channel 4. Hypertension causes blood-brain barrier breakdown by mechanisms involving inflammation, oxidative stress, and vasoactive circulating molecules. This exposes neurons to cytotoxic molecules, leading to neuronal loss, cognitive decline, and impaired recovery from ischemia. As the population ages and the incidence of hypertension, stroke, and dementia increases, it is imperative that we gain a better understanding of the control of cerebral artery function in health and disease.
Topics: Animals; Cerebral Arteries; Cerebrovascular Circulation; Humans; Hypertension; Renin-Angiotensin System; Vasoconstriction
PubMed: 23585139
DOI: 10.1152/ajpheart.00490.2012 -
Journal of Applied Physiology... Jun 2021The integrated responses regulating cerebral blood flow are understudied in women, particularly in relation to potential regional differences. In this study, we compared...
The integrated responses regulating cerebral blood flow are understudied in women, particularly in relation to potential regional differences. In this study, we compared dynamic cerebral autoregulation (dCA) and cerebrovascular reactivity to carbon dioxide (CVRco) in the middle (MCA) and posterior cerebral arteries (PCA) in 11 young endurance-trained women (age, 25 ± 4 yr; maximal oxygen uptake, 48.1 ± 4.1 mL·kg·min). dCA was characterized using a multimodal approach including a sit-to-stand and a transfer function analysis (TFA) of forced blood pressure oscillations (repeated squat-stands executed at 0.05 Hz and 0.10 Hz). The hyperoxic rebreathing test was utilized to characterize CVRco. Upon standing, the percent reduction in blood velocity per percent reduction in mean arterial pressure during initial orthostatic stress (0-15 s after sit-to-stand), the onset of the regulatory response, and the rate of regulation did not differ between MCA and PCA (all > 0.05). There was an ANOVA effect of anatomical location for TFA gain ( < 0.001) and a frequency effect for TFA phase ( < 0.001). However, normalized gain was not different between arteries ( = 0.18). Absolute CVRco was not different between MCA and PCA (1.55 ± 0.81 vs. 1.30 ± 0.49 cm·s/Torr, = 0.26). Relative CVRco was 39% lower in the MCA (2.16 ± 1.02 vs. 3.00 ± 1.09%/Torr, < 0.01). These findings indicate that the cerebral pressure-flow relationship appears to be similar between the MCA and the PCA in young endurance-trained women. The absence of regional differences in absolute CVRco could be women specific, although a direct comparison with a group of men will be necessary to address that issue. Herein, we describe responses from two major mechanisms regulating cerebral blood flow with a special attention on regional differences in young endurance-trained women. The novel findings are that dynamic cerebral autoregulation and absolute cerebrovascular reactivity to carbon dioxide appear similar between the middle and posterior cerebral arteries of these young women.
Topics: Adult; Blood Flow Velocity; Blood Pressure; Carbon Dioxide; Cerebrovascular Circulation; Female; Homeostasis; Humans; Male; Middle Cerebral Artery; Posterior Cerebral Artery; Young Adult
PubMed: 33955257
DOI: 10.1152/japplphysiol.00963.2020 -
Stroke Oct 2021The anatomic distribution of the deep cerebral perforators is considered either a given or subject to enormous variability. Most published overviews on this topic only... (Review)
Review
The anatomic distribution of the deep cerebral perforators is considered either a given or subject to enormous variability. Most published overviews on this topic only report findings from a limited number of anatomic dissections, and no attempt has been made to date to provide a comprehensive overview of all published data. A comprehensive literature search was performed on MEDLINE, Embase, and Google Scholar with the help of an information specialist. Three types of studies were included: (1) articles that described the anatomy and distribution territories of perforator groups arising from the arteries of the circle of Willis; (2) studies that evaluated the anatomy of the deep cerebral perforators using imaging techniques; and (3) studies that evaluated either microsurgically or radiologically confirmed perforator occlusion and reported the (magnetic resonance imaging-confirmed) distribution territory of the infarction together with a description of the clinical symptoms associated as a result of the infarction. A total of 2715 articles were screened and 53 were included. Of these, 40 dealt with the anatomic and imaging anatomy of perforator groups (37 reported results of dissections and 3 results of imaging studies), with a total of 2421 hemispheres investigated. Another 13 articles with 680 patients were included that evaluated perforator infarction territories. The deep cerebral perforator distribution shows large variability with poor concordance rates among reported studies, with the exception of the posterior communicating and anterior choroidal artery perforators. Despite the assumption that cerebral perforator anatomy is a given, studies show large variability in the anatomic distribution of various perforator groups. Perforator anatomy and relationships between perforator groups, as well as potential collateral circulation in these territories should be prioritized as a research topic in cerebrovascular disease in the near future.
Topics: Animals; Arterial Occlusive Diseases; Carotid Artery, Internal; Cerebral Arteries; Cerebrovascular Circulation; Collateral Circulation; Humans; Magnetic Resonance Imaging
PubMed: 34311568
DOI: 10.1161/STROKEAHA.120.034096