scholarly journals Average dimensions of the vessels at the base of the brain and the embryological basis of its variations

2013 ◽  
Vol 02 (04) ◽  
pp. 180-189
Author(s):  
Iqbal S.

Abstract Background and aims: The cerebral circulation is constantly maintained by the anastomotic circle of Willis which is often anomalous in more than 50% of the normal adult brains. These anomalies increase the risk of the stroke and transient ischemic attack in older patients. Adequate blood flow through the circle of Willis is often necessary to prevent these ischemic infarctions. The anomalies of cerebral vessels are directly related to the differential growth of various parts of the brain. A detailed knowledge of the individual measurements of the cerebral arteries is useful to neurosurgeon in planning the shunt operations and in the choice of their patients. The present study is aimed to analyze the average dimensions of the vessels at the base of brain and an attempt to explain the common form of variations in terms of embryological development. Materials and methods: Fifty adult cadaveric brains were obtained from routine cadaveric dissections. The base of the brain with the circle of Willis was fixed in 10% formalin and preserved. The circle was analyzed for variations in the size, length and number of the component vessels and any asymmetry in the configuration. The dimensions of the vessels forming the circle were measured using graduated calipers. The observations were recorded and tabulated. Results: Asymmetry was observed in 10% to 36% of the circles in this study. Anomalies were more common in the posterior than in the anterior part of the circle. The posterior anomalies included hypoplastic vessels, absent vessels and embryonic derivation while anterior anomalies were predominantly of accessory vessels. Middle cerebral artery exhibited the least variations. In majority of the circles, left sided vessels were larger in diameter than the right. Conclusions: Variations are more common in the posterior than in the anterior part of the circle and on the right than on the left side of the brain. There was no correlation between the variations of circle of Willis of the right side and the left cerebral dominance. There seems to be no difference between races, concerning the anatomic variations of the brain circulation.

2017 ◽  
Vol 4 (4) ◽  
pp. 1249 ◽  
Author(s):  
Ramanuj Singh ◽  
Ajay Babu Kannabathula ◽  
Himadri Sunam ◽  
Debajani Deka

Background: The circle of Willis (CW) is a vascular network formed at the base of skull in the interpeduncular fossa. Its anterior part is formed by the anterior cerebral artery, from either side. Anterior communicating artery connects the right and left anterior cerebral arteries. Posteriorly, the basilar artery divides into right and left posterior cerebral arteries and each join to ipsilateral internal carotid artery through a posterior communicating artery. Anterior communicating artery and posterior communicating arteries are important component of circle of Willis, acts as collateral channel to stabilize blood flow. In the present study, anatomical variations in the circle of Willis were noted.Methods: 75 apparently normal formalin fixed brain specimens were collected from human cadavers. 55 Normal anatomical pattern and 20 variations of circle of Willis were studied. The Circles of Willis arteries were then colored, photographed, numbered and the abnormalities, if any, were noted.Results: Twenty variations were noted. The most common variation observed is in the anterior communicating artery followed by some other variations like the Posterior communicating arteries, Anterior cerebral artery and posterior cerebral artery (PCA) was found in 20 specimens.Conclusions: Knowledge on of variations in the formation of Circle of Willis, all surgical interventions should be preceded by angiography. Awareness of these anatomical variations is important in the neurovascular procedures.


1974 ◽  
Vol 41 (1) ◽  
pp. 107-112
Author(s):  
Shigeaki Hori ◽  
Williamina A. Himwich

✓ A technique for exposing the vessels in the anterior part of the circle of Willis in the dog is described. Some of the physiological and anatomical characteristics of the anterior communicating and the anterior cerebral arteries are discussed.


2013 ◽  
Vol 02 (03) ◽  
pp. 122-127
Author(s):  
Bishwajeet Saikia ◽  
Kunjalal Talukdar ◽  
Joydev Sarma ◽  
Amitav Sarma ◽  
Sandeep Madaan

Abstract Background and aims: Stroke, the most frequent expression of cerebrovascular disease is one of the leading causes of death and disability throughout the world. The manifestations are largely accounted by the anatomical distribution of the stems and branches of the circle of Willis supplying the brain. Considerable individual variation exists in the pattern and caliber of the individual vessels forming the circle of Willis, which may possibly impair the collateral blood flow. The knowledge of these variations thus, becomes essential for medical as well as surgical interventions. There may possibly be some regional variations in the cerebral arteries not mentioned in standard available texts. Thus, the regional based study of variations present becomes essential. The present study aims to focus on the variation of one of such branches, the anterior cerebral artery (ACA) in the population of Assam, India. Material and Methods: The ACAs of 70 human cadaveric brains were examined by gross dissection in the department of Anatomy and Forensic medicine in Gauhati Medical College. Results: Hypoplastic A-1 segment were found in 7% cases, Hypoplastic A-2 segment in 2.85% cases, Buttonhole formation in 8.57% cases and aneurysmal dilatation in 1.42% cases. The results were compared with that of other authors and variations noted. Conclusion: The present study of ACA using gross dissection is an initial step in providing a reference to the healthcare professionals in the region of Assam. Based on this further studies using newer imaging methods should be carried out to correlate the manifestations clinically.


2021 ◽  
Vol 14 ◽  
Author(s):  
Dongya Wu ◽  
Xin Li ◽  
Jun Feng

Brain connectivity plays an important role in determining the brain region’s function. Previous researchers proposed that the brain region’s function is characterized by that region’s input and output connectivity profiles. Following this proposal, numerous studies have investigated the relationship between connectivity and function. However, this proposal only utilizes direct connectivity profiles and thus is deficient in explaining individual differences in the brain region’s function. To overcome this problem, we proposed that a brain region’s function is characterized by that region’s multi-hops connectivity profile. To test this proposal, we used multi-hops functional connectivity to predict the individual face activation of the right fusiform face area (rFFA) via a multi-layer graph neural network and showed that the prediction performance is essentially improved. Results also indicated that the two-layer graph neural network is the best in characterizing rFFA’s face activation and revealed a hierarchical network for the face processing of rFFA.


Author(s):  
Haris Kamal ◽  
Edward J. Fine ◽  
Banafsheh Shakibajahromi ◽  
Ashkan Mowla

This publication reviews the steps in the path towards obtaining a complete image of the brain. Up to the 1920s, plain X-ray films could demonstrate only calcified tumors, shifts in midline position of a calcified pineal gland due to a mass in the cranium, or foreign metallic objects within the skull. Walter Dandy reported in 1918 that he visualized cerebral ventricles by introducing air as a contrast agent through a trocar into one of the occipital lobes or the right frontal horn of the ventricular system. Dandy localized lesions that distorted or shifted the ventricles. In 1920, Dandy placed air by lumbar puncture into the spinal subarachnoid space that could visualize the brain and entire ventricles. Antonio Egas Moniz with the assistance of his neurosurgeon colleague, Almeida Lima, obtained X-ray images of cerebral arteries of dogs and decapitated human heads from corpses after injecting strontium bromide into their carotid arteries. Satisfied by these experiments, Moniz injected strontium bromide directly into carotid arteries of five patients which failed to show intracranial vessels. In the sixth patient, intracranial arteries were outlined but that patient died of cerebral thrombosis presumably due to the hyper- osmolality of that contrast agent. Finally, on June 18, 1927, Moniz injected 22% sodium iodine into a 20-year-old man and obtained clear visualization of his carotid artery and intracerebral branches after temporarily occluding the artery with a ligature. 


Author(s):  
Gururaj Itagi ◽  
Laveena D’Mello

Human senses are natural contributions which transform the information to the brain for further processing to understand what is being presented to an individual through sight, hearing, touch, smell, taste. Senses will also determine the understanding of the different concept being presented and recall those contents or information for the right situation for the right action. To help the individual learner, teachers in various educational institutions should understand and apply the Multi-Sensory Approach in presenting their teaching contents in a classroom teaching to reach out the uniqueness of the individual learner’s learning style and bring the best academic excellence. With the main aim of helping learners with their unique learning style, the “Itagi’s Model of Multi-Sensory Approach” is been developed by Gururaj Itagi. Highlighting various methods, strategies and techniques in teaching process focussing on individual learning style to maximize student’s academic excellence. This model is framed based on the different learning style of students. This framework considers integrated phases of teaching such as auditory, visual and kinaesthetic approach. The model focuses on Adolescence (aged 12-18 years) mainly on students with scholastic backwardness.


2020 ◽  
Vol 40 (4) ◽  
pp. 315-323
Author(s):  
Dayane Kelly Sabec-Pereira ◽  
Fabiano C. Lima ◽  
Fabiano R. Melo ◽  
Fabiana Cristina S.A. Melo ◽  
Kleber Fernando Pereira ◽  
...  

ABSTRACT: We studied the arterial circle in the brain of five specimens of the Alouatta belzebul primate. The material had the arterial system perfused (water at 40°C), injected with stained latex (Neoprene 650), fixed in aqueous formaldehyde solution (10%) and dissected for vessel verification. The arterial circle of this primate is composed of two vascular systems: the vertebra-basilar and the carotid ones, which anastomose to close the arterial circuit. In the caudal portion of the arterial circle, there are the vertebral arteries and their branches: the rostral spinal artery and the caudal inferior cerebellar artery. The anastomosis of the vertebral arteries gives rise to the basilar artery. It presented an anatomical variation at the beginning of its path, forming a double basilar artery, called arterial island. In its course, it emitted branches giving rise to the rostral inferior cerebellar artery, the pontine arteries, the rostral cerebellar arteries, the satellite rostral cerebellar arteries and its terminal branch, the caudal cerebral artery, which presented itself in two segments: the pre-communicating one and post-communicating, joining the internal carotid artery and originating the caudal communicating artery. This group of arteries and anastomoses enclose the caudal portion of the arterial circle. From the right and left internal carotid arteries begins the rostral portion of the arterial circle, which consists of the right and left rostral cerebral arteries and the right and left middle cerebral arteries. The rostral cerebral arteries anastomose into a single trunk, giving rise to the interhemispheric artery, and in A. belzebul and Sapajus libidinosus, the rostral communicating artery is absent. The interhemispheric artery goes to the midbrain region and the corpus callosum knee divides into pericalous artery and callosarginal artery, which will supply the pre and post-central regions of the cerebral hemispheres of this species, as well as other non-human and human primates. It is noted that in the first part of the left rostral cerebral artery, there is a direct inosculation between the recurrent branch of the rostral cerebral artery and left middle cerebral artery to supply the entorhinal region. This fact also occurs in Pongo spp. The middle cerebral artery travels along the lateral sulcus where it emits several superficial branches to irrigate the superior and inferior lateral cortical regions of the frontal, parietal and temporal lobes. It is not part of the arterial circle but is the terminal branch of the internal carotid artery. A. belzebul can be considered to depend on two sources of supply to the brain: the vertebra-basilar and carotid systems, contributing to the intervention of veterinarians during clinical and surgical procedures in other primates, as well as the preservation of wild animals.


2021 ◽  
Vol 11 ◽  
Author(s):  
Jia Li ◽  
Lu Zheng ◽  
Wen-Jie Yang ◽  
Cheuk-Yin Sze-To ◽  
Thomas Wai-Hong Leung ◽  
...  

Objective: Investigating the relevance of the incomplete circle of Willis (COW) to the plaque wall distribution in the atherosclerotic middle cerebral arteries (MCAs) through utilizing high-resolution magnetic resonance imaging (HR-MRI), and its potential clinical impact.Methods: This hospital-based study enrolled consecutive adult patients with acute ischemic stroke or transient ischemic attack, who received a 3.0T Achieva MR system scanning. The COW completeness was evaluated on MR angiography imaging, including anterior (A) and posterior (P)-COW sections. The MCA plaque wall distribution was assessed on HR-MRI. The occurrence of perforator infarction was detected on diffusion-weighted imaging.Results: Among 87 patients (mean age = 62.39 ± 11.64 years old) with atherosclerotic plaques in the MCA M1 segments, the incomplete COW types were more prevalent than the complete COW type (incomplete P-COW, 83.9%; incomplete A-COW, 36.8%; complete COW, 8.1%). The incomplete A-COW had more inferior but fewer ventral plaques of MCA atherosclerosis than the complete A-COW, while the incomplete P-COW had fewer inferior MCA plaques than the complete P-COW. Moreover, symptomatic MCA plaques causing perforator infarctions were more likely to locate on the superior wall.Conclusion: Our findings suggested that the COW completeness could influence the vessel wall distribution of the MCA plaques, among which the superior plaques of symptomatic MCA atherosclerosis was associated with branch occlusive disease.


2021 ◽  
Vol 1 (4) ◽  
pp. 13-18
Author(s):  
Vladislav Nikolaevich Nikitin ◽  
◽  
Ekaterina Valerevna Kozhemyakina ◽  

The brain is one of the most important organs responsible for the health and functioning of the entire body. The blood supply to the brain is carried out through 2 internal carotid and 2 vertebral arteries in norm. The brain, like other body systems, has protective (compensatory) mechanisms aimed at maintaining the necessary blood flow, one of which is the circle of Willis. The article proposes a mechanism for how blood flow is redistributed through the arteries feeding the brain, which is based on the assumption that the central nervous system controls in such a way that it minimizes flows through the connective arteries of the circle of Willis, the flows along which are normal (with symmetry of the left and right sides) practically equal to zero. Сase of the structure of the circle of Willis is considered in norm. The indicated redistribution mechanism is still only the first step towards an attempt to predict cases of changes in blood flow through the cerebral arteries, especially in stroke. In further works, it is planned to consider the inverse problem, i.e. determine the flows through the internal carotid and vertebral arteries, provided that the flows through the cerebral arteries extending from the circle of Willis have normal flow values.


10.12737/5023 ◽  
2014 ◽  
Vol 8 (1) ◽  
pp. 1-6
Author(s):  
Горелик ◽  
E. Gorelik

The purpose of this research is to study the morphology of the hippocampus in the patients with cerebro-vascular disease with age, sex and somatic types. The study was conducted from autopsy material. The hippocampus male (n=20) and female (n=15) of the patients of the second period of mature age were taken for study. Pathological and anatomical examination showed that all dead people had pathology of brain vessels. Changes specific to the 1 and 2 stages of atherosclerosis were detected in the basilar and middle cerebral arteries. Somatotype was defined with the subsequent calculation of the index by the method of Rees-Eysenck. The morphometric research of right and left hippocampus of the brain has been conducted. The parameters of the hippocampus with the sex were determined. There are presented the results of quantitative and qualitative morphological study of the hippocampus in persons of the second period of adulthood with cerebral arteriosclerosis in various somatotypes. The comparative analysis, of morphometric parameters of the hippocampus of the right and left hemispheres of the human brain, showed, that most significant are the length of the hippocampus width of middle part and width region of legs. On microscopic examination of the hippocampus, the individuals of the second period of mature age, even at the early stages of atherosclerosis of cerebral arteries, are detected dystrophic changes of neurons in the CA1 and CA3 regions, showing their ischemic damage.


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