Impaired Cerebral Blood Flow Disorders
CEREBRAL BLOOD FLOW
Impaired cerebral blood flow disorders are extremely common and factors such as the lesion site, existing collateral’s, and the amount of tissue affected determines the actual neurological deficit that results. The impaired blood flow may have a number of causes. Things such as alterations in blood pressure, changes in the arterial walls, and occlusions of the arterial lumen are some of the more important causes.
The brain is supplied with blood by two internal carotid arteries and two vertebral arteries. These arteries form the anastomosis known as the Circle of Willis. In 1951, two researchers, McDonald and Potter demonstrated that, "the blood supply to half of the brain is provided by the internal carotid and vertebral artery of that side, and that their respective streams come together in the posterior communicating artery at a point where the pressure of the two is equal and they do not mix." (Snell, p514). This is important to keep in mind when considering just how significant the collateral circulation truly is. "If, however, the internal carotid or vertebral artery is occluded, the blood passes forward or backward across that point to compensate for the reduction in blood flow. The circulus arteriosus also permits the blood to flow across the midline, as shown when the internal carotid or vertebral artery on one side is occluded." This provides some relief for occlusions in the major vascular supply. Another important finding, was that the blood that flows from the two vertebral arteries remain on the same side of the lumen and does not mix while passing through the basilar artery. These are important items for the major vascular supply, however, once...
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...ain focus of the physician in treating a stroke patient must be the individual patient and his/her underlying lesion. Cerebral blood flow deficiency is not limited in its scope of patients it can afflict. The care of stroke patients is changing and the optimal management of the patient’s condition demands the careful consultation of a well-informed team of physicians.
Works Cited:
Auer, L. M. & Ladurner, G. "Alterations of the Cerebral Blood Volume," p.p. 233-38.
Snell, R. S. "The Blood Supply of the Brain," Clinical Neuroanatomv for Medical Students. Little, Brown and Co., Boston/Toronto, p.p. 507-24.
Stern, B. J. "Cerebrovascular Disease and Pregnancy’ Neurological Disorders of Pregnancy". p.p. 32-34.
Walton, John. "Disorders of the cerebral circulation," Brains Diseases of the Central Nervous System. Oxford Univ. Press, New York; p.p. 219.
Walton, Sir John. Brain's Diseases of the Nervous System. Oxford University Press. New York, 1955, pp. 365.
On February 11, 2014, a 64 year old female began having tingling and numbness in her right side and face, she notified family and they called 911 to dispatch an ambulance to her home. The ambulance transported her to Ellis Medicine’s emergency room on Nott Street in Schenectady. In the emergency room her main complaints and symptoms were right-side weakness, headache, nausea, and decreased level of consciousness. The symptoms were consistent with signs and symptoms of a stroke. A CAT scan and MRI show a left-sided cerebral hemorrhage. The Neuroscience team diagnosed her with Amyloid Angiopathy, a genetic disorder that causes protein to deposit on the walls of blood vessels in the brain. Deposits cause the blood vessel walls to break and crack. Blood leaks into the brain causing damage and hemorrhagic stroke (Angiopathy, 2013).
“Myotonic Dystrophy.” Human Diseases and Conditions. Ed. Neil Izenberg. Vol. 2. New York: Charles Scribner’s Sons, 2000.
Cerebral Vascular Accident also known as a stroke occurs when part of the brain loses its blood supply and the part of the body that the blood-deprived brain cells control stops working. Blood loss supply can be ischemic because of lack of blood flow, or hemorrhagic because of bleeding into brain tissue. When an artery in the brain is being obstructed or blocked preventing oxygen rich blood from being delivered to brain cells, an ischemic stroke can occur (Wedro, 2013).
Capital structure is the composition of the company 's capital value and the proportion of the relationship which can reflect the company 's structural stratification and core competitiveness of the company 's business performance also has unpredictable impact on market value, shareholder wealth and even sustainable development capacity . Through the analysis of the equity ratio, the debt ratio, the long-term debt ratio, the return on assets and the Modigliani and Miller theory, Sainsbury 's capital structure is stable.
Komaroff, Anthony L. "Brain and Nervous System." The Harvard Medical School Family Health Guide. New York: Simon & Schuster, 1999. 375-77. Print.
The Modigliani-Miller theorem, proposed by Franco Modigliani and Merton Miller, forms the basis for modern thinking on capital structure, though it is generally viewed as a purely theoretical result since it assumes away many important factors in the capital structure decision. The theorem states that, in a perfect market, the value of a firm is unaffected by how that firm is financed. This result provides the base with which to examine real world reasons why capital structure is relevant, that is, a company's value is affected by the capital structure it employs. These other reasons include bankruptcy costs, agency costs and asymmetric information. This analysis can then be extended to look at whether there is in fact an 'optimal' capital structure: the one which maximizes the value of the firm.
A stroke is a serious occurrence that is considered to be a medical emergency, according to CDC.gov. Strokes happen when either a blood clot in the brain blocks blood flow carrying vital oxygen, or a blood vessel breaks within the brain and oxygen does not arrive at specified locations. (CDC.gov/Stroke Fact Sheet) Oxygen is imperative for brain function. According to CDC.gov, the brain utilizes approximately twenty percent of the body’s oxygen intake; without a continuous intake of oxygen, brain cells begin to die. According to stroke.org, every single minute before a stroke can be treated, an estimated 1.9 million neurons are lost, which is why it is important to know the signs and symptoms of
Walton, Sir John. Brain’s Diseases of the Nervous System. 9th ed. Oxford University Press. Oxford: 1985.
A stroke can be generally be defined in two types of categories. The first and most common type of stroke is called ischemic stroke. This occurs when a blood clot (cerebral thrombosis) blocks a blood vessel in the brain. Blood flow beyond the blood clot is then restricted, and the part of the brain that relies on that blood supply becomes oxygen deficient and can die (1). A blood clot can develop in a narrowed artery that supplies the brain or can travel directly from the heart (or somewhere in the body) to an artery that supplies the brain. Blood clots are usually the result of other issues in the body that affect the normal blood flow. Common problems that affect the normal blood flow include: hardening of the arteries, irregular heart rhythms, infection of the heart valves, congenital heart defects, blood clotting disorders, inflammation of the blood vessels, etc. (2)
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