A case of cerebrovascular accident
1. Define the terms ischemia and infarction. Ischemia- local decrease in blood supply Infarction- death & deterioration of tissue resulting from lack of blood supply.
2. What is a stroke? Name the two main types of strokes and describe the mechanism(s) by which each type occurs.
Cerebrovascular Accident- condition in which brain tissue is deprived of blood supply. The most common stroke symptoms are:
Numbness or weakness (paresis) of the face, arm, or leg, sometimes only on one side;
Confusion, trouble speaking or understanding speech (aphasia)
Trouble seeing
Trouble walking or dizziness; loss of balance or coordination (ataxia)
Severe headache with no known cause
1. Ischemic stroke (~83%) - blood vessel supplying brain tissue is blocked by a blood clot. a. cerebral thrombus b. cerebral embolism 2. Hemorrhagic stroke (~17%) - A blood vessel breaks open, causing blood to leak into the brain.
3. Define the term collateral blood flow, and describe how this and other factors affect the development of stroke.
The brain has s circular vascular structure called the circle of Willis and two pairs of arteries that feed the circle. So most areas of the brain receive blood from more than one collateral blood vessel. The type, and severity of stroke symptoms depends on the location of the severity of brain ischemia.
4. List the risk factors that predispose an individual to suffer a stroke. What are the five warning signs that indicate an individual is having a stroke? Which of the risk factors and warning signs did Mr. Dexter possess based on the clinical history?
Risk factors for ischemic stroke include hypertension, age, cigarette smoking, male gender, family history, race, previous stroke, carotid stenosis >80%, atrial fibrillation, congestive heart failure, mitral stenosis, prosthetic cardiac valves, myocardial infarction, and drug abuse (e.g., cocaine). 7 Other factors that may contribute to stroke are diabetes, obesity, a
2. What is a stroke? Name the two main types of strokes and describe the mechanism(s) by which each type occurs.
Cerebrovascular Accident- condition in which brain tissue is deprived of blood supply. The most common stroke symptoms are:
Numbness or weakness (paresis) of the face, arm, or leg, sometimes only on one side;
Confusion, trouble speaking or understanding speech (aphasia)
Trouble seeing
Trouble walking or dizziness; loss of balance or coordination (ataxia)
Severe headache with no known cause
1. Ischemic stroke (~83%) - blood vessel supplying brain tissue is blocked by a blood clot. a. cerebral thrombus b. cerebral embolism 2. Hemorrhagic stroke (~17%) - A blood vessel breaks open, causing blood to leak into the brain.
3. Define the term collateral blood flow, and describe how this and other factors affect the development of stroke.
The brain has s circular vascular structure called the circle of Willis and two pairs of arteries that feed the circle. So most areas of the brain receive blood from more than one collateral blood vessel. The type, and severity of stroke symptoms depends on the location of the severity of brain ischemia.
4. List the risk factors that predispose an individual to suffer a stroke. What are the five warning signs that indicate an individual is having a stroke? Which of the risk factors and warning signs did Mr. Dexter possess based on the clinical history?
Risk factors for ischemic stroke include hypertension, age, cigarette smoking, male gender, family history, race, previous stroke, carotid stenosis >80%, atrial fibrillation, congestive heart failure, mitral stenosis, prosthetic cardiac valves, myocardial infarction, and drug abuse (e.g., cocaine). 7 Other factors that may contribute to stroke are diabetes, obesity, a