Bonnie is a 70-year-old woman who lives alone. One evening, she felt light-headed and dizzy. When her head began to ache, she decided to take an analgesic and go to bed early. The following morning, upon awakening, she was unable to move the bed sheets with her right arm. At this point, she was experiencing tingling sensations in her limbs, and she had difficulty keeping her balance. She dialed 911 for help, and by the time the ambulance arrived, she was confused and unable to articulate her words although she knew what information he was asking of her. In the hospital, she was examined and treated for ischemic stroke.
1. Stroke, or brain attack, involves brain tissue injury. Describe ischemic penumbra and what factors contribute to the survival of the neurons involved. What happens if the cells of the penumbra are unable to be preserved?
2. Compare and contrast hypoxia and ischemia. What condition is more dangerous to the brain? Explain your answer.
3. Knowing what you do about the effects of ischemia on the brain, why would someone with ischemic stroke develop cerebral edema?
4. What type of aphasia was Bonnie exhibiting when talking to her caregivers? Explain your answer.
Expert Solution Preview
Introduction: This assignment will cover a scenario of a 70-year-old woman who experienced an ischemic stroke. It will provide questions that require the student to describe and compare different types of brain injuries and their effects on the brain.
1. Ischemic penumbra refers to the area surrounding the core of an ischemic stroke where brain tissue is at risk of permanent damage but isn’t dead yet. Factors such as cerebral blood flow, glucose availability, and oxygen demand contribute to the survival of neurons involved. If the penumbra cells are unable to be preserved, they may undergo irreversible damage and develop into the core of the stroke, leading to cell death and brain injury.
2. Hypoxia refers to a lack of oxygen supply to the brain, while ischemia refers to a lack of blood supply to the brain. Both conditions can lead to brain damage, but ischemia is more dangerous as it can lead to irreversible damage to brain cells and can have a more immediate impact on brain function. Hypoxia can be caused by many factors, whereas ischemia is usually caused by a clot or atherosclerosis in a blood vessel.
3. Brain edema is a swelling of the brain, caused by the accumulation of fluids within the brain tissue. This swelling can occur due to an ischemic stroke because the blood supply to the brain has been disrupted, and the brain tissue is deprived of important nutrients and oxygen. As a result, the brain may try to compensate for the lack of nutrients by increasing the amount of fluid in the tissue, leading to brain edema.
4. Bonnie was exhibiting Broca’s aphasia when speaking to her caregivers. This type of aphasia is caused by damage to the frontal lobe of the brain, specifically in the area responsible for producing speech. Individuals with Broca’s aphasia may have difficulty speaking fluently but can usually understand what others are saying to them. This supports Bonnie’s ability to understand the paramedic’s questions but not articulate her answers.