Case A: 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 an ischemic stroke. 1.A 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? A: The ischemic contention zone is a band of neurons that surrounds a core of dead or dying cells caused by a stroke. The disputed zone c

Case A: 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 an ischemic stroke. 1.A 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? A: The ischemic contention zone is a band of neurons that surrounds a core of dead or dying cells caused by a stroke. The disputed zone c

Dementia involves the deterioration of intellect to the extent that it interferes with occupational or social activity. Any disorder that damages the areas of the brain involved with memory and learning can result in dementia. Problem solving, memory, judgment, abstract thought, language, perception, and motor skills may all be affected in the presence of dementia.

Macroscopically, there is loss of neurons with cortical atrophy, particularly in the parietal and temporal lobes. The gyri narrow and the sulci deepen as tissue atrophies. The ventricles are also affected and enlarge as the brain mass declines.
Microscopically, neuritic plaques and neurofibrillary tangles characterize Alzheimer disease. Neuritic plaques (or senile plaques) consist of degenerating nerve terminals that form clusters around a neurotoxic amyloid β-peptide nucleus. The plaques are largely found in the neocortex, hippocampus, and isocortex. Neurofibrillary tangles develop in the cytoplasm of neurons. The tangles are composed of fibrous proteins and hyperphosphorylated tau proteins wrapped tightly in a helical fashion. They are resistant to enzymatic breakdown and compromise the function of the neuron they inhabit.

The hippocampus is central to the encoding and consolidation of short-term memory and retrieval of long-term memory. It is also responsible for the processing of information. In Alzheimer disease, the hippocampus is particularly vulnerable to the development of neuritic plaques and neurofibrillary tangles. The production of choline acetyltransferase (an enzyme responsible for the synthesis of acetylcholine) declines as a result. When acetylcholine is deficient, the formation and processing of memory by the hippocampus are compromised.