Alzheimer's disease

Definition

Alzheimer's disease is a progressive neurodegenerative disorder characterized by the gradual decline in cognitive function, primarily affecting memory, thinking, and behavior. As the most common cause of dementia, it significantly impacts brain structure and cognitive functions, leading to severe memory disorders and challenges in daily living. The disease is linked to various changes in the brain, including the buildup of amyloid plaques and tau tangles, which disrupt normal neuronal function.

5 Must Know Facts For Your Next Test

1. Alzheimer's disease typically manifests with early symptoms like short-term memory loss, confusion, and difficulty with language and problem-solving.
2. The disease progresses through several stages, from mild cognitive impairment to severe dementia, ultimately affecting the individual's ability to carry out everyday activities.
3. Brain imaging studies often reveal significant atrophy in regions associated with memory, particularly the hippocampus and cerebral cortex, in individuals with Alzheimer's.
4. Genetic factors play a role in Alzheimer's risk; for example, carrying the APOE ε4 allele increases the likelihood of developing the disease.
5. Currently, there is no cure for Alzheimer's disease, but certain medications can help manage symptoms and improve quality of life for affected individuals.

Review Questions

• How does Alzheimer's disease influence cognitive functions and brain structure over time?
  • Alzheimer's disease leads to significant changes in cognitive functions as it progresses. Initially, individuals may experience mild memory issues, which can evolve into more severe impairments affecting reasoning, judgment, and language skills. The brain undergoes structural changes such as atrophy in regions like the hippocampus and cerebral cortex. These alterations contribute to the decline in cognitive abilities and affect daily living activities.
• Discuss the role of amyloid plaques and tau tangles in the pathology of Alzheimer's disease.
  • Amyloid plaques and tau tangles are hallmark features of Alzheimer's disease pathology. Amyloid plaques consist of beta-amyloid peptides that aggregate outside neurons, disrupting cell communication. Tau tangles are formed by hyperphosphorylated tau protein accumulating inside neurons, leading to neurofibrillary degeneration. Together, these abnormalities contribute to neuronal death and the resulting cognitive decline seen in Alzheimer's patients.
• Evaluate the impact of cognitive reserve on the onset and progression of Alzheimer's disease in individuals.
  • Cognitive reserve refers to the brain's ability to cope with damage due to aging or neurological diseases like Alzheimer's. Individuals with higher cognitive reserve—often shaped by education, occupation, and engaging activities—may experience a delayed onset of symptoms despite having similar levels of brain pathology compared to those with lower reserve. This suggests that cognitive reserve might play a protective role against the clinical manifestations of Alzheimer's disease by allowing some individuals to better compensate for neuronal loss.

Related terms

Dementia: A general term for a decline in mental ability severe enough to interfere with daily life, often encompassing a range of symptoms including memory loss and difficulties with thinking.

Neurodegeneration: The progressive degeneration of the structure and function of the nervous system, which can lead to diseases like Alzheimer's and affects cognitive processes.

Cognitive Reserve:

The brain's resilience to neuropathological damage, often influenced by factors such as education and lifestyle, which may affect how Alzheimer's disease impacts an individual.