Biochemical etiology of Alzheimer's disease relates to?

AIIMS Bhuvneshwar NO- 2018

Biochemistry and Nutrition

Easy

Appeared in: AIIMS Bhuvneshwar NO- 2018

Explanation

Alzheimer's disease is characterized by a significant loss of cholinergic neurons, which produce acetylcholine.
This leads to a deficiency of the neurotransmitter acetylcholine (ACh) in brain regions vital for memory and learning, such as the hippocampus and cerebral cortex.
This concept, known as the 'cholinergic hypothesis', is supported by evidence of decreased choline acetyltransferase (the enzyme that makes ACh) in the brains of Alzheimer's patients.
The effectiveness of cholinesterase inhibitor drugs in temporarily improving symptoms further validates the importance of the acetylcholine deficit in the disease.

Option B: Epinephrine is a hormone and neurotransmitter primarily involved in the peripheral sympathetic nervous system's 'fight-or-flight' response, not the central cognitive decline seen in Alzheimer's.
Option C: A deficiency in dopamine is the hallmark biochemical cause of Parkinson's disease, primarily affecting the motor system.
Option D: Serotonin is primarily associated with the regulation of mood, sleep, and appetite. While its levels can be altered in Alzheimer's, contributing to depression or anxiety, it is not the primary cause of the core cognitive symptoms.

Visual 1: Diagram: A diagram illustrating a cholinergic synapse. It should show acetylcholine being released, binding to receptors, and then being broken down by acetylcholinesterase. A second panel should show how a cholinesterase inhibitor drug blocks the enzyme, leading to increased acetylcholine levels in the synapse.

Clinical Relevance

Nursing practice connection: Knowing Neurotransmitter basis of Alzheimer's disease helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Understanding the acetylcholine deficit is crucial for nurses administering medications like Donepezil or Rivastigmine. Nurses must monitor for therapeutic effects (temporary improvement in cognition) and cholinergic side effects (e.g., nausea, vomiting, diarrhea, bradycardia).
Patient education should include explaining that these medications manage symptoms but do not cure the disease, emphasizing the importance of adherence and reporting side effects.
What if? If a patient with Alzheimer's is prescribed a new medication with strong anticholinergic properties (e.g., certain over-the-counter sleep aids or drugs for urinary incontinence), the nurse should anticipate a potential worsening of confusion and cognitive symptoms and notify the prescriber.

How to Approach the Question

First, identify the core subject of the question, which is 'Alzheimer's disease'.
Next, focus on the keywords 'biochemical etiology,' which asks for the underlying chemical cause.
Access your knowledge of the major neurotransmitter theories for common neurological disorders.
Recall the primary association: Alzheimer's disease is linked to acetylcholine deficiency. Parkinson's disease is linked to dopamine deficiency. Depression and anxiety are often linked to serotonin and norepinephrine imbalances.
This direct association between Alzheimer's and acetylcholine deficiency points to the correct option.

Concept Tested & Keywords

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