A nursing student asks the nurse to differentiate the pathology of Alzheimer's disease from that of Parkinson's disease. Which description is correct?

The correct answer is A. In Parkinson's disease, there is a reduction in dopamine levels due to the degeneration of dopaminergic neurons in the substantia nigra of the brain. This imbalance leads to motor symptoms such as tremors and rigidity. In contrast, Alzheimer's disease is characterized by the accumulation of beta-amyloid plaques and neurofibrillary tangles, leading to neuronal cell death and cognitive decline. The incorrect choices can be eliminated as follows: B is incorrect because Parkinson's disease is associated with a decrease, not an increase, in dopamine levels. C is incorrect as Alzheimer's disease is not primarily characterized by decreased dopamine levels but rather by the accumulation of plaques and tangles. D is incorrect as Alzheimer's disease is not associated with an excess of acetylcholine but rather a decrease in its levels. Therefore, option A is the correct choice as it accurately describes the pathology of Parkinson's disease.