A client asks the nurse what causes Parkinson disease. Which description of pathology would the nurse provide in response to the client ?
A: Disintegration of the myelin sheath
B: Breakdown of upper and lower neurons
C: Reduced acetylcholine receptors at synapses
D: Degeneration of neurons of the basal ganglia
The correct answer and explanation is:
The correct answer is D: Degeneration of neurons of the basal ganglia.
Parkinson’s disease is a neurodegenerative disorder that primarily affects the basal ganglia, which is a group of structures deep within the brain responsible for coordinating movement. The most significant pathological feature of Parkinson’s disease is the degeneration of dopaminergic neurons in the substantia nigra, a part of the basal ganglia. These neurons produce dopamine, a neurotransmitter that plays a crucial role in regulating movement, emotional responses, and other functions.
As these dopaminergic neurons degenerate and die, the brain’s ability to control and coordinate muscle movements is impaired. Dopamine deficiency in the basal ganglia leads to the hallmark motor symptoms of Parkinson’s disease, including tremors, rigidity, bradykinesia (slowness of movement), and postural instability.
Other potential causes of Parkinson’s disease can include genetic factors, environmental toxins, and oxidative stress, but the central pathology is the degeneration of dopaminergic neurons. This degeneration is not a result of the disintegration of the myelin sheath (Option A), which is seen in conditions like multiple sclerosis. The breakdown of both upper and lower motor neurons (Option B) is more characteristic of diseases like amyotrophic lateral sclerosis (ALS). Reduced acetylcholine receptors at synapses (Option C) is also not a feature of Parkinson’s disease and is more relevant to conditions like Alzheimer’s disease, where cholinergic dysfunction plays a key role.
Thus, the primary cause of Parkinson’s disease is the progressive degeneration of neurons in the basal ganglia, leading to a deficiency in dopamine and subsequent motor impairments.