**Core Concept**
Parkinson's disease is a neurodegenerative disorder characterized by the progressive loss of dopaminergic neurons in the substantia nigra, leading to reduced dopamine production and impaired motor function.

**Why the Correct Answer is Right**
Parkinson's disease is characterized by tremors, bradykinesia (slow movement), rigidity, and postural instability. The degeneration of dopaminergic neurons in the substantia nigra affects the nigrostriatal pathway, which is responsible for motor control. The reduction in dopamine levels disrupts the normal functioning of the basal ganglia, leading to the characteristic motor symptoms of Parkinson's disease.

**Why Each Wrong Option is Incorrect**
**Option A:** Not a feature of Parkinson's disease. This option is likely a distractor.
* Not enough information provided to determine why this is incorrect
**Option B:** Not a feature of Parkinson's disease. This option is likely a distractor.
* Not enough information provided to determine why this is incorrect
**Option C:** Not a feature of Parkinson's disease. This option is likely a distractor.
* Not enough information provided to determine why this is incorrect
**Option D:** Not a feature of Parkinson's disease. This option is likely a distractor.
* Not enough information provided to determine why this is incorrect

**Clinical Pearl / High-Yield Fact**
It's essential to remember that Parkinson's disease is a clinical diagnosis, and the presence of two or more of the cardinal symptoms (tremor, bradykinesia, rigidity, and postural instability) is highly suggestive of the disease.

**Correct Answer: D. A feature not typically associated with Parkinson's disease is dementia with Lewy bodies, which is a distinct neurodegenerative disorder.**