A 75-year-old banker presents with complaints of increasing difficulty doing up his shi buttons every morning and brushing his teeth. On examination dental hygiene is good and you notice that his hand shakes slightly when he is relaxing in front of the TV but stops when he reaches for the TV remote, and he is able to switch channels. What is the best initial management step?

**Core Concept**
Parkinson's disease is a neurodegenerative disorder characterized by the loss of dopamine-producing neurons in the substantia nigra, leading to a deficiency in dopamine and the subsequent development of motor symptoms such as tremors, rigidity, bradykinesia, and postural instability.

**Why the Correct Answer is Right**
The patient's complaints of difficulty doing fine motor tasks such as buttoning his shirt and brushing his teeth, combined with the presence of a resting tremor that improves with action, are highly suggestive of Parkinson's disease. The improvement in tremor with voluntary movement (e.g., reaching for the TV remote) is a classic feature of Parkinson's disease. The best initial management step would be to initiate dopaminergic therapy to alleviate the patient's motor symptoms.

**Why Each Wrong Option is Incorrect**
**Option A:** Starting physical therapy would be premature without first addressing the patient's motor symptoms with pharmacological therapy.
**Option B:** Ordering an MRI of the brain may be useful later in the diagnostic workup, but it is not the best initial management step.
**Option C:** Prescribing a muscle relaxant would not address the underlying cause of the patient's symptoms and may even worsen the tremor.

**Clinical Pearl / High-Yield Fact**
The "4 As" of Parkinson's disease management are:
* A: Assessment (of motor symptoms)
* A: Aspiration (of a diagnosis)
* A: Action (initiation of dopaminergic therapy)
* A: Adjustment (of therapy as needed)

**Correct Answer: C. Prescribing a dopaminergic agent such as levodopa/carbidopa or a dopamine agonist.**

✓ Correct Answer: C. Prescribe L-Dopa