Parkinson's Disease for USMLE Step 2 / COMLEX-USA Level 2

• Motor Symptoms:
• Bradykinesia: Significant slowness of movement, difficulty initiating movements.
• Rigidity: Stiffness in muscles throughout the body.
• Resting Tremor: Noticeable shaking, typically a "pill-rolling" tremor of the hands at rest.
• Postural Instability: Poor balance and coordination, risk of falls.
• Non-Motor Symptoms:
• Cognitive Decline: Ranging from mild impairment to dementia in advanced stages.
• Mood Disorders: Depression and anxiety are common.
• Autonomic Dysfunction: Issues like constipation, urinary urgency, orthostatic hypotension.
• Sleep Disturbances: Especially REM sleep behavior disorder.

• Clinical Diagnosis: Based on motor symptoms and response to dopaminergic therapy.
• Supportive Tests:
• DaTscan: Helps differentiate PD from other types of parkinsonism by assessing dopamine transporter levels in the brain.
• MRI: Used to rule out other causes of symptoms but not diagnostic for PD.

• Pharmacological Treatment:
• Levodopa/Carbidopa: Most effective for symptomatic control, monitored for dose adjustments based on response and side effects.
• Dopamine Agonists: Pramipexole, ropinirole—used in younger patients or early disease.
• MAO-B Inhibitors: Selegiline, rasagiline—used either alone in early disease or as adjunct therapy.
• COMT Inhibitors: Entacapone, tolcapone—enhance effects of Levodopa.
• Non-Pharmacological:
• Physical Therapy: Focus on mobility, strength, and balance.
• Occupational Therapy: Help with daily activities and adaptive techniques.
• Speech Therapy: For speech and swallowing issues.

• Motor Fluctuations and Dyskinesias: Due to long-term Levodopa use.
• Psychiatric Complications: Particularly hallucinations and psychosis, especially in the elderly or those on higher doses of medication.
• Neurological Consultation: For complex cases or when diagnosis is uncertain.

1. Diagnosis of PD: Emphasis on clinical presentation and response to Levodopa. 2. Management Strategies: Detailed knowledge of pharmacological agents used in PD, including their side effects and indications. 3. Differential Diagnosis:

• Essential Tremor: Distinguished by action tremor and lack of other parkinsonian features.
• Drug-Induced Parkinsonism: Caused by dopamine receptor blockers.
• Atypical Parkinsonisms: Like PSP or MSA, which have additional clinical features and poor response to Levodopa.

4. Role of Multidisciplinary Team: Importance of physical, occupational, and speech therapy in managing the disease.