Movement Disorders USMLE Step 1 Practice Question
A 71-year-old man with Parkinson disease on levodopa/carbidopa for 8 years develops sudden uncontrolled dyskinetic movements of the limbs and trunk for 30 minutes after each dose of medication, alternating with periods of rigidity and bradykinesia. His doses have been escalated progressively. Which of the following best explains this phenomenon?
Answer choices
- AMedication-induced tardive dyskinesia
- BAcute stroke involving the basal ganglia
- CMotor fluctuations and levodopa-induced dyskinesiaCorrect answer
- DDevelopment of Lewy body dementia
- EProgression of underlying Parkinson disease
- FWearing-off effect with concurrent dopamine agonist-induced psychosis
See the full explanation
Get the correct-answer rationale, why each distractor is wrong, the underlying mechanism, and high-yield associations — plus adaptive practice that targets your weak areas — with a free MedBoardPRO account.