Movement Disorders USMLE Step 1 Practice Question
A 67-year-old man presents with progressive tremor. Vital signs: BP 138/82, HR 78, RR 16, temp 37.2°C, SpO2 98%. On examination, he demonstrates a 4-Hz rhythmic pill-rolling tremor of both hands at rest that diminishes with intentional movement. Gait is normal and strength is intact. MRI brain shows no acute findings. He denies recent medication changes and takes only lisinopril. Which neuroanatomic lesion most likely accounts for his resting tremor that improves with purposeful action?
Answer choices
- ADemyelination of the dorsal columns
- BDegeneration of dopaminergic neurons in the substantia nigra pars compactaCorrect answer
- CInfarction of the subthalamic nucleus
- DLesion of the cerebellar hemispheres
- EDestruction of the caudate nucleus
- FRubral tremor from midbrain lesion
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