Movement Disorders USMLE Step 1 Practice Question
A 38-year-old woman with childhood rheumatic fever presents with involuntary jerky movements of her face and limbs following a recent streptococcal pharyngitis. Vital signs: BP 118/76, HR 92, RR 18, Temp 37.2°C, SpO2 98% on room air. She displays emotional lability and hypotonia. Notably, she has no fever currently. ESR is elevated at 42 mm/hr. Which of the following best explains the pathophysiologic mechanism underlying this movement disorder?
Answer choices
- ACAG repeat expansion in chromosome 4
- BCopper deposition in the putamen
- CSubthalamic infarction from chronic hypertension
- DLoss of substantia nigra neurons due to alpha-synuclein aggregation
- EAutoimmune injury to basal ganglia structures causing choreaCorrect answer
- FDemyelination of the corticospinal tract secondary to multiple sclerosis
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