Cerebrovascular Disease USMLE Step 1 Practice Question
A 61-year-old woman with a 6-month history of progressive numbness in her feet and difficulty walking presents with blood pressure 142/88 mmHg, heart rate 78/min, and temperature 37.2°C. Examination reveals loss of vibration sense bilaterally, spasticity in lower extremities, and positive Babinski signs; proprioception is intact. Laboratory studies show macrocytosis with hypersegmented neutrophils and elevated methylmalonic acid. MRI brain demonstrates T2 hyperintensities in the dorsal spinal cord. Which of the following structures is most likely affected?
Answer choices
- ACorticospinal tracts and dorsal columnsCorrect answer
- BCerebellar vermis only
- CSpinothalamic tracts only
- DBasal ganglia only
- EAnterior horn cells only
- FLateral corticospinal tracts and spinocerebellar tracts
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.