Neuroanatomy USMLE Step 1 Practice Question
A 72-year-old man with a 10-year history of hypertension presents to the emergency department with acute-onset vertigo, nausea, and nystagmus. On examination, he has a right facial droop with preserved forehead wrinkling, loss of pain and temperature sensation over the right face, but loss of pain and temperature sensation over the left arm and trunk. Cranial nerve examination is otherwise intact. Motor and cerebellar examination are normal. MRI of the brain with diffusion-weighted imaging shows an acute ischemic stroke in the brainstem. Which of the following structures is most likely affected?
Answer choices
- AMedial medulla with involvement of the pyramid and medial lemniscus
- BLateral medulla with involvement of the spinothalamic tract and spinal trigeminal nucleusCorrect answer
- CVentral pons with involvement of the corticospinal tract and middle cerebellar peduncle
- DDorsal midbrain with involvement of the oculomotor nucleus and red nucleus
- EVentromedial medulla with involvement of the hypoglossal nucleus and pyramid
- FVentrolateral pons with involvement of the abducens nucleus and corticospinal tract
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