Neuroanatomy USMLE Step 1 Practice Question
A 52-year-old man with hypertension presents 2 hours after acute onset of right facial weakness and left-sided hemiparesis. Vital signs: BP 168/94 mmHg, HR 88, RR 16, temp 37°C, SpO2 98%. Neurologic exam reveals right facial droop, left arm/leg weakness, and ipsilateral loss of pain and temperature sensation over the right face. CT head shows acute right brainstem infarct. He denies vertigo or ataxia. Which brainstem structure is damaged?
Answer choices
- AMid-pons with abducens nerve and corticospinal tract
- BUpper medulla with hypoglossal nucleus and pyramids
- CMidbrain with oculomotor nerve and corticospinal tract
- DLateral medulla with spinal trigeminal nucleus and spinothalamic tractCorrect answer
- EMedial medulla with corticospinal tract and CN VII
- FLower pons with trigeminal nerve and medial lemniscus
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