Neuroanatomy USMLE Step 1 Practice Question
A 35-year-old man is brought to the emergency department after blunt head trauma to the right temporal region during a motor vehicle accident. He was initially unconscious for approximately 2 minutes, then regained alertness and appeared oriented. His wife reports that approximately 3 hours after the accident, he became increasingly drowsy and complained of severe headache. On examination, his vital signs are BP 168/98 mmHg, HR 108 bpm, RR 22/min. He has a dilated right pupil that is nonreactive to light, and demonstrates left-sided lower extremity weakness with hyperreflexia. A noncontrast head CT shows a lens-shaped hyperdense collection between the skull and dura mater in the right temporal region. Which of the following anatomical structures is being compressed by the expanding hematoma, accounting for his current clinical presentation?
Answer choices
- ARight oculomotor nerve at the tentorial notchCorrect answer
- BRight abducens nerve at Dorello's canal
- CRight trochlear nerve near the midbrain
- DRight optic nerve at the optic canal
- ERight posterior cerebral artery at the posterior communicating artery junction
- FRight middle cerebral artery at the sylvian fissure
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