Acute Ischemic Stroke Treatment: USMLE Question (Answer)

This is the answer and explanation for a USMLE practice question from the Dr. Ray Makar Facebook page. Try it first, then check your answer below.

The Question

A 67-year-old man has sudden right-sided weakness and difficulty speaking that began 2 hours ago. BP is 168/95 mm Hg, glucose is normal, and head CT shows no hemorrhage. He has no contraindications to treatment. What is the most appropriate next step?

A. Aspirin 325 mg and observation
B. Intravenous heparin infusion
C. Lower BP below 140/90 before any treatment
D. MRI of the brain before treatment
E. IV thrombolytic therapy (alteplase or tenecteplase)

Correct Answer: E. IV thrombolytic therapy (alteplase or tenecteplase)

This is an acute ischemic stroke within the 4.5-hour window. Hemorrhage is ruled out on non-contrast CT, glucose is normal and his BP (168/95) is already below the 185/110 limit for thrombolysis. The next step is IV thrombolysis with alteplase or tenecteplase, as soon as possible. Large-vessel occlusions may also need thrombectomy.

Why the Other Answers Are Wrong

Aspirin: Given 24 hours after thrombolysis, or right away for patients who cannot get thrombolytics.
IV heparin: Not used for acute ischemic stroke; it raises bleeding risk without benefit.
Lowering BP below 140/90: Not needed: the goal before thrombolysis is below 185/110.
MRI first: Delays treatment; a non-contrast CT is enough to exclude hemorrhage.