ASC Acute Stroke Care & Treatment 3 — Questions and Answers
Question 1: The DAWN and DEFUSE-3 trials extended mechanical thrombectomy eligibility to patients presenting up to how many hours after last known well?
- 6 hours
- 12 hours
- 16 hours
- 24 hours (Correct answer)
Correct answer: 24 hours
The DAWN trial extended thrombectomy to 24 hours using clinical-imaging mismatch criteria, while DEFUSE-3 extended to 16 hours using perfusion imaging.
Question 2: Which imaging modality is MOST useful for identifying the ischemic penumbra (salvageable brain tissue) in late-presenting stroke patients?
- Non-contrast CT head
- CT angiography of neck vessels
- CT perfusion or MRI perfusion-diffusion mismatch (Correct answer)
- Transcranial Doppler ultrasound
Correct answer: CT perfusion or MRI perfusion-diffusion mismatch
CT perfusion or MRI perfusion-diffusion mismatch identifies penumbra (at-risk but viable tissue) versus core infarct for late-window treatment decisions.
Question 3: A 70-year-old patient on warfarin with INR of 1.6 presents with acute ischemic stroke within 3 hours. What is the appropriate tPA decision?
- Administer tPA — INR < 1.7 is acceptable (Correct answer)
- Withhold tPA — any anticoagulant use is a contraindication
- Administer half-dose tPA given anticoagulation
- Administer tPA only if NIHSS > 10
Correct answer: Administer tPA — INR < 1.7 is acceptable
IV tPA may be given to patients on warfarin if the INR is ≤ 1.7, as this level does not confer excessive hemorrhagic risk.
Question 4: What is the recommended door-to-needle time target for IV tPA administration in acute ischemic stroke?
- 30 minutes
- 45 minutes
- 60 minutes (Correct answer)
- 90 minutes
Correct answer: 60 minutes
The AHA/ASA recommends a door-to-needle time of ≤ 60 minutes for IV tPA to maximize treatment benefit.
Question 5: Aspirin therapy after acute ischemic stroke treated with IV tPA should be initiated at what time point?
- Immediately after tPA infusion completes
- At 12 hours post-tPA
- At 24 hours post-tPA after repeat CT shows no hemorrhage (Correct answer)
- At 48 hours post-tPA regardless of imaging
Correct answer: At 24 hours post-tPA after repeat CT shows no hemorrhage
Antiplatelet agents should be withheld for 24 hours after tPA and initiated only after repeat imaging confirms no hemorrhagic transformation.
Question 6: Which intervention is recommended for large hemispheric infarction (malignant MCA syndrome) in patients under age 60 to reduce mortality?
- High-dose corticosteroids
- Osmotic therapy with mannitol alone
- Decompressive hemicraniectomy (Correct answer)
- Therapeutic hypothermia
Correct answer: Decompressive hemicraniectomy
Decompressive hemicraniectomy within 48 hours significantly reduces mortality in malignant MCA infarction in patients ≤ 60 years old.
Question 7: A patient receives mechanical thrombectomy with successful TICI 2b reperfusion. What blood pressure target is recommended in the first 24 hours post-procedure?
- < 120/80 mmHg
- < 140/90 mmHg (Correct answer)
- < 180/105 mmHg
- No specific target needed
Correct answer: < 140/90 mmHg
Following successful reperfusion, blood pressure should be maintained below 140/90 mmHg to reduce reperfusion injury and hemorrhagic transformation.
ASC Acute Stroke Care & Treatment 3
The DAWN and DEFUSE-3 trials extended mechanical thrombectomy eligibility to patients presenting up to how many hours after last known well?