A 70-year-old man with a history of atrial fibrillation, not on anticoagulation, presents to the emergency department with sudden-onset left-sided weakness and facial droop. Symptoms began 2 hours ago. Non-contrast CT head is unremarkable for hemorrhage. His NIHSS score is 12. What is the most appropriate next step in management?

The correct answer to the question "A 70-year-old man with a history of atrial fibrillation, not on anticoagulation, presents to the emergency department with sudden-onset left-sided weakness and facial droop. Symptoms began 2 hours ago. Non-contrast CT head is unremarkable for hemorrhage. His NIHSS score is 12. What is the most appropriate next step in management?" is Option B: Initiate intravenous tissue plasminogen activator (tPA).

The other options — A) Administer aspirin, C) Start subcutaneous heparin, D) Schedule for carotid endarterectomy — are incorrect for this USMLE Exam Prep question. As explained above: This patient presents with an acute ischemic stroke within the therapeutic window (within 4.5 hours of symptom onset) and no contraindications on non-contrast CT. Intravenous tPA is indicated to rest…