A 72-year-old male presents to the ED with sudden-onset left-sided weakness and slurred speech that resolved completely within 30 minutes. His medical history includes hypertension and hyperlipidemia. A non-contrast head CT scan is negative for acute hemorrhage or infarct. What is the most appropriate next diagnostic step?

The correct answer to the question "A 72-year-old male presents to the ED with sudden-onset left-sided weakness and slurred speech that resolved completely within 30 minutes. His medical history includes hypertension and hyperlipidemia. A non-contrast head CT scan is negative for acute hemorrhage or infarct. What is the most appropriate next diagnostic step?" is Option D: Schedule an immediate MRI of the brain with diffusion-weighted imaging.

The other options — A) Initiate aspirin and discharge home, B) Obtain a carotid duplex ultrasound, C) Perform a lumbar puncture — are incorrect for this USMLE Exam Prep question. As explained above: For a transient ischemic attack (TIA) with a negative non-contrast CT, an MRI of the brain with diffusion-weighted imaging (DWI) is the most sensitive test to detect acute infarcts and should be perf…