Why is last-known-well time important in suspected stroke?

• A. It determines the patient's age
• B. It determines the need for antibiotics
• C. It determines eligibility for thrombolytic therapy and time-critical intervention
• D. It determines blood type

Answer: (C)

Time is critical in stroke care; treatment windows hinge on when the patient was last known well. The last-known-well time sets the clock for whether a patient is within the window to receive thrombolytic therapy (such as IV alteplase) and other time-sensitive interventions like mechanical thrombectomy. Typically, IV thrombolysis is considered within about 4.5 hours of onset in eligible patients, and thrombectomy can be pursued in extended windows for certain cases based on imaging and guidelines. If the last-known-well time is unknown or beyond the recommended window, thrombolysis is usually not indicated due to bleeding risk. In wake-up strokes, imaging criteria may determine eligibility, but the starting point for the decision remains how long the patient has been well. So, last-known-well time directly informs eligibility for clot-busting therapy and other time-critical actions. It doesn’t determine age, need for antibiotics, or blood type.