Why is immediate, emergent care so important for a stroke?

Time is brain. The sooner you can stop stroke progress, the more brain tissue is prevented from permanent damage and the more partially-injured brain tissue can be salvaged. Cva=911. Don't forget that equation. Take Aspirin 325 mg at first sign of a stroke and dial 911!
Time = brain. Just as in a heart attack, a stroke occurs when blood flow is blocked in one of the arteries that supplies the brain. The faster the artery is opened and blood flow is re-established, the less the damage will be.