Because we’re talking about brain tissue, one fact is worth stating: brain tissue doesn’t grow back. It’s one of the few tissues in the body where once the brain matures, that’s all you get! So when blood flow is interrupted, you better get it back in a hurry! (New studies are indicating some portions of the brain can revert back to an embryonic state in some conditions, but that’s developing research.)
The two types of strokes are ischemic (that is, caused by a blood clot) and hemorrhagic (caused by a weakened blood vessel that’s burst.) Ischemic strokes are by far the most common (87% of strokes are ischemic). If a stroke is ischemic, and the patient can get immediate treatment, a clot-busting drug can be given within three hours after the onset of the symptoms.
In the image on the right, a clot-busting drug is administered to a patient suffering from an ischemic stroke, and the results are impressive. But keep in mind how quickly the time elapses when you’re having any kind of medical emergency for the first time. If you live near a hospital, and someone can drive you there, you might get there in 60-90 minutes from the onset of symptoms (if the stroke was instantly identified). If the hospital is ready for you, the MRI would take 30 minutes, and then it would need to be reviewed (another 30 minutes), and if a clot-buster is called for 30 more minutes to prep and administer it. You’d be hard-pressed to get it in in under three hours! (The image on the right was likely taken from a patient already in the hospital.)