Understanding Stroke – 4 Minutes/4 HoursNovember 17th, 2016 by mariska
There are several types of strokes, but for this article – let’s look at the most common – an ischemic stroke (85% of strokes). In this type, a blockage (like a blood clot) occurs and prevents oxygen and nutrients from reaching parts of the brain. Any point downstream of the blocked blood vessel can be affected. Where the blockage occurs determines what side effects a person will experience.
In the first 3-4 minutes, a lack of oxygen causes irreversible cell death. Billions of neurons can die.
Over the next several hours, something called the ischemic cascade can make the problem worse. Without blood and oxygen, there is less ability for the neurons to carry out energy production. Lactic acid can be produced, causing additional cell damage. There is also less energy production because the sodium potassium pump in the cell can’t work properly. When this happens, water rushes into the cells to try to dilute the over-abundance of sodium, causing the cells to swell.
Swelling can cause additional damage and cell death.
Also, within the first 4-6 hours of a stroke, parts of blood vessels can also break down, affecting the blood brain barrier. This barrier is designed to protect the brain from infections, proteins, etc. traveling in the blood stream. Without this barrier completely intact, proteins and water that would usually be blocked from the brain start to leak in, worsening the swelling even more.
What does this mean? If you suspect you or someone you know is having a stroke, you need to get them to a hospital ASAP. There probably is very little you can do in the first 4 minutes. But in the first 4 hours, there are medications that can keep a stroke’s damage from getting much, much worse.
Also know that as the swelling decreases over days, many stroke symptoms will improve. And, with some of the amazing therapies out there today, the brain can learn to work around quite a bit of damage.
To learn more about how to exercise to help improve stroke recovery, check out one of our workshops.