The golden three hour tPA window for stroke treatment

Stroke treatment has undergone a number of significant advances since the 1990's, and the most important of these is still believed to be the use of Tissue Plasminogen Activator (tPA) for stroke.  Researchers in the 1990s began using tPA for the treatment of ischemic stroke. Over 80% of all strokes are ischemic, which means that they are caused by blood clots that interrupt blood flow in an area of the brain.

tPA acts by dissolving these stroke-causing blood clots. Its efficacy has been proven by several large clinical trials which show a greater chance of recovery in stroke patients who are treated with it. However, these trials also show that, if given later than three hours after a person first realizes he/she is having stroke symptoms, tPA can cause dangerous bleeding in the brain. Consequently, it is only safe to give tPA within 3 hours of the beginning of stroke symptoms, which is why physicians think of this time as the "golden three hour tPA window".

Unfortunately, the 3 hour window is often missed because it is often difficult for people to get to the hospital within 3 hours of the start of a stroke. Because of this only a small fraction of stroke patients receives tPA. A new way of getting patients to the hospital sooner for tPA treatment is called the Mobile Stroke Unit. Started in Germany, Mobile Stroke Units have been adopted in Houston, Texas and Cleveland, Ohio as a way to get stroke patients evaluated while they are still on the way to the hospital.

This may help more patients get tPA within the three hour window.

Perhaps the most common cause of delay in getting tPA is the lack of awareness about stroke signs and symptoms. Most people wait up to a day after their symptoms start before seeking medical attention because they simply don't know their symptoms are those of a stroke.

Many organizations are now working to correct this knowledge gap so that more people affected by stroke can benefit from tPA. You can help get this much needed treatment to those who one day might need it by learning how to recognize the symptoms of a stroke. If you know the signs and symptoms of stroke, teach them to your parents, your children and other people around you. This simple act of kindness might one day make a major difference in their lives if they ever suffer a stroke.

Recommended reading:
What are the symptoms of a stroke?
The stroke team
Intra-arterial thrombolysis

Edited by Heidi Moawad MD

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