A new wave in stroke treatment
The main emergency treatment for most strokes, the drug known as tPA, doesn't always dissolve an artery-plugging clot. Blocked blood flow may keep tPA from reaching the clot, or the clot may be too dense for the drug to penetrate. A little push from ultra-high sound waves may help tPA work faster and better.
In a study published in the November 2004 New England Journal of Medicine, an international team of researchers discovered that applying ultrasound across the temporal bone at the base and side of the skull for up to two hours after the start of tPA completely opened the blocked artery or led to a complete recovery in almost 50% of stroke patients. That's considerably better than the 30% who improved with tPA alone. Risk of bleeding in the brain was no higher with the ultrasound.
It isn't clear how sound waves improve the effectiveness of tPA. They may agitate blood near a clot and pull tPA closer to the obstruction. It's also possible that ultrasound creates tiny, symmetrical holes in the clot, allowing tPA to burrow into it.