This would buy the brain time until clot-busting drugs could be given in hospital.

BBC: Brain's 'stroke shielding' cracked

In some instances giving patients the clot-busting drugs could make damage to the brain worse.

CNN: Bluetooth device to save stroke victims

Dominating the market for clot-busting technology is Possis Medical (nasdaq: POSS - news - people ).

FORBES: OmniSonics' Clot Buster

New clot-busting drugs allow some stroke patients to make a full recovery if treated within three hours of their attack.

CNN: Bluetooth device to save stroke victims

But we need to find out why some people bleed and how to reduce this to increase the effectiveness of clot-busting treatment.

BBC: Brain

For now, treatment of strokes is pretty much limited to Genentech's clot-busting drug, Activase, a tissue plasminogen activator, which is primarily used to treat heart attacks.

FORBES: Repairing The Brain

Dr Thiemann says there are several possible reasons for differences between the new findings and the conventional wisdom, which was based on research trials of clot-busting drugs conducted about a decade ago.

BBC: Heart attack drug 'can kill'

One study found that chest-pain patients who were treated aggressively -- with, say, angioplasty, cardiac bypass or sophisticated clot-busting drugs -- did better than those whose doctors took a "wait and see" approach.

CNN: Research closing in on heart disease

Premature deaths from heart disease - the single biggest killer - are down by a quarter since 1997, with a third more heart operations, twice as many patients receiving immediate access to clot-busting drugs and cholesterol lowering drugs now prescribed to 1.8 million people.

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