When someone has a blood clot in the brain causing an ischemic stroke, it must be broken up as quickly as possible to restore blood flow and avert brain damage. That is usually done with drugs; researchers tried supplementing the drugs with ultrasound.

What the researchers wanted to know: Is it safe to zap blood clots in the brain with ultrasound?

What they did: One hundred twenty-six patients were used in the study (either they or whoever was legally responsible for them gave permission). Within three hours after a stroke, each patient was given intravenous tissue plasminogen activator (t-PA), the usual way to clear up the blockage that causes an ischemic stroke. Half the patients got two hours of ultrasound, and the other half just spent two hours in the head frame under an ultrasound unit, so they wouldn't know they weren't getting the ultrasound.

What they found: People who had the ultrasound were more likely to have their blocked arteries clear up within two hours. Ultrasound is thought to make t-PA work better by jiggling the blood clot around and making more of it accessible to the medicine.

What the study means to you: Restoring blood flow to the brain is the key to avoiding serious brain damage after stroke. This is a small preliminary study, though. More research would show just how helpful ultrasound is likely to be and whom it is best for.

Caveats: Since the sonographers who were monitoring the blood vessels to see if they'd opened up were also running the therapeutic ultrasound, they knew which treatment group the patient was in. Also, using ultrasound this way is quite difficult, and the treatment probably wouldn't work as well with less skillful sonographers.

Find out more: Information about t-PA from the American Heart Association

Read the article: Alexandrov, A.V. et al. "Ultrasound-Enhanced Systemic Thrombolysis for Acute Ischemic Stroke." New England Journal of Medicine. Nov. 18, 2004, Vol. 351, No. 21, pp. 2170–2178.

Abstract online: http://content.nejm.org