Stroke therapy window might be extended past nine hours for some

Feb 09, 2009

Some patients who suffer a stroke as a result of a blockage in an artery in the brain may benefit from a clot-busting drug nine or more hours after the onset of symptoms. The findings are published in the online edition of Radiology.

"Stroke is the third leading cause of death in the U.S.," said the study's lead author, William A. Copen, M.D., Director of Advanced Magnetic Resonance Neuroimaging at Massachusetts General Hospital (MGH) in Boston. "Every hour that we can add to the treatment window would allow vastly more stroke patients to be treated with potentially life-saving therapy."

The most common type of stroke is called ischemic stroke. These strokes occur when a blood clot blocks a blood vessel supplying blood to the brain. Some ischemic strokes can be treated with thrombolytic, or clot-busting, therapy using tissue plasminogen activator (t-PA), which helps dissolve the blockage. However, the window of opportunity to safely administer the medication is generally considered to be just three hours. Because few patients get to the hospital to be diagnosed and treated within that time frame, fewer than seven percent of patients receive the drug.

In this retrospective study, researchers analyzed the test results of 109 ischemic stroke patients at MGH. The testing methods included two different MRI scanning techniques: perfusion MRI, which measures blood flow in the brain, and diffusion MRI, which measures the movement of water molecules in tissue.

"Comparing the lesions that we see in these two MR images reveals which areas of the brain are threatened by a lack of blood flow, but could still be salvageable," Dr. Copen said. "A mismatch between the lesions suggests that a patient might still benefit from thrombolytic therapy."

In the study, most patients with blockage in a proximal artery, close to the base of the brain, continued to demonstrate a diffusion-perfusion mismatch between nine and 24 hours after the onset of their strokes.

"Patients who have a mismatch have been successfully treated up to nine hours after stroke onset, which is already much longer than the guidelines allow, Dr. Copen said. "Our findings suggest a need for a clinical trial to measure the effectiveness of thrombolytic therapy more than nine hours after the onset of an ischemic stroke."

Source: Radiological Society of North America

Explore further: Experts denounce clinical trials of unscientific, 'alternative' medicines

add to favorites email to friend print save as pdf

Related Stories

Water crisis threatens thirsty Sao Paulo

1 hour ago

Sao Paulo is thirsty. A severe drought is hitting Brazil's largest city and thriving economic capital with no end in sight, threatening the municipal water supply to millions of people.

Canada to push Arctic claim in Europe

2 hours ago

Canada's top diplomat will discuss the Arctic with his Scandinavian counterparts in Denmark and Norway next week, it was announced Thursday, a trip that will raise suspicions in Russia.

Google to help boost Greece's tourism industry

2 hours ago

Internet giant Google will offer management courses to 3,000 tourism businesses on the island of Crete as part of an initiative to promote the sector in Greece, industry union Sete said on Thursday.

NKorea launch pad expansion 'nearing completion'

2 hours ago

A U.S. research institute says construction to upgrade North Korea's main rocket launch pad should be completed by fall, allowing Pyongyang (pyuhng-yahng) to conduct a launch by year's end if it decides to do so.

Recommended for you

Obese British man in court fight for surgery

Jul 11, 2011

A British man weighing 22 stone (139 kilograms, 306 pounds) launched a court appeal Monday against a decision to refuse him state-funded obesity surgery because he is not fat enough.

2008 crisis spurred rise in suicides in Europe

Jul 08, 2011

The financial crisis that began to hit Europe in mid-2008 reversed a steady, years-long fall in suicides among people of working age, according to a letter published on Friday by The Lancet.

New food labels dished up to keep Europe healthy

Jul 06, 2011

A groundbreaking deal on compulsory new food labels Wednesday is set to give Europeans clear information on the nutritional and energy content of products, as well as country of origin.

Overweight men have poorer sperm count

Jul 04, 2011

Overweight or obese men, like their female counterparts, have a lower chance of becoming a parent, according to a comparison of sperm quality presented at a European fertility meeting Monday.

User comments : 0