The window of opportunity to treat some stroke patients may be longer than three hours, says a new study. Three hours is the standard timeframe that has been referenced in medicine since the 1990s.
Senior author Ashfaq Shuaib at the University of Alberta stated that brain cell death after a stroke may not be complete for hours or even days after a stroke, meaning that stroke victims may have a longer window of opportunity to receive treatment than originally suspected.
According to Shuaib, cell death can be complete within as little as an hour in some people following a stroke, while other patients have viable brain tissue and cells for days or indefinitely after a stroke.
And with current imaging technology, physicians can determine whether brain cells are dead or have simply ceased functioning post-stroke.
"What we're recommending is, don't look at the window of time only, look at the important tissue window which may be quite prolonged in many patients," said Shuaib.
"Don't just say, 'oh this person had a stroke 4.5 hours ago, end of story.' This person may have very good tissue you could treat," he stated.
To come to the conclusion, Shuaib and colleagues at the University of Alberta reviewed stroke studies that examined the use of imaging to measure blood flow in the brain after a stroke.
The literature was written from 1980 to July 2011. His review also notes that using advanced neuroimaging, such as multi-dimensional brain CT scans and MRIs, can provide physicians important information about blood flow in the brain following a stroke.
This information could enable doctors to provide better treatment to prevent brain cells from dying, through the use of techniques to increase blood flow in the brain.
The study was published by University of Alberta medical researchers in Lancet Neurology.