Bat-Spit Drug May Improve Stroke Recovery
Drug Made From Vampire Bat Saliva Extends Stroke Treatment Window
In this study, patients were selected using a new magnetic resonance imaging (MRI) technique called diffusion-perfusion mismatch. The technique can show the area of brain damage that cannot be reversed and the area that is not yet damaged but is at risk hours after the stroke.
Warach says patients with at least 20% of brain cells in the "at-risk" area are good candidates for treatment, but "the larger the at-risk area, the better the results." Asked if the same technique could be used to select patients for tPA, Warach said, "in my opinion, yes."
By repeating MRI scans after treatment with the new clot buster, the researchers were able to show that treatment restored blood flow. The return of blood flow, to areas considered to be at risk for irreversible damage, correlated with how well stroke victims did after treatment.
Howard Rowley MD, associate professor of radiology at the University of Wisconsin Medical School and lead radiologist for the study, says the "new MRI techniques are key in helping to select the right patients for therapy."
Rowley also says that the impact of the expanded treatment window -- 9 hours vs. 3 hours -- "cannot be overstated. Buying more time to treat stroke symptoms -- and the ability to safely restore blood flow to the brain -- means we can give acute stroke victims hope for a better outcome, even if having a stroke cannot be prevented."
Michael Moskowitz, MD, director of the stroke and neurovascular regulation laboratory at Harvard Medical School, says the "three hour window is pretty severe when we are trying to get patients to treatment." He tells WebMD that a drug that can be used "as late as nine hours is extremely promising."
Moskowitz, who led a news conference where Warach presented the results, was not involved in the study.