The irony is that while restoration of blood flow is a prerequisite for recovery, sometimes this restoration, if it occurs into already damaged tissue, can paradoxically make things worse and thereby antagonize the benefit that the patient may have otherwise enjoyed, says Michael A. De Georgia, M.D., co-principal investigator and head of the Neurological Intensive Care Program at The Cleveland Clinic Foundation.
De Georgia and colleagues found that inducing moderate hypothermia after a stroke is feasible and safe. Preliminary results of this study, which researchers call COOL AID (COOLing for Acute Ischemic Brain Damage) were presented at the American Stroke Associations 26th International Stroke Conference in February.
Some individuals are severely disabled by strokes partly because they have irreversibly damaged brain tissue by the time they arrive at the hospital. Clot-busting drugs can restore blood flow and limit tissue damage if delivered within three hours of stroke symptom onset. Yet, sometimes restoring blood flow causes more tissue damage known as reperfusion injury. This injury occurs when the rush of restored blood flow causes more insult to already injured tissue. Some experiments have indicated that hypothermia (lowered body temperature) can suppress the release of oxygen free radicals and inflammatory responses known to play a role in reperfusion injury.
The goal of this pilot study was to provide brain protection to patients at high risk of developing large strokes by combining strategies to restore blood flow with hypothermia. After clot-busting drugs showed little or no improvement, researchers induced s
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Contact: Carole Bullock
caroleb@heart.org
214-706-1279
American Heart Association
2-Aug-2001