Scientists have uncovered the cause of one of the most common types of stroke, in a breakthrough that could change the understanding of current treatment methods and explain the limited effectiveness of some drugs used.
A new study shows that ischemic strokes ( a type of stroke), which account for about a quarter of all strokes, may not be caused by the buildup of fatty deposits in the arteries as previously thought, but by a different problem related to the dilation of tiny arteries within the brain.
Researchers from the University of Edinburgh say this type of stroke is actually linked to a disease that affects small blood vessels, causing them to become damaged and deteriorate over time, which may explain why many patients do not respond to traditional treatments such as aspirin and anticoagulants.
The study, published in the medical journal Circulation, followed 229 patients who had experienced a coma or a minor non-coma stroke, who underwent brain scans and clinical tests immediately after the injury, and were then reassessed a year later to monitor changes.
The results showed that narrowing of the arteries caused by fatty deposits is not associated with ischemic strokes, while dilation of the arteries was a clearly associated marker with this type of stroke, with the risk of stroke increasing more than fourfold in those who exhibited this characteristic.
The researchers suggest that this expansion may be a result of small vessel disease, which leads to gradual damage to the tiny blood vessels within the brain.
The team concludes that understanding leukocortic strokes should move in the future towards studying and treating this damage to the microvasculature, rather than focusing solely on preventing blood clots.
Professor Joanna Wardlow, a brain imaging and heart disease specialist and the lead author of the study, explains that the findings provide strong evidence that ischemic stroke is not caused by a blockage in the large arteries due to fat, but rather by a malfunction in the small vessels within the brain itself.
She adds that understanding this difference is very important, because it explains the limited effectiveness of current treatments that focus on preventing blood clots, and underscores the need to develop new treatments that directly target damage to microvascular blood vessels.
A stroke generally occurs when blood flow to a part of the brain is interrupted by a blockage or bleeding, leading to damage to brain cells.
The main risk factors include high blood pressure, smoking, high cholesterol, diabetes and obesity, while prevention usually relies on drugs that prevent the formation of clots, such as aspirin.
