Stroke is one of the leading causes of disability and death around the world. While many people know that blocked arteries can trigger a stroke, scientists are learning that not every stroke develops in the same way.
A new study suggests that one common type of stroke may have a very different cause than doctors have believed for many years.
The research was carried out by scientists from the University of Edinburgh, the UK Dementia Research Institute and international collaborators. Their findings were published in the journal Circulation. The results could help explain why standard stroke prevention medicines do not always work well for people with lacunar stroke.
Lacunar ischemic stroke develops when the brain’s smallest blood vessels become damaged. It is closely linked with cerebral small vessel disease, which can also contribute to memory loss, dementia, walking problems and repeated strokes. Because these tiny vessels are difficult to study, researchers have struggled to understand exactly what causes the disease.
For many years, experts suspected that fatty plaque narrowing larger arteries played a major role. Medicines such as aspirin and other antiplatelet drugs are commonly used to reduce clot formation in larger blood vessels. However, these treatments have shown only limited success in preventing lacunar stroke.
To investigate further, researchers studied 229 people who had experienced either a lacunar stroke or another mild type of stroke. Participants underwent brain MRI scans soon after their stroke and again one year later. The team also assessed their health and thinking abilities throughout the study.
The researchers compared two possible explanations. One was narrowing of larger arteries caused by fatty deposits. The other was enlargement and widening of arteries inside the brain, which may reflect damage to the small blood vessels.
The results clearly favoured the second explanation. Narrowing of larger arteries was not linked with lacunar stroke or worsening small vessel disease. In contrast, enlarged arteries were strongly associated with lacunar stroke, more severe small vessel disease and a much higher chance of developing additional silent strokes.
Silent strokes are small areas of brain injury that often cause no immediate symptoms. Even so, they can gradually damage memory, thinking and movement. More than one-quarter of the participants developed new silent strokes during the study despite receiving standard preventive treatment.
These findings are already influencing new research. Clinical studies such as the LACI-3 trial are investigating medicines including cilostazol and isosorbide mononitrate, which aim to protect the brain’s smallest blood vessels rather than focusing mainly on larger arteries.
This study is important because it challenges a long-standing theory about how lacunar stroke develops. Its strengths include detailed MRI scans and one-year follow-up, but larger studies will still be needed to confirm the findings and determine which new treatments work best.
If confirmed, the research could lead to more effective therapies that reduce future strokes, disability and dementia.
If you care about stroke, please read studies about how to eat to prevent stroke, and diets high in flavonoids could help reduce stroke risk.
For more health information, please see recent studies about how Mediterranean diet could protect your brain health, and wild blueberries can benefit your heart and brain.
Source: University of Edinburgh.
