A new study has suggested that one of the most common forms of stroke may not be mainly caused by blocked arteries, challenging long-standing medical beliefs about stroke prevention and treatment.
Researchers found that lacunar stroke a type of ischemic stroke that affects the deep parts of the brain may instead be linked to damage and widening of tiny blood vessels inside the brain.
The findings, published in the medical journal Circulation, showed that narrowing of large arteries was not strongly connected to lacunar stroke or cerebral small vessel disease, a condition that damages the brain’s smaller blood vessels.
Scientists examined 229 stroke patients in Edinburgh, United Kingdom, between 2018 and 2021. Among them, 131 had suffered lacunar strokes, while others experienced mild non-lacunar strokes.
Patients underwent MRI brain scans and medical assessments at the start of the study and again one year later. Researchers compared changes in the blood vessels with stroke types and overall brain health.
The study discovered that patients with widened and elongated small brain arteries were nearly four times more likely to have experienced lacunar strokes.
Researchers also found strong links between these vessel changes and cerebral small vessel disease, including a higher risk of silent strokes small areas of brain damage that often occur without noticeable symptoms.
More than one-quarter of the participants developed silent strokes within a year, despite receiving standard stroke prevention treatments such as blood pressure medication, cholesterol-lowering drugs, and antiplatelet medicines like aspirin.
Lead researcher Joanna Wardlaw said the findings suggest that lacunar stroke is more closely related to disease in the brain’s tiny blood vessels than to fatty blockages in larger arteries.
According to the researchers, this may explain why common stroke prevention drugs are often less effective for patients with lacunar stroke.
The team believes widening of arteries could reflect weakening in blood vessel walls, reducing their ability to properly regulate blood flow in the brain.
Experts say the findings may push future treatments toward improving the health and function of small brain vessels instead of focusing mainly on preventing artery blockages.
Researchers are now carrying out the LACunar Intervention Trial 3, also known as LACI-3, to test whether existing cardiovascular drugs can better protect the brain’s small blood vessels and reduce the risk of future strokes and cognitive decline.
