Researchers have identified a potential cause of a common type of stroke that could help explain why standard treatments are often ineffective and open the door to new therapies. The study focuses on lacunar strokes, which affect around 35,000 people in the UK each year and account for roughly one in five of all strokes. They occur when small blood vessels deep within the brain become damaged, leading to problems with memory, thinking, movement and in some cases, dementia.
Unlike ischaemic strokes, which are typically caused by a blocked artery, researchers now believe lacunar strokes may instead be linked to the widening of arteries in the brain. Until now, treatment has largely focused on approaches used for other types of stroke, such as drugs designed to prevent blood clots. But experts say these may not be tackling the underlying cause.
Study Details and Key Findings
The study, carried out by experts at the University of Edinburgh and the UK Dementia Research Institute, involved 229 patients who had experienced either a lacunar stroke or a mild non-lacunar stroke. Participants underwent brain scans and cognitive tests at the time of their stroke and again one year later. Researchers tracked stroke causes, signs of small vessel disease and the development of new brain damage.
The analysis found no link between lacunar stroke and the narrowing of large arteries. Instead, it showed a clear association with widened arteries in the brain. Patients with widened arteries were found to be four times more likely to experience a lacunar stroke, according to the results.
Implications for Treatment
Researchers say this could help explain why commonly used treatments, such as anti-platelet drugs designed to prevent blood clots, are often less effective in this group of patients. The study also found widened arteries were linked to a higher risk of so-called 'silent strokes', which occur without obvious symptoms. More than one in four participants experienced silent strokes during the study period, despite receiving preventative treatment.
The British Heart Foundation estimates that lacunar strokes account for around one in five strokes in the UK - roughly 35,000 cases annually. Experts are now calling for targeted treatments that address damage to the brain’s small blood vessels rather than focusing solely on larger arteries.
Expert Commentary
Professor Joanna Wardlaw of the University of Edinburgh’s Institute for Neuroscience and Cardiovascular Disease and the UK Dementia Research Institute said: “This study provides strong evidence that lacunar stroke is not caused by fatty blockage of larger arteries, but by disease of the small vessels within the brain itself. Recognising this distinction is crucial, because it explains why conventional treatments like anti-platelet drugs are not as effective for this type of stroke and highlights the urgent need to develop new therapies that target the underlying microvascular damage.”
The findings, published in the journal Circulation, are already informing further research into potential treatments, including the LACunar Intervention Trial 3 (LACI-3), which is testing whether existing drugs could be repurposed to treat the condition.
