New clue: Brain arteries widen, not clog, in common stroke type

A study suggests a common type of stroke is not caused by blocked arteries, but by their widening. This finding may explain why standard medications often fail as treatment. Lacunar strokes account for one in four strokes in the UK, affecting about 35,000 people each year. For years, doctors believed these strokes resulted from fatty deposits blocking small arteries in the brain. The new research indicates the problem is actually the opposite: the arteries widen. This structural change explains why drugs designed to prevent blockages—such as certain blood thinners—do not work effectively for lacunar strokes. The discovery could lead to new approaches for prevention and treatment.