Genetic Clues to ‘Silent Strokes’ Uncovered
After years of research, scientists have uncovered genetic clues to ‘silent strokes’, a major cause of vascular dementia, opening up new pathways to prevention and treatment.
Lacunar strokes are caused by the weakening of the walls of small blood vessels in the brain that can be only a millimetre in diameter. Such strokes by these can often happen in a stepwise progression, only to be detected when symptoms are noticeable and damage has been done. Few drugs are available to prevent or treat these kinds of strokes.
Thus far, only one genetic fault has been linked to lacunar strokes. Professor Hugh Markus, BHF-funded researcher and neurologist at the University of Cambridge led a study working with researchers around the world to investigate the genetics behind lacunar strokes. They believe their breakthrough can yield treatments for lacunar stroke and vascular dementia.
Recruiting participants from around the world after they attended hospital and had an MRI or CT brain scan., the researchers scanned and compared the genetic code of 7338 patients who had a lacunar stroke with 254 798 people who had not. They found 12 genetic regions associated with lacunar strokes
The researchers found that these 12 genetic regions are linked to vascular control, and dysfunctions make the blood-brain barrier more permeable to toxins, and messages sent around the brain slow down or fail to arrive completely.
“These small and often silent lacunar strokes have gone under the radar for a long time, and so we haven’t been able treat patients as well as we’d like to,” said study leader Prof Hugh Markus. “Although small, their consequences for patients can be enormous. They cause a quarter of all strokes and they are the type of stroke which is most likely to lead to vascular dementia.
“We now plan to use this new genetic blueprint as a springboard to develop much needed treatments to prevent lacunar strokes from occurring in the first place and to help stave off dementia.”
First author Dr Matthew Traylor, of the study at Queen Mary University of London, said: “Genetics offers one of the few ways we can discover completely new insights into what causes a disease such as lacunar stroke. It is only by better understanding of what causes the disease that we will be able to develop better treatments.”
Professor Sir Nilesh Samani, Medical Director at the British Heart Foundation and cardiologist, said: “This is the most extensive genetic search to date which truly gets to grips with what cause lacunar strokes. These findings are a significant leap forward and we now have a much greater understanding of the genetics and biology behind what causes the small blood vessels deep in the brain to become diseased.
“Lacunar strokes affect around 35 000 people in the UK each year. This research provides real hope that we can prevent and treat this devastating type of stroke much better in the future.”
Source: Medical Xpress
Journal information: The Lancet Neurology (2021). DOI: 10.1016/S1474-4422(21)00031-4
