Burst blood vessels in the brain can lead to Alzheimer’s
Scientists seem to have found a new risk factor for Alzheimer‘s disease: burst blood vessels.
An MRI (International Republic Institute) study experimenting with volunteers found mild problems with thinking and memory in those people who had many burst blood vessels in the hippocampus .
“This is exactly the part of the brain that deals with learning and memory,” says Berislav Zlokovic, senior author of the study and director of the Zylka Neurogenetics Institute at the University of Southern California.
The study also found that such blood vessels in the hippocampus tend to cause problems in every person. But this process is accelerated in people who may develop Alzheimer’s disease or other forms of dementia.
Densely packed glial cells (green) and nerve cells (red) surround a blood vessel to form a barrier that keeps toxins from reaching delicate brain cells.< /p>
The discovery suggests it may be possible to identify people at risk of Alzheimer’s disease by looking inside their blood vessels, said Rod Corriveau, program director at the National Institute of Neurological Disorders and Stroke, which helped fund of scientific research.
The results also suggest that drugs that help the body seal off ruptured blood vessels may delay or prevent Alzheimer or other forms of dementia.
“This research gives patients and their families hope for the future that detecting ruptured blood vessels early will provide an opportunity to stop dementia before it starts,” says Corriveau.
The new study builds on earlier studies of people who have died with Alzheimer. “We’ve looked at brains from autopsies, and it’s quite obvious that there is damage to the blood-brain barrier,” says Zlokovic.
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Blood-brain barrier is a special layer of cells that prevents bacteria and toxins circulating in the bloodstream from mixing with the fluid that surrounds the brain cells. When the layer breaks down, the toxins mix with the fluid that surrounds the brain cells and can damage or kill the cells.
The autopsy study could not show whether the distribution occurred before or after the onset of Alzheimer’s. So Zlokovic and his team used a special kind of MRI to study the minds of more than 60 people.
The group included both healthy people and people with mild cognitive impairment, which is an early sign of Alzheimer disease.
“The finding may help explain why people with atherosclerosis or other blood vessel problems are more likely to develop Alzheimer,” says Corriveau. “There is every reason to think that Alzheimer‘s disease is related to vascular damage”.
The study also shows that amyloid plaques and tangles known as tau are not the only factors that lead to Alzheimer.
“There are probably several different pathways to dementia,” says Corriveau, “including ones that involve ruptured blood vessels.”
Scientists are still working on whether it is possible to repair the damage to the blood-brain barrier. This may be possible with the help of cells known as pericytes, which help keep blood vessels in the brain from leaking.
