[ad_1]
Alzheimer’s silently destroys the brain long before symptoms appear and now scientists have new clues about the key sequence of those changes – a potential window for one day intervention. A large study in China tracked middle-aged and older adults for 20 years using routine brain scans, spinal taps and other tests. Compared with people who remained cognitively healthy, people who eventually developed the brain-destroying disease had higher levels of an Alzheimer’s-associated protein in their spinal fluid 18 years before diagnosis, researchers reported Wednesday. . Then every few years, studies revealed another so-called biomarker of the growing problem.
Scientists don’t know exactly how Alzheimer’s develops. An early hallmark is a sticky protein called beta-amyloid, which turns into plaques that clog the brain over time. Amyloid alone isn’t enough to cause memory damage—many healthy people have large amounts of plaque deposited in their brains. An abnormal tau protein that forms neuron-killing tangles is one of several co-conspirators. (Also read: Research suggests common gut bacteria may increase risk of Alzheimer’s disease ,
The new research, published in the New England Journal of Medicine, provides a timeline of how those abnormalities stack up. Dr. Richard Mayeux, an Alzheimer’s expert at Columbia University who was not involved in the research, said the importance of the study “cannot be overstated.”
“Knowledge of the timing of these physiological events is critical” to testing new methods of treatment and ultimately preventing Alzheimer’s, they wrote in an editorial. The findings have no practical implications yet.
More than 6 million Americans and millions more worldwide have Alzheimer’s, the most common form of dementia. there is no cure. But last year a drug called Lecambi was approved for the first time with clear evidence that it could slow early Alzheimer’s disease — even if only by a few months.
It works by clearing out some of that nasty amyloid protein. The approach is also being tested to see if it’s possible to delay the onset of Alzheimer’s if high-risk people are treated before symptoms appear. There are still other drugs being developed to target tau.
Tracking silent brain changes is important for such research. Scientists already knew that in rare, inherited forms of Alzheimer’s, which affect young people, a toxic form of amyloid begins to accumulate about two decades before symptoms and at some point later leads to tau. It starts. The new findings show the order in which such biomarker changes occur as aging becomes more common with Alzheimer’s.
Researchers at Beijing’s Innovation Center for Neurological Disorders ultimately compared 648 people with Alzheimer’s and a similar number of healthy people. Depending on the test used, amyloid was discovered in future Alzheimer’s patients either 18 years or 14 years before diagnosis.
Differences in tau were discovered, which then led to problems in communication between neurons. The study found that a few years later, differences in brain shrinkage and cognitive test scores between the two groups became apparent.
“The more we know about viable Alzheimer’s treatment targets and when to address them, the better and faster we will be able to develop new therapies and preventions,” said Claire Sexton, senior director of scientific programs for the Alzheimer’s Association. He said blood tests are coming soon that promise to help by making amyloid and tau easier to track.
[ad_2]
