02/23/2024
Study: Alzheimer’s quietly ravages the brain long before symptoms appear. Scientists now have new clues about the domino-like sequence of those changes.
A large study in China tracked middle-aged and older adults for 20 years, using regular brain scans, spinal taps and other tests. Compared to those who remained cognitively healthy, people who eventually developed the mind-robbing disease had higher levels of an Alzheimer's-linked protein in their spinal fluid 18 years prior to diagnosis. Then every few years afterward, the study detected another so-called biomarker of impending trouble.
Scientists don’t know exactly how Alzheimer’s forms. One early hallmark is that sticky protein called beta-amyloid, which over time builds up into brain-clogging plaques. However, amyloid alone isn’t enough to damage memory, as many people with healthy brains harbor a lot of plaque. The new research offers a timeline for how those abnormalities pile up.
More than 6 million Americans, and millions more worldwide, have Alzheimer’s, the most common form of dementia. While there is no cure for Alzheimer's, last year a drug named Leqembi became the first approved with clear evidence that it could slow the worsening of early Alzheimer’s — albeit for a few months.
Original Article from The New England Journal of Medicine — Biomarker Changes during 20 Years Preceding Alzheimer’s Disease
