The Times Herald (Norristown, PA)
Under the microscope
other symptoms. About onethird of people over 70 who show no thinking problems actually have brain signs that suggest Alzheimer’s, Jack said.
There is no cure — current medicines such as Aricept and Namenda just temporarily ease symptoms. Dozens of hoped-for treatments have failed, and doctors think one reason may be that the studies enrolled patients after too much brain damage had already occurred.
“By the time that you have the diagnosis of the disease, it’s very late,” said Dr. Eliezer Masliah, neuroscience chief at the Institute on Aging.
“What we’ve realized is that you have to go earlier and ear- lier and earlier,” just as doctors found with treating cancer, he said.
Another problem: as many treatment might help, and the as 30 percent of people en- new definition aims to improve rolled in Alzheimer’s studies patient selection by using brain based on symptoms didn’t ac- scans and other tests. tually have the disease — they had other forms of dementia or even other medical conditions. That doesn’t give an accurate picture of whether a potential
BETTER TESTS
Many other diseases, such as diabetes, already are defined by measuring a biomarker, an objective indicator such as blood sugar. That wasn’t possible for Alzheimer’s disease until a few years ago, when brain scans and spinal fluid tests were developed to do this.
They measure certain forms of two proteins — amyloid and tau — that form plaques and tangles in the brain — and signs of nerve injury, degeneration and brain shrinkage.
The guidelines spell out use of these biomarkers over a spectrum of mental decline, starting with early brain changes, through mild impairment and Alzheimer’s dementia.
WHAT TO DO?
People may be worried and want these tests for themselves or a family member now, but Jack advises: “Don’t bother. There’s no proven treatment yet.”
You might find a doctor willing to order them, but spinal fluid tests are somewhat invasive, and brain scans can cost up to $6,000. Insurance usually does not pay because they’re considered experimental outside of research. A large study is underway now to see whether Medicare should cover them and when.
Anyone with symptoms or family history of dementia, or even healthy people concerned about the risk can consider enrolling in one of the many studies underway.
“We need more people in this pre-symptomatic stage” to see if treatments can help stave off decline, Masliah said. Marilynn Marchione can be followed on Twitter at http:// twitter.com/MMarchioneAP The Associated Press Health & Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.