Researchers say they have developed a 100 percent accurate spinal tap test for the brain disease. Brain scans, too, have become a potentially important tool in diagnosing the disease. The new tests are significant because Alzheimer’s can begin more than a decade before symptoms show up and because there is hope that new drugs could be effective.
New York Times:
The new study included more than 300 patients in their 70s, 114 with normal memories, 200 with memory problems and 102 with Alzheimer’s disease. Their spinal fluid was analyzed for amyloid beta, a protein fragment that forms plaques in the brain, and for tau, a protein that accumulates in dead and dying nerve cells in the brain. To avoid bias, the researchers analyzing the data did not know anything about the clinical status of the subjects. Also, the subjects were not told what the tests showed.
Nearly every person with Alzheimer’s had the characteristic spinal fluid protein levels. Nearly three quarters of people with mild cognitive impairment, a memory impediment that can precede Alzheimer’s, had Alzheimer’s-like spinal fluid proteins. And every one of those patients with the proteins developed Alzheimer’s within five years. And about a third of people with normal memories had spinal fluid indicating Alzheimer’s. Researchers suspect that those people will develop memory problems.