Earlier diagnosis of Alzheimer s may be possible

Alzheimer's disease remains a virtually untreatable condition, but medical researchers are making strides toward diagnosing it more accurately. The latest, much-anticipated test uses brain imaging to identify the amyloid proteins that are a hallmark of the disease. The test, developed by Eli Lilly, was approved by the FDA on Friday and will be available in June.

The test uses a radioactive agent called florbetapir (Amyvid) to tag clumps of amyloid protein in the brain, which then renders them visible with positron emission tomography otherwise known as a PET scan. The hope is that, when administered to patients who are already experiencing some level of cognitive decline, the test can help to more conclusively diagnose AD. But because about 20 percent of healthy older adults with no indication of the cognitive problems of Alzheimer s have also been found to have amyloid plaques, the test alone should not be used to diagnose the disease.

However, since there is still no effective treatment for Alzheimer's disease, some experts wonder how useful the over-$1,600 test can be. One answer is that, if this new diagnostic technique accurately identifies people at high risk for Alzheimer s, these patients can be enrolled in therapeutic trials that may ultimately speed research to find effective treatments, particularly those that target patients at an earlier stage of the disease. The test could also allow doctors to track the progression of the disease in the brain. And, on a more pragmatic level, there are people for whom a more accurate method of diagnosis means extra time to come to terms with the inevitable progression of the disease, and to plan.

ACSH's Dr. Josh Bloom believes that this new method of diagnosis is important. "If this test is shown to reliably predict Alzheimer s risk, then, for the first time," he says, "doctors will be able to diagnose this condition on a neurophysiological, instead of on a solely behavioral, level. It will make conducting clinical trials feasible, which should provide a path toward finding effective drugs against the disease."