"No one wants to hear that he or she has Alzheimers disease. But if the betaamyloid plaques that are the disorders key physical hallmark could be detected before memory loss and cognitive troubles were evident to all would you want to know And since no treatment currently works to stem the inexorable progress ofAlzheimers who would pay for a costly test to detect it early  and why Those questions are no longer hypothetical. Last week the FDA approved  http agent called Florbetapir F  injection to be marketed as Amyvid which will allow physicians using a positron emissions tomography PET scan to detect the presence and extent of amyloid plaques in patients concerned about declining mental function. And on Monday the American Academy of Neurology released a new study showing that an agent called florbetaben also allowed detection of amyloid plaques when used with a PET scan. The florbetaben study http is to be presented at the academys Emerging Science program next week in New Orleans. Both Florbetapir F  and florbetaben help diagnose Alzheimers by sticking to beta amyloid clumps and emitting radioactivity which can then be picked up by a PET scan. Until recently the diagnosis of Alzheimers disease could be made only after a patients death when a pathologist could find physical evidence of amyloid plaques and neurofibrillary tangles. A brain biopsy now can be used to detect Alzheimers plaques but is highly invasive and may miss parts of the brain where the plaques and tangles of Alzheimers are densest. While diagnosis by proton magnetic resonance spectroscopy is under study for early detection httparticles.latimes.comaugnewslahebalzheimersdiagnosis accurate early detection by such noninvasive means is a ways away.   The FDA says that Amyvid is not a test to predict the development of ADassociated dementia in those who have no problematic symptoms. Its an early test for those who already have cognitive concerns and who wonder whether Alzheimers disease may be the cause. Among patients diagnosed with mild cognitive impairment about  have amyloid plaques and will go on to develop dementia that is likely Alzheimers disease said Dr. Michael W. Weiner of the Department of Veterans Affairs Center for Imaging of Neurodegenerative Diseases. Weiner is the leading researcher on the largest and most comprehensive Alzheimers research initiative of its kind the Alzheimers Disease Neuroimaging Initiative httpadniinfo.org. ADNI a nationwide consortium that is still enrolling subjects is a fiveyear million project that will track  participants to compare how mental and dailylife skills and the brains structure and function change in those aging normally those with mild cognitive impairment and those with dementia. Weiner conducted much of the research leading to Amyvids approval. For now says Weiner there is no consensus on which patients should get the costly new PET scans that use Amyvid and large insurers such as Medicare and Medicaid have not made decisions about coverage for such tests. And some patients may question whether they would want to know that the source of their mental troubles is Alzheimers disease said Weiner. But for many when you take a person to the doctor you usually want an answer whether it leads to a treatment or not. This is a way of getting closer to an answer said Weiner. Many patients experiencing cognitive lapses may also be reassured if the test fails to reveal amyloid plaques he added. With growing understanding that the changes of Alzheimers disease may be decades in the making the value of early detection is gaining adherents said Weiner. The real gamechanger he says will be when one of the many experimental therapies under study for Alzheimers disease succeeds in blocking or reversing its progress. Once that happens physicians researchers and insurers will need to figure out who should get the test and at what cost and who will pay."