"The patient turned  over the summer and was already having symptoms that made her neurologist wonder whether she had Alzheimers disease the deadly mindkilling dementia that usually attacks far older people. She and her husband went to the Adler Institute for Advanced Imaging in Jenkintown on a recent morning after  tests over the last year failed to explain her worsening symptoms. She was going to try yet another a newly approved test developed by a Philadelphia biotech firm. It uses a PET scanner and a radioactive tracer  Amyvid  that binds to amyloid one of the hallmark proteins that accumulate in the brains of Alzheimers patients. Until recently the only sure way to know whether people had Alzheimers was to examine their brains after death. The Food and Drug Administration approved the test in April. It is both a sign of the future of dementia treatment  enabling doctors to identify people at risk for a dread disease even before they have symptoms  and an example of the challenging economic and medical issues new technology so often raises. The test is costly and possibly confusing. There is now no good longterm Alzheimers treatment. The diagnosis could subject patients to discrimination by employers and insurers let alone intense anxiety. Claudia Kawas a geriatric neurologist at the University of California Irvine said a patient strode into her office soon after the FDA approved the procedure and asked for the Alzheimers test. In one hand he held an article about the approval of Amyvid. In the other he had a document from a righttodie group. If the test was positive he told her he would get his affairs in order and kill himself within  days. Although she thinks the test can be useful she was glad her center didnt have it. She says she wouldnt have it done on herself though shes noticing some memory changes. The information I think wouldnt help me in any way she said. The Adler patient who asked that her name not be used is a former college English major who is having trouble finding words thinking clearly and understanding even slightly complicated reading material. On a recent shopping excursion her sister found her wandering aimlessly. Shes having memory spatial and balance problems and has given up driving. Alzheimers would be unusual at her age but an earlier PET scan showed a pattern suggestive of the disease. The new test would support that diagnosis or rule it out. The patient and her husband who met on her st birthday and became engaged six weeks later want to know what to tell their children how to face their future however bleak it may be. Still the woman hoped their search for a diagnosis would not end with this test. Alzheimers at this age is a pretty scary endeavor. Radiologist Lee Adler told her the test which combines a CT and PET scan would take about  minutes. She had to lie perfectly still on a table her head immobile between two wedges. It would be quiet. Adler who began doing the test as part of research in  told her the absence of amyloid would mean she didnt have Alzheimers. Its presence is more complicated. Some people with amyloid in their brains think normally. Some may be at higher risk for Alzheimers but its too soon to know whether amyloid is a sign of what experts are calling preclinical disease. Patients with mild cognitive impairment often a precursor to dementia along with amyloid deposits may be at higher risk. We can exclude the diagnosis Adler said but not make it. The woman climbed onto the scanner and waited for the test to begin. Rajan Agarwal an Abington Memorial Hospital radiologist did the countrys first three commercial Amyvid scans in June and has had no referrals since. Adler also has done three. Though doctors think the test can be a blockbuster PETNET a Siemens subsidiary that distributes the tracer said it had made  commercial doses for this region since June. The tracer is made individually for each patient on test day at  sites around the country then delivered within a hour radius. In this region its mixed in North Wales. Lack of coverage for the  test is the biggest barrier to it here. Medicares decision on coverage which often sets the standard for private insurers is due by July. Doctors dont know what causes Alzheimers. Amyloid and tau in the brain are the proteins that define the diagnosis but its still unclear whether amyloid causes symptoms or defends against the disease. Drugs that target it have been disappointing so far. Doctors say Amyvid is likely to be most useful when people have symptoms but the diagnosis is uncertain. It would help doctors decide between say Alzheimers and frontotemporal dementia. Negative Amyvid results can spur doctors to seek other explanations and avoid prescribing useless drugs that have side effects. Recent studies involving Amyvid which is made by Avid Radiopharmaceuticals an Eli Lilly  Co. subsidiary have shown that a surprising number of patients thought to have Alzheimers didnt. A paper in the October issue of Annals of Neurology noted that  of  patients diagnosed with Alzheimers by expert physicians had negative PET scans for amyloid. One emerging lesson said Jason Karlawish an Alzheimers expert at the University of Pennsylvania is that Alzheimers may be more than one disease or variant. In an article published in the fall in the journal Alzheimers  Dementia a group of international experts who gathered at Penn over the summer said other biomarkers were being tested in clinical trials from imaging compounds to analyses of blood and cerebrospinal fluid. Laws prohibiting the use of biomarkers in insurance or employment decisions may also be in order until their clinical value is fully understood they said. For now one of the most obvious benefits of biomarkers is that they can help researchers put patients in the right clinical trials. That raises the odds that a drug meant to treat Alzheimers is being tested on people with the disease. Dementia experts know changes associated with Alzheimers begin decades before its diagnosed. When there is a treatment it almost certainly will make sense to start early before the disease causes extensive brain damage. Then demand for tests like Amyvid will skyrocket. The race is on here between the biomarkers and the therapeutics said Rise Sperling a Harvard University Alzheimers expert. In Jenkintown Adlers patient emerged from her scan. It was lovely she said. Adler told the couple he could see that the womans brain had not atrophied. Good news. Later the patient who did not want her name used until she knows whats wrong with her learned the test had been negative. Shes left with the mystery but glad to rule out Alzheimers. Its actually a relief she said because that would have been the worstcase scenario."