Sunday, August 12, 2012

New imaging test lets doctors see Alzheimer’s disease before you do


Posted: Wednesday, June 20, 2012



Over the last year or so, Marigold Thorburn started forgetting things.
Mostly, it was small things. Thorburn, 77, would tell her daughter something. A little while later repeat it, as if it were new information. Her daughter would tell her that she was going to do something, then five or 10 minutes later, Thorburn would ask, what are you doing?

But the forgetting became more frequent, which worried her daughter.
Thorburn underwent some cognitive testing in Jamaica, where she lives, and the United States, where her daughter and son-in-law live, but the results were inconclusive.
Radiologist Dr. Rajan Agarwal prepares a patient for one of the first PET Amyvid scans in the nation
That is until earlier this month when Thorburn was among the first patients in the nation to undergo a new advanced imaging scan that the medical community hopes will lead to a more accurate — and early — diagnosis of Alzheimer’s disease, the most common form of dementia.
But the test has raised concerns among disease activists, including the Alzheimer’s Association, that healthy people could misuse it.
About 5 million Americans have been diagnosed with Alzheimer’s, a progressive neurological disease, and the numbers are expected to soar as Baby Boomers age. But until now, the only way to confirm Alzheimer’s was a brain autopsy or spinal fluid test.
The new Amyvid scan allows doctors, for the first time, to detect plaques of toxic protein called beta-amyloid found in the brains of Alzheimer’s patients. Earlier this year, the federal Food and Drug Administration approved the use of the radioactive agent, which binds to the toxic plaques, for use in brain imaging for patients with cognitive impairment.
Dr. Rajan Agarwal, a radiologist at Abington Memorial Hospital, the first local hospital to offer the scan — which is done using the drug and a positron emissions tomography (PET) scan — called it a significant advance in radiology and nuclear medical testing.
The new scan allows doctors to detect that a person appears at high-risk for developing Alzheimer’s five to 10 years before the symptoms appear, Agarwal said. A moderate to large amount of beta-amyloid deposits is consistent with an Alzheimer’s brain.
For decades doctors have diagnosed Alzheimer’s using a combination of neurological and psychological tests, family history and physical exam, but the guidelines are not definitive. Scientists have found that an estimate 20 percent of people who had a clinical diagnosis of Alzheimer’s didn’t have significant deposits of beta-amyloid present at autopsy.
While the new PET scan is considered a dramatic improvement over the previous diagnosis guidelines, doctors emphasize it should be used in conjunction with traditional physical and cognitive testing.
A positive scan result means a patient most likely will develop Alzheimer’s, Agarwal added. The same plaque deposits also appear in the brain of patients with normal brain activity with other medical conditions, he said. Patients who experience traumatic brain injury also can show large deposits of beta-amyloid.
The Alzheimer’s Association has concerns about the new test as well.
It worries that people with no symptoms of memory decline will treat the test like a preventive screening tool similar to mammograms and colonoscopies. They fear the reactions of some people who get results that they likely will develop a progressive and incurable disease.
To prevent the misuse of the technology, the association has convened a task force to develop guidelines for the medical community it hopes to unveil later this year, said Claire Day, vice president of constituent service for the Delaware Valley chapter of the Alzheimer’s Association.
“When new tests like this come out, I think people make that conclusion that this must be it, this is the magic bullet or the magic answer,” Day said. “From our perspective, we know there is so much more testing and research that has to come into this.”
But unlike other screening tests, the Amyvid scan may have a limited patient pool.
GREAT INTEREST/LIMITED ACCESS
The test is available only in U.S. markets surrounding 16 manufacturing sites including North Wales in Montgomery County. Amyvid loses more than half of its radioactivity every two hours, so it must be distributed directly to imaging centers from the specialized radiopharmacies where it is produced, according to its manufacturer, Eli Lilly & Co.
The 90-minute imaging test costs $3,200 at Abington Memorial and is not covered under private and public health insurance plans.
But some local health care experts believe that such a diagnostic test could still appeal to the health-conscious Baby Boomer generation, especially those with elderly parents suffering memory decline.
“Alzheimer’s, in particular, has such a stigma and its terrifying to people. You will do anything to mitigate your risk,” said Cindy Joy Margelis, interim chairwoman of the health information management department at Temple University’s College of Health Professions and Social Work. “This is a market that is just ripe for this kind of thing. I can tell you, as an educated consumer, I would get it.”
People pay hundreds, even thousands of dollars out-of-pocket now for gene mapping and other advanced tests to predict the likelihood of cancers and other health issues in an effort to prevent signs for as long as possible, added Craig Holm, senior vice president of Health Strategies and Solutions, a Philadelphia health care consulting firm.
There is little financial risk, but great financial reward, for hospitals that offer the specialized services such as the Amyvid scan, even if few patients use it. Since patients pay out-of-pocket, the money is all profit, Holm said.
The test also could be an attractive marketing tool for suburban hospitals trying to attract technology-savvy patients, Margelis said.
“For the community hospitals, it’s really important for them to be perceived as giving the impression they have access to these types of services, so people don’t automatically go to the U. Penns of the world,” Margelis said.
‘WHEN IT WAS OVER’
From a patient perspective, knowing that you are predisposed to Alzheimer’s could help with future financial planning, she said.
There are other reasons why people might want to undergo the test, even if the results could be life-altering, Abington’s Agarwal said.
If the test is negative, then the person knows Alzheimer’s is unlikely, so doctors can focus on other medical conditions that cause cognitive problems, he said. If the test is positive, it offers the person an opportunity for an early start with life planning and decisions.
As for Marigold Thorburn, she says that when her daughter and son-in-law suggested she undergo the special imaging scan, she thought it was a good idea. She wasn’t worried.
“Until afterward, when it was over,” she said.
Her test results were negative.

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