A need to know: Is it Alzheimer’s?

For almost three years, Janelle Lafser pleaded with doctors to order a PET scan for her husband, Frank.

He had been experiencing memory and mood problems -- beginning at age 45 -- and was having trouble in his job as an executive at a paint company. The doctors said he was depressed, but Janelle was unconvinced.

She told them that her husband forgot plans the couple had made, misplaced things and found paying bills too confusing. She suspected Alzheimer’s disease and wanted the positive emission tomography test because it can provide physical evidence of the disease.

Physicians steadfastly refused, telling her that Frank was too young to have Alzheimer’s, which occurs mostly in people age 65 and older. “I think you want that diagnosis,” an exasperated neurologist told Janelle one day when she again requested a PET scan to look for Alzheimer’s.

“I want the truth,” she snapped back.

Finally, when his doctors recommended electric shock treatments for depression, Janelle made it contingent upon a PET scan that showed no abnormalities. Only then did the Lafsers, who live in La Quinta, get the scan. As Janelle suspected, Frank had Alzheimer’s disease.

Until recently, PET scanning has been seldom used in the diagnosis and treatment of Alzheimer’s, even though it is billed as “a window to the brain” and is the only test, other than an autopsy, to offer physical proof of the disease. At about $1,500 per exam, doctors have deemed it too expensive and too experimental, with many saying a scan would be of little practical benefit to a patient with an incurable disease.

But some families have increasingly countered that they need a specific diagnosis of Alzheimer’s -- backed by a PET scan -- to ensure proper treatment and to plan for their loved ones’ gradual deterioration.

Now, more of them will know what type of treatment to pursue and whether to make long-term arrangements. In October, Medicare announced that it would begin to pay for PET scans in some patients with signs of the disease, a move that is expected to lead to increased coverage by private insurers as well.

That move could be just the beginning. Many experts predict that, within the next decade, PET scanning also may be recommended for healthy people who lack symptoms but who are at high risk for developing the disease. For these people, the tests may determine whether their brains are already exhibiting signs of degeneration.

Alzheimer’s physicians and researchers say PET scanning will lead to better diagnoses in the short term and -- with other brain-imaging techniques and blood tests in development -- to preventive treatment of Alzheimer’s in the long term.

“PET scanning is going to be a very powerful tool in the future,” says Dr. Richard Powers, a trustee of the Alzheimer’s Foundation of America and chief of the bureau of general psychiatry for the Alabama Department of Mental Health. “The problem with Alzheimer’s treatment right now is we are waiting until folks are so demented before diagnosing them that the treatments are not as effective as they are when you give them early.”

Alzheimer’s disease is a progressive brain disorder that causes declines in memory, cognition and functioning. About 10% of Americans over age 65 and half of all people over age 85 have the disease, according to the Alzheimer’s Assn. No one knows what causes Alzheimer’s, although most researchers believe there are genetic influences.

PET produces images of the brain’s activity; most other imaging devices only show structures in the brain. During a PET scan, a radioactive substance is injected into the body and a scanner tracks the resulting signals. The procedure is considered extremely safe because only a small amount of radiation is required.

Currently, the vast majority of people with Alzheimer’s disease don’t undergo the scans, says Robert J. Schumacher, vice president of the western region for Molecular Imaging Corp., a major provider of PET services, based in San Diego. Most are diagnosed after a comprehensive work-up that essentially rules out other causes of dementia. This approach includes a physical exam, lab tests and extensive psychological and cognitive tests.

“The pioneers have been using PET for Alzheimer’s for about 10 years,” says Schumacher. “But, as far as across the board, most people don’t know this tool is out there.”

The traditional office assessment for Alzheimer’s disease can take months or years and is less accurate than PET scanning, advocates of the scan say.

Widely accepted research shows that traditional methods diagnose Alzheimer’s accurately only 60% to 70% of the time, said Dr. Daniel Silverman, director of the UCLA Alzheimer’s Disease Center, Imaging Core. PET scanning, meanwhile, is about 91% accurate, he says.

The use of PET varies widely among doctors and medical centers. Patients or their families with financial or educational resources tend to request PET scans and pay out-of-pocket, while the average, elderly person with memory problems knows nothing of the technology or can’t afford it, says Dr. Peter Conti, director of the PET center at USC and president-elect of the Society of Nuclear Medicine.

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Limited coverage

In ruling that it would pay for PET scans for some people suspected of having Alzheimer’s, the Centers for Medicare and Medicaid Services stopped short of endorsing the scans as a general diagnostic test for the disease. Instead, Medicare and Medicaid will only cover the test for those patients whose symptoms are not typical and who doctors believe may have either Alzheimer’s disease or one of several other brain disorders known as fronto-temporal dementia.

But it’s a significant first step, says Dr. William Bradley Jr., chairman of the department of radiology at UC San Diego.

“It’s a big deal that CMS decided to cover it,” Bradley says. “If you can use diagnostic imaging equipment like PET earlier and either slow a disease or cure it altogether, that is going to save money in the long run.”

Currently, experts agree that the best use for PET in the Alzheimer’s arena is to help doctors figure out if a patient has the disease when the standard work-up has not produced a clear answer. A scan would be of little use to a 90-year-old who is in a nursing home and hasn’t been able to recall her name for several years, they say. Nor should it be a screening device to assess every nervous baby boomer who suddenly can’t recall his kids’ birthdays.

“We don’t want people every time they forget where their keys are to come in and get a PET scan,” says Conti.

But for many patients, an earlier diagnosis offers several advantages, says Silverman, such as the opportunity to take one of several medications for Alzheimer’s disease. The drugs typically work better the earlier they are started. Approved medications for Alzheimer’s can help to temporarily improve symptoms and slow progression of the disease.

“There is no question PET improves the accuracy of the diagnosis,” Silverman says. “What the data show is that you not only make an accurate diagnosis, but you make that accurate diagnosis three years ahead of time.”

Some leaders in the field suggest that PET scanning could eventually be used to follow the progression of the disease and assess whether medications are working. And, although current drugs can only do so much, an earlier diagnosis can help families plan for the future, Conti says.

The Lafsers found Frank’s diagnosis both devastating and a relief.

“Once we knew the answer, all of my anger went away,” says Janelle. “I could love him and accept that this is where we’re going now. For Frank, it was like a ton of bricks was lifted off his shoulders. He had been beating himself up about why he was acting this way.”

Families afflicted by Alzheimer’s disease need to confront the disease as soon as possible, says Eric J. Hall, chief executive of the Alzheimer’s Foundation of America. The group encourages widespread screening for the disease, including PET scanning when indicated.

“There is a deep-seated fear of this disease. You end up with a situation in which people wait too long to be diagnosed,” Hall says. “The people who call us are already in crisis and chaos. If there is a way to assist individuals and their families in easing the burden through earlier diagnosis, then that is something we should do.”

But another powerful patients’ group, the Alzheimer’s Assn., fears that PET scanning may be aggressively marketed as a general test for Alzheimer’s.

“While the imaging technologies are all very exciting and certainly hold the promise of acting earlier and earlier in the disease progress, we aren’t there yet,” says Bill Thies, vice president of medical and scientific affairs at the Alzheimer’s Assn. He says not enough is known about how widespread use of PET scans for diagnosing Alzheimer’s would help all patients or whether such a strategy would be cost-effective.

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Nationwide study

Researchers acknowledge they have much to learn about PET scans and Alzheimer’s disease.

In its recent announcement, the Medicare agency said it would also cover PET scans for patients with suspected Alzheimer’s who participate in a nationwide study, coordinated through the National Institute on Aging, to clarify the central questions in the PET-Alzheimer’s debate. Among them: How is the technology useful for people early in the course of the disease?

In addition, the National Institute on Aging announced in October plans for a five-year study on how PET, MRI and biological markers, such as blood and cerebral spinal fluid, can be combined to measure the progression of mild cognitive impairment and Alzheimer’s disease.

Other researchers are also studying how PET can be used to assess progression of the disease. A study published last year by Silverman and his colleagues showed that PET scanning in patients with mild cognitive complaints could be used to predict the patients’ future cognitive decline or stability, thus helping doctors decide on treatments, and helping families to plan.

Still other doctors are studying families with a strong incidence of the disease to see if PET scanning can reveal changes in the brain well before any symptoms occur. This knowledge could lead to drugs that disrupt the disease process, says the Alzheimer’s Assn.’s Thies. And a few scientists are using different imaging agents to detect the development of amyloid plaques -- protein deposits that disrupt brain cell function and that may be one of the primary causes of the disease.

All agree that people with Alzheimer’s will increasingly benefit from technology that reveals --objectively -- what is happening in the brain.

“Now we have a way of following the disease,” says UC San Diego’s Bradley. “That will spur the development of additional drugs. We do have a chance to cure this disease in some way. But we need an accurate way of imaging it first.”