New Test Predicts Who Will Get Alzheimer's

When older folks find themselves being forgetful or searching for the right word, many become worried that they may be suffering the early symptoms of Alzheimer's disease.

Now researchers say they have found a group of medical tests that can predict with great accuracy which patients are headed toward Alzheimer's and which are not.

In a paper to be published in the October 25 issue of the journal Neurology, a team of physicians and scientists from the University of California, San Diego School of Medicine and elsewhere describe using a combination of broadly available medical tests to produce a much improved predictive picture of the likelihood of impending Alzheimer's in people with mild cognitive impairment, an intermediate stage between the expected cognitive decline of normal aging and the more pronounced decline of dementia.

“I’m extremely excited about these results,” said neurologist James Brewer, MD, associate professor of radiology and neurosciences and part of the Alzheimer’s Disease Neuroimaging Initiative research team at UC San Diego.

“The good news is that we can partially reassure those folks who are negative on these tests, at least regarding their next three years. We have never been able to do that before. These individuals, despite having a real memory problem, have no greater risk of near-term dementia than a similarly aged healthy person without a memory complaint.”

The tests used in the new Alzheimer's evaluation include magnetic resonance imaging (MRI), cerebrospinal fluid (CSF) and neuropsychological testing. All of these are already widely available.

When combined, the tests showed an extremely accurate prediction rate. In fact, it was almost perfect. None of the individuals who tested negative on all three measures went on to develop Alzheimer's in the three-year follow-up. By comparison, almost 90 percent of individuals who tested positive on all three measures were demented at the end of three years.

Dr. Brewer said the findings will result in a dramatic change in the diagnosis of Alzheimer’s disease.

“Instead of saying, ‘Let’s wait a year and see if this gets worse,’ our neurologists can say, ‘Let’s get a volumetric MRI and check back in a month to see if your complaint is due to neurodegeneration.’ That ability makes a huge difference in how we proceed. Maybe the memory complaint isn’t due to neurodegeneration, but rather it’s a side effect of a medication, a sign of depression or someone is simply anxious and worried. Being able to reassure at least some patients that they are not at significant near-term risk of AD is something we never could do in the past, given the high prevalence of the disease.”