(CBS News) - In Bethesda, Md. Monday, the National Institutes of Health began hosting a two-day summit on the fight against Alzheimer's disease. More than 5 million Americans have the disease, a number expected to triple by 2050. And researchers trying to defeat the disease are facing an unexpected hurdle, as CBS News correspondent Wyatt Andrews reports.
It's the largest clinical study ever done on Alzheimer's disease. With almost 500 patients submitting to MRI scans, PET scans and even spinal taps, researchers hope to invent the first ever test to find Alzheimer's before a patient loses any memory -- or even knows there's a problem.
"We may be able to screen and begin treatment even before any symptoms begin," said Dr. Raymond Turner of Georgetown University Medical Center, one of 57 centers participating in the study.
Researchers are using thousands of images to try to develop a test for the disease. Learning how a brain with Alzheimer's shrinks over time is one key to early detection. Another is spotting the buildup of toxic proteins in the brain, one of known hallmark signs of the disease.
The project has excited researchers around the world. But there's a problem and its findings have been delayed by at least a year.
"The problem is finding volunteers to join the studies," Turner said. "Patients."
This one study of 750 patients is 250 patients short. Nationally, the shortfall is in the thousands, with almost every clinical trial related to Alzheimer's needing more volunteers.
The disease itself is part of the problem. Patients who aren't aware they have the disease don't know to volunteer, and patients with mild memory loss are often afraid of becoming guinea pigs.
The lead researcher of the imaging trial, Dr. Michael Weiner, says one answer is recruiting the doctors who treat Alzheimer's patients
"We definitely could do a better job trying to get physicians to refer patients to our project," Weiner said. "The slower our trial goes, the slower the rate of progress."
For some of the patients in the imaging trial, Alzheimer's is personal. Seventy-nine-year-old Marian Myles is undergoing 18 months worth of memory tests and brain scans because Alzheimer's has stricken her husband.
"When I think it might touch my children and my grandchildren -- I do want a good diagnosis and a good cure for this," Myles said. Participating, she said, "Is not too hard at all."
The president's national plan to combat Alzheimer's, due this month, will recommend that research funding increase fourfold to $2 billion a year. But the roadblock now isn't the lack of funding for research -- it's the lack of patients to be in the research.
More information and how to help:
The lack of patients volunteering for clinical trials and studies related to Alzheimer's disease has grown acute, according to the NIH, advocacy groups and to leading researchers.More on Alzheimer's from the NIH
Most scientists -- no matter how excited they are at unraveling the secrets of the disease -- also fear that the lack of research volunteers may be delaying breakthroughs in early detection and drug therapies to reverse or cure the disease.
The stakes are growing by the day. On the top-10 list of killer diseases, only Alzheimer's continues to kill more people every year (death rates are down for all the others). And only Alzheimer's lacks a treatment capable of beating the illness. The long-term costs of Alzheimer's care make this one disease, by itself, a financial threat to Medicare.
The largest and most comprehensive study is called ADNI-2, the second version of the Alzheimer's Disease Neuroimaging Initiative, a national $140 million project that's roughly 250 patients short of its enrollment goal.
For more information, or to enroll or refer a patient, please visit the ADNI website here.
Another project seeking to match patients with trials and studies is sponsored by the Alzheimer's Association, and can be found through the association's website, here.