WEDNESDAY, June 8, 2011 (HealthDay News) -- Brain scans that detect early warning signs of Alzheimer's may be available in the United States as soon as this year, researchers reported this week, though it may be too early for the scans to be of much help for those with the disease.
"You'll get a more accurate and earlier diagnosis, which can be important to people who want to know what's going on when their memory is starting to decline," said Dr. Christopher Rowe, lead author of one study on the scans. "Unfortunately, until there's an effective therapy, there's nothing that can be done to stop the progression of the disease. The real value is going to come when we have an effective therapy."
According to the Alzheimer's Association, the disease is the sixth leading cause of death in the United States, and the number of deaths has risen in recent years.
Rowe and other researchers just released studies that reveal the effectiveness of PET scans that search for signs of a protein in the brain called beta-amyloid. It essentially gunks up the brain and causes senility.
In one of three new studies, researchers from University of Texas found that levels of the protein, as detected through a PET scanner, were higher in those whose brains took longer to process things. In older people, they linked higher levels to memory problems.
Physicians who find signs of senility in people who undergo brain scans have limited options to help them. There's no cure for the illness, and drug treatments have not proven to be very effective.
Rowe, who's director of nuclear medicine at the Center for PET at Austin Hospital in Melbourne, Australia, said that one company, Avid Radiopharmaceuticals, hopes to get federal approval for amyloid scanning technology by the end of the year. Rowe has consulted for the company.
The scans won't be cheap, according to Rowe, potentially costing thousands of dollars each in the United States. But they accurately diagnose Alzheimer's about 90 percent of the time, he said, compared with an 80 percent rate that physicians reach on their own. And, he said, the scans can detect Alzheimer's at an early stage.
Dr. James R. Burke, director of the Memory Disorders Clinic at Duke University Medical Center, wondered about the value of diagnosis via scanner.
"Would you scan all people over a certain age?" he asked. "What do you say to a cognitively normal individual with increased amyloid in his/her brain that you would not advise for the same person without amyloid? If we had a therapy that reduced amyloid and prevented cognitive decline, then an argument could be made for widespread use of these scans."
However, Burke said, the study of brain scans does have value now as a research tool.
The studies were scheduled to be presented at the annual meeting of the Society of Nuclear Medicine, June 4 to 8 in San Antonio, Texas. Experts note that research presented at meetings should be considered preliminary because it has not been subjected to the rigorous scrutiny given to research published in medical journals.
More information
The U.S. National Institute on Aging has more on Alzheimer's disease.
