Scientists Propose New Way to Define Alzheimer's

About 50 million people in the world have dementia -- and Alzheimer's is the most common form. The US government and other scientists are now proposing a new way to define Alzheimer's – which will affect how many people are diagnosed with the disease. Dr. Clifford Jack Jr. at the Mayo Clinic led a panel of experts who worked with the Alzheimer's Association and the National Institute on Aging to update guidelines on the disease. They want the new definition based on biological signs, such as brain changes as seen on scans -- rather than memory loss and other symptoms. They would measure certain forms of two proteins that form plaques and tangles in the brain as well as nerve injury, degeneration or brain shrinkage.