New guidelines define pre-Alzheimer's disease

The first new guidelines for diagnosing Alzheimer's disease in nearly 30 years don't suggest that doctors change how they evaluate and treat patients now, but do pave the way for improvements.

The guidelines establish earlier stages of the mind-robbing disease, reflecting a modern view that Alzheimer's is a spectrum of mental decline, with damage that can start many years before symptoms appear.

But despite the hoopla about new brain scans and blood and spinal fluid tests that claim to show early signs of Alzheimer's, the guidelines say they are not ready for prime time and should remain just tools for research.

About 5.4 million Americans and more than 26 million people worldwide have Alzheimer's, the most common form of dementia.

The guidelines are in Alzheimer's & Dementia: The Journal of the Alzheimer's Association.