Experts used to consider Alzheimer's a disease with only one stage - dementia. Now the Alzheimer's Association wants to recognize it as a three-stage disorder -- including early brain changes, mild cognitive impairment and full-blown Alzheimer's.
The first stage is preclinical, where the patient may not have any visible symptoms, but might experience abnormal changes in the brain -- such as a buildup of sticky plaque or protein tangles inside nerves -- that are detectable by brain scans and other imaging. Unfortunately, most of those scans are still in research settings, not the doctor's office.
The second stage is mild cognitive impairment, which includes mild memory issues and thinking changes that are enough to be noticed, but aren't debilitating.
Doctors say the last criteria for diagnosis is dementia, where memory, thinking and behavioral changes impair a person's ability to function on their own. This stage is toughest on patients and caregivers.
The change centers around the modern view that Alzheimer's disease is a spectrum of mental decline, with damage that can start many years before symptoms appear.
Doctors say the new guidelines give them the potential to detect changes in the brain at a much earlier stage. And Alzheimer's experts say it may breathe new life into finding a treatment or cure.
"That's going to allow us to find people earlier in the disease and develop drugs that actually will treat people earlier in the disease and prevent the dementia from happening," said Bill Thies, Chief Medical and Scientific Officer for the Alzheimer's Association.
Yet the guidelines do not advise doctors to change how they evaluate and treat patients now. Despite the hoopla about new brain scans and blood and spinal fluid tests that claim to show early signs of Alzheimer's, they are not ready for prime time and should remain just tools for research, the guidelines say.
Experts hope with the new diagnosing guidelines that insurers will consider expanding coverage for additional tests and medical care.
The National Institute on Aging and the Alzheimer's Association convened several expert panels to write the guidelines, the first since 1984 -- which were published Tuesday in Alzheimer's & Dementia: The Journal of the Alzheimer's Association.
The Associated Press contributed to this report.