BLOOD TEST TO PREDICT ALZHEIMER'S DISEASE

One of the most distressing aspects of Alzheimer's disease is the difficulty in determining whether mild memory problems are the beginning of an inevitable mental decline. Researchers at the Stanford University School of Medicine have developed a blood test that is a step toward giving people an answer two to six years in advance of the onset of the disease.

The test identifies changes in a handful of proteins in blood plasma that cells use to convey messages to one another. The research team discovered a connection between shifts in the cells' dialog and the changes in the brain accompanying Alzheimer's. They found that the blood test could indicate who had Alzheimer's with 90 percent agreement with clinical diagnoses, and could predict the onset of Alzheimer's two to six years before symptoms appeared.


Currently, the clinical diagnosis for Alzheimer's is one of exclusion -- by testing for other causes of memory loss and cognitive declines, such as stroke, tumors and alcoholism. If those conditions are eliminated as causes of memory loss, what remains is Alzheimer's, which is the most common cause of dementia. Even the clinical diagnosis is imperfect, and the only definitive diagnosis is by brain autopsy after a person has died.