The inability to identify 10 everyday smells - from smoke to soap - can be used to predict Alzheimer's disease, scientists have discovered. The smell test was as effective at diagnosis as a memory test and better than a brain scan.
"It's easy to do," said Dr. D.P. Devanand, a professor of clinical psychiatry and neurology at Columbia Presbyterian Medical Center. His findings were presented this week at the American College of Neuropharmacology meeting in Puerto Rico.
While scientists have known for more than a decade that the brain's smell center is hard-hit in Alzheimer's, using smell tests to diagnose the disease has never caught on. Devanand has been testing the predictive value of a 40-item smell test developed by Richard Doty of the University of Pennsylvania. Most normal people score 35 to 40. People in the earliest stages of Alzheimer's score in the 20s.