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 annual American College of Neuropharmacology meeting in San Juan, 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. In the latest study, 150 patients ranging in age from 43 to 85 with memory problems and 63 healthy volunteers were asked to identify odors on a scratch card —— one card for each smell. They were given a choice of answers. Most normal people score between 35 and 40. People in the earliest stages of Alzheimer’s, before cognitive difficulty renders them unable to understand the exercise, score in the 20s. Many of the participants arrived at Columbia’s Memory Disorders Center complaining of problems. In follow-ups over nine years many were diagnosed with Alzheimer’s. Those who scored in the low 20s were at high risk for Alzheimer’s. Inability to identify smoke best predicted Alzheimer’s. The others smells were menthol, leather, lilac, pineapple, soap, strawberry, natural gas, lemon and clove. —LAT-WP
