by Rita Rubin Asking questions can determine whether the risk is high or low
For the elderly, misplaced keys or a forgotten address represents more than inconvenience. Such lapses might portend a dread descent into the nothingness of Alzheimer's disease or another form of dementia. New findings, however, suggest it is possible to identify older people most and least likely to develop dementia. But predicting that a seemingly healthy person is doomed to suffer a terminal illness raises a host of ethical issues. Until they can be resolved and the techniques refined, dementia forecasting is best considered mainly a research tool.
"I've been very frightened that someone would perceive this as a sort of do-it-yourself kind of thing," says neuropsychologist David Masur, lead author of a study in the August issue of Neurology that reports on using standard psychological tests to predict dementia among the healthy elderly. "You'd walk into your neighborhood pharmacy, and there would be your home pregnancy test and Masur's Alzheimer's test."
Masur found that a combination of four tests can signal an especially low or high risk of dementia within four years. In one test, the elderly person names objects in a category as rapidly as possible. In a second test, the individual repeats 12 words recited by the examiner, then tries to recall them. A third test asks the person to remove objects from a bag, return them and remember what they were. And a fourth test asks the subject to match symbols with numbers.
Because dementia takes various forms, the tests were more accurate in predicting who would not get it than who would, says Masur, an associate clinical professor of neurology at the Albert Einstein College of Medicine and Montefiore Medical Center in the Bronx. He and his colleagues tested 317 healthy people ages 75 to 85, then followed them for four years. Of the 212 subjects who scored well, 202 did not develop dementia, a prediction rate of 95 percent. Of the 13 with very low scores, 11 got dementia -- a prediction rate of 85 percent. Of the 92 who scored in the middle, 43 developed dementia and 49 did not.
Future use. Masur has been fielding phone calls from older people interested in taking the tests. The majority will be reassured -- and Masur says even those whose results suggest they're at high risk for dementia can benefit. "Being alerted to the fact that this is a possibility might make the adjustment easier," he says, noting that identifying impending dementia will become increasingly important as treatments emerge that could stave it off.
The tests are widely available, and Masur's report includes guidelines for clinicians in using them to determine patients' dementia risk. He emphasizes that low scores should lead to evaluation by a physician to rule out depression, overmedication or other treatable causes.
Consulting a doctor, not taking a test, should be the first step by anyone who suspects incipient Alzheimer's, the leading cause of dementia, says Alzheimer's expert Leonard Berg of the Washington University School of Medicine in St. Louis. Although no one in Masur's study had obvious signs of dementia, examination by a physician probably would have revealed that some did have very mild Alzheimer's, says Berg. He praises Masur's work for its accuracy and simplicity, which make it valuable for research.
Screening symptomless individuals for dementia poses several dangers, says medical ethicist Stephen Post of Case Western Reserve University in Cleveland. For example, without proper counseling, people might be unequipped to handle bad news, says Post, who wrote about the issue in July in the Journal of the American Geriatrics Society. "I think many people fear dementia more than cancer, because they're concerned with the loss of self-identity." For some, though, uncertainty about the future might be even more unbearable.
