What if we could identify Alzheimer's patients even before they started forgetting words, getting lost in familiar places, and not recognizing friends and loved ones? Would we be able to prevent the disease from progressing or even occurring? That scenario is looking more and more likely, according to scientists, who are busy testing hundreds of new Alzheimer's drugs. The trick is to catch people before the brain has obviously deteriorated, when it is too late to do anything. But how do you catch impending Alzheimer's when patients are still acting and functioning normally?

Researchers have discovered that a simple spinal tap may be the key to identifying those who are heading toward Alzheimer's. A decade or more before any obvious behavioral changes start, scientists say, a telltale level of abnormal proteins usually appears in a person's spinal fluid. A recent study of more than 300 people in their 70s revealed that almost 100 percent of those with Alzheimer's had elevated protein levels. Three-quarters of those with mild cognitive impairment, which can precede Alzheimer's, had elevated protein levels. And a third of people with no obvious impairment had elevated levels as well, suggesting Alzheimer's some time in the future. A separate study of 57 older people with mild cognitive impairment who went on to develop Alzheimer's revealed that every single one of them had elevated protein markers in their spinal fluid before Alzheimer's reared its head.

Although spinal-fluid tests are available to people now, not all doctors are offering them and not all patients are clamoring to take them. One reason is that medical conditions other than Alzheimer's can affect memory. Another is that the spinal tests may not be completely reliable since results have been known to vary from lab to lab. A third reason is that spinal taps in general make people nervous.

And there's a larger question to ponder: Do we necessarily want to know that we're going to develop Alzheimer's? Possibly not at the moment, when there's still little that can be done to stop the disease. But scientists are optimistic that the day will come when drugs that slow or prevent the disease are approved. In that case, we would certainly want to know what lies in wait so we can change the course of our future health.



National Institutes of Health, http://clinicaltrials.gov

Arthritis Foundation, www.arthritistoday.org

National Cancer Institute, www.cancer.gov