June 13, 2003
Recently published guidelines from the U.S. Preventive Services Task Force, a panel of experts that reviews the scientific evidence and advises the government on preventive health issues, concluded that there is not yet enough evidence to recommend that doctors routinely test all their patients for early signs of Alzheimer's disease and other forms of dementia . However, if you, family members, or caretakers are concerned about any memory problems, including memory loss or confusion, you should let your doctor know, because testing may be helpful, the panel advised. The recommendations were based on research published in the June 3, 2003 issue of the Annals of Internal Medicine, a respected medical journal.
Diagnosing Alzheimer's can be difficult, because there are no surefire tests to detect the illness, particularly in the earliest stages, when problems with remembering and thinking may be very mild. The most common type of memory testing done in a doctor's office is the Mini-Mental State Examination, or MMSE. The MMSE consists of a brief questionnaire--several dozen questions--to assess the person's ability to recall specific facts and dates and awareness.
In some cases, testing may suggest that a person has Alzheimer's, when in reality they do not ("false-positive" results). In other cases, the tester may "miss" the diagnosis in a person who actually does have early Alzheimer's because he or she answered enough questions appropriately ("false-negative" results). If a person has difficulty on the MMSE or another "quick test," doctors will perform more rigorous memory tests.
The task force found that quick tests such as the MMSE are helpful for screening for dementia. However, only about half of people who test "positive" on these brief tests are found to actually have dementia on more rigorous testing. Accuracy depended in part on a person's age and educational level. "False-positive" results were more common in older people with lower formal educational levels. "False-negative" results, on the other hand, were more common in younger individuals with more schooling.
Alzheimer's Drugs, Other Findings
Early recognition of Alzheimer's is important, because it can help patients and their doctors better manage the course of therapy. Patients can, for example, participate in taking Alzheimer's drugs that may slightly slow the progression of the disease. Early diagnosis also helps family members and other caregivers anticipate and plan for future challenges in caring for the person with Alzheimer's.
The task force review of the latest evidence also reported some additional findings.
- Alzheimer's drugs such as Aricept, Exelon and Reminyl that are prescribed to treat memory problems in people with mild to moderate cognitive decline have only modest benefits, at best. On average, they slowed progression of the disease for up to seven months. In many cases, doctors may notice slight improvements in memory tests for up to a year. However, caretakers and family members may notice little or no improvement in the person's ability to go about daily activities and take care of themselves after about six months of treatment. These drugs have not proven effective in people with more advanced disease.
- There was only weak evidence that nutritional supplements may provide benefit for those with Alzheimer's. A few studies found that the Chinese herb ginkgo biloba may provide very slight benefits. A 2-year study of vitamin E found that it had no effect on thinking and memory and only limited evidence that it may delay the need to place a patient in institutional care. A review of another drug, called selegeline, did not provide any apparent benefits. Further testing of these and other products is needed.
- Non-drug therapies, such as behavioral training, caregiver education and support services for both patients and caregivers, may provide benefits. Benefits were most pronounced when health-care workers provided multiple services. Two studies found that caregivers were able to keep loved ones at home for 11 to 19 months longer when they received intensive and comprehensive help.
- In a small number of cases, memory problems may be due to treatable causes, such as a vitamin B12 deficiency, thyroid disease, infection, or sleep apnea (a breathing disorder that occurs during sleep). In those cases, screening for dementia is clearly helpful.
By Toby Bilanow, Medical Writer, for www.ALZinfo.org, The Alzheimer's Information Site. Reviewed by Samuel E. Gandy, M.D., Ph.D., Chairman of the Scientific Advisory Board, Fisher Center for Alzheimer's Research Foundation.