Mayo Clinic researchers publish standards for normal memory in older African-Americans

Monday, May 23, 2005

JACKSONVILLE, Fla., May 23, 2005 — A group of doctors at Mayo Clinic in Jacksonville have developed a set of normative standards for neuropsychological testing of cognitive function in older African-Americans. Their standards should lead to more accurate diagnosing of Alzheimer's disease and other forms of dementia in this population.

"Up until now, we've been comparing older African-American patients to normative groups comprised mostly of Caucasians," says Mayo Clinic neuropsychologist John Lucas, Ph.D. "They did not share the same background, particularly the same educational experiences. As a result, currently existing norms for a number of commonly used tests often overcall the frequency and severity of cognitive impairment in African-Americans."

Lucas and his colleagues in Mayo's Alzheimer's Disease Research Center (funded by the National Institute on Aging) designed a study to determine what constitutes normal memory and cognition for older African-Americans raised and educated in the South during segregation. "At that time, there were a host of differences in the educational systems between the Caucasian and African-American communities," he says. "We know that education has a strong effect on a person's test scores, and therefore any systematic differences in education must be accounted for when designing test procedures and evaluating test results. Most dementia tests can account for differences in the number of years of education someone completed. But they don't address other potential differences in education that existed between Caucasians and African-Americans before desegregation."

Dr. Floyd Willis is a Mayo Clinic family practice physician with an interest in racial disparities in health care. He says using normative standards developed for a dissimilar group of people can lead to telling some people they have dementia when they do not. This, in some cases, can preclude them from early interventional treatments and in other cases does not allow early detection of memory loss. "At some point in the future there may be medications, vaccines or therapies that will prevent or effectively treat these kinds of memory problems," Willis says. "It will be critically important to be able to identify early memory loss in all people using procedures and tools that are cross-culturally sensitive. Otherwise, we could find ourselves in the conundrum of having treatments that are available for early memory loss, but have subsets of people in whom we cannot diagnose very early memory loss."

Lucas, Willis and their collaborators will publish their normative standards, which resulted from their eight-year research project, in the May 2005 issue of The Clinical Neuropsychologist. Their final sample included data from 309 African-American volunteers from the Jacksonville area between the ages of 56 and 94.

As important as their work will be in accurately diagnosing dementia, Lucas acknowledges the new normative standards won't necessarily be universally applied to all African-Americans. "It's really going to be up to the clinician to decide," he says. "A doctor who evaluates an elderly African-American patient who was raised and educated in the segregated South will likely find these norms to be very helpful, whereas he or she may decide to use other normative comparisons if the patient was educated elsewhere. The importance of these norms lies in their ability to characterize normal memory functioning in a large segment of the African-American community who shared similar, disadvantaged educational opportunities. The appropriate use of these norms will not only help us identify memory problems when they are present, but they will help avoid misdiagnosing memory impairment in normal patients."

To explore this line of research further, Lucas and investigators from five universities around the country are putting together a consortium grant for a study of cognitive function in older African-Americans. The sample will include people from different regions of the country and both rural and urban locations.

Willis is currently conducting a pilot study on early memory loss that he hopes to expand. "This project — and my great interest — is to characterize a group of African-Americans with early memory loss and look at their vascular risk," he says. "In African-Americans, as opposed to Caucasians, it is very possible that early memory loss will be associated more with vascular risk factors and small strokes as opposed to Alzheimer's disease. We are in search of this information."

For his study, Willis is recruiting African-Americans older than 70 who have a memory complaint or believe their memory is not as good as friends and acquaintances their same age. Those interested in participating may call (904) 953-2677 for more information.

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Mayo Clinic is a multispecialty medical clinic in Jacksonville, Fla. The staff includes 313 physicians working in more than 40 specialties to provide diagnosis, treatment and surgery. Patients who need hospitalization are admitted to nearby St. Luke's Hospital, a 289-bed Mayo facility. Mayo Clinics also are located in Rochester, Minn., and Arizona. Visit www.MayoClinic.org/news for all the news from Mayo Clinic.

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