Alzheimer's Disease : Diagnosing

by National Institute on Aging

(Page 9 of 16)

Scientists are now exploring ways to help physicians diagnose AD earlier and more accurately. For example, some studies are focusing on changes in personality and mental functioning. These changes can be measured through memory and recall tests. Tests that measure a person's abilities in areas such as abstract thinking, planning, and language can also help pinpoint changes in function. Researchers are working hard to improve these standardized tests so that they can better track the changes that might point to early AD or predict which individuals are at higher risk of developing Alzheimer's Disease in the future.

Other studies are examining the relationship between early damage to brain tissue and outward clinical signs. Still others are looking for changes in blood chemistry that might indicate the progression of Alzheimer's disease.

One of the most exciting areas of ongoing research in this area is neuroimaging. Over the last decade, scientists have developed several highly sophisticated imaging systems that have been used in many areas of medicine, including Alzheimer's disease. Positron emission tomography (PET), single photon emission computed tomography (SPECT), and magnetic resonance imaging (MRI) are all examples. These "windows" on the living brain can help scientists measure the earliest changes in brain function or structure in order to identify those people who are at the very first stages of the disease - even before they develop signs and symptoms.

These types of scans are still primarily research tools, but one day, neuroimaging might be used more commonly to help physicians diagnose AD early. These tools may even be used someday to monitor the progress of the disease and assess patient responses to drug treatment.

The Human Side of AD Research

The Religious Orders Study and the Nun Study: Lives of Service Continue Even After Death

One way that scientists have tried to unravel the mystery of Alzheimer's Disease and other complex diseases, like heart disease or cancer, is to compare the characteristics, lifestyles, and disease rates of different groups of people. This approach has often provided clues as to why some people get a disease and others don't.

Another way is to study one group of people over time. The notion here is that data gathered over a period of years will reveal important clues about the origins of the disease under investigation. The knowledge gained also may lay the foundation for future treatment or prevention strategies. The Framingham Heart Study is one famous example of this kind of study. It has followed two generations of Massachusetts residents for 50 years, and its findings have revolutionized the way we think about, treat, and prevent heart disease.

The National Institute on Aging is funding two Alzheimer's disease studies that are using this approach - but with a unique twist. These studies involve members of religious communities.

Since 1990, scientists have been working with more than 650 nuns of the School Sisters of Notre Dame, who are located in various parts of the U.S. The Nun Study is an expansion of a pilot project begun in 1986 with a School Sisters of Notre Dame convent in Mankato, Minnesota.

Since 1993, scientists have also been investigating the mental and physical capacities of older nuns, priests, and brothers in the Religious Orders Study. More than 30 religious communities in a dozen States are participating in this study.

All of the participants in both studies agree to have detailed physical and mental function exams every year. Volunteers may spend decades in the study, repeating the tests each year. These exams help researchers better understand the effects on the brain of aging, AD, and other disorders. Participants also agree to donate their brains to the study when they die. This allows the investigators to match many years' worth of clinical and psychological information with the results of examinations of after-death brain tissue. These volunteers consider participating in these studies a wonderful chance to continue their lives of service to others. As one participant in the Nun Study put it, "[They] can have my brain. What good is it going to do me when I'm six feet under?"

The large numbers enrolled in the study ensure that some volunteers will still have normal brain function at the time of death. Others will have developed the clinical signs of AD. Still others will have other neurological disorders, such as Parkinson's disease. The yearly examinations enable researchers to detect signs of Alzheimer's Disease among participants and to track, year by year, the progress and treatment of the disease among those who develop it.

But why work with religious orders? What's special about them? One reason why members of religious orders are good study participants is that they often live together and have similar lifestyles, educational levels, daily routines, and activities. This cuts down on the variations among participants that make it difficult for scientists to interpret research results. It also makes it easy for study staff to keep track of volunteers over time and to maintain complete information on them.

About the Author

www.nia.nih.gov
NIA, one of the 27 Institutes and Centers of NIH, leads a broad scientific effort to understand the nature of aging and to extend the healthy, active years of life. In 1974, Congress granted authority to form NIA to provide leadership in aging research, training, health information dissemination, and other programs relevant to aging and older people.