Alzheimer’s Disease :: Alzheimer’s Disease Neuroimaging Study

The Alzheimer’s Disease Neuroimaging Initiative (ADNI) – a project developed by the National Institutes of Health (NIH) – is seeking 800 older adults to participate in a study aimed at identifying biological markers of memory decline and Alzheimer’s disease (AD). Ultimately, scientists hope that brain and biological changes can be detected before memory decline and other symptoms appear, allowing the effectiveness of drugs to be evaluated at the earliest possible time.

The $60 million, 5-year ADNI study is the most comprehensive effort to date to identify brain and other biological changes associated with memory decline. The project was begun by the National Institute on Aging (NIA) and is supported by more than a dozen other federal agencies and private-sector companies and organizations. Investigators at 58 local study sites across the U.S. and Canada will be asking people ages 55 to 90 to become a part of this landmark research.

An estimated 4.5 million Americans have Alzheimer’s disease and that number is expected to grow as the population ages. ‘Finding therapies for and ways of preventing Alzheimer’s disease is critically important,’ says NIH Director Elias A. Zerhouni, M.D. ‘This extraordinary partnership is a major effort by the National Institutes of Health and the private sector to employ advanced technologies to detect memory decline and develop new drugs that can make a difference.’

“We encourage people to participate in this important study because it will help us to identify needed biological markers of memory decline and Alzheimer’s disease. These biomarkers could become comparable to the cholesterol measures now used as biomarkers for heart disease,” says Susan Molchan, M.D., program director for the ADNI project at the NIA. “In addition, using what we learn from the brain scans and other tests, we hope to lessen the time and cost of testing drugs and to bring treatments to patients much sooner.”

Scientists are looking for new ways to measure changes in the brain that occur with normal aging and with the progression of mild cognitive impairment (MCI), a subtle but measurable transitional state between the cognitive changes of normal aging and very early AD. People with MCI have memory impairments but otherwise function well and do not meet clinical criteria for dementia.

The ADNI researchers will employ serial magnetic resonance imaging (MRI); positron emission tomography (PET) scans; measurement of various biological compounds in blood, cerebrospinal fluid, and urine; and clinical and neuropsychological assessments to track MCI and early AD progression. MRI and PET scans are used in both medical practice and research to produce images of the brain. The study’s principal investigator (PI) is neuroimaging expert Michael W. Weiner, M.D., of the San Francisco Veterans Affairs Medical Center and the University of California, San Francisco. The Northern California Institute for Research and Education, a foundation affiliated with the U.S. Department of Veterans Affairs, has been awarded the multi-center ADNI grant.

Weiner explains that the 800 adults ages 55 to 90 sought for the study will be divided into three groups – approximately 200 cognitively normal older people will be followed for 3 years, 400 people with MCI will be followed for 3 years, and 200 people with early AD will be followed for 2 years. At the end of the study, the researchers will compare neuroimaging, biological, and clinical information from the participants, looking for correlations among the data to develop standards for tracking the progression of memory decline. A unique feature of the project is the development of an imaging and biomarker database that can be tapped by researchers in both the public and private sectors as they develop and test drugs for memory decline.

“Our goal is to ‘see’ critical brain changes and to identify biochemical indicators that may be useful in evaluating treatments aimed at slowing memory decline and AD,” explains Weiner.

Siemens, Philips, and General Electric, the three primary companies that develop and manufacture imaging equipment, are providing software support for the imaging aspects of the project.


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