||Panel chair Dr. Martha Daviglus delivers the conference state-of-the-science statement.
Plaques and Tangles
First described in 1906 by German psychiatrist-neuropathologist Alois Alzheimer, the disease named after that physician is the most common
form of dementia. Alzheimer wrote of a 51-year-old female patient who showed signs of memory loss, language problems and unpredictable
behavior. After she died, he studied photomicrographs of her brain and found what became the hallmarks of the disease: abnormal
clumps of protein identified as “beta-amyloid
plaques” and disorderly bundles of protein called “neurofibrillary tangles.”
Over the course of a lifetime, most people remain cognitively stable, experiencing only limited declines in short-term memory and processing
speed. But for some, the loss in memory and cognitive function is more severe and, ultimately,
interferes significantly with daily life. That’s when the possibility of Alzheimer’s or another form of dementia must be considered.
What the Panel Found
Panelists Dr. Wade Berrettini (l) and Dr. Carl Bell.
Panelists Dr. Kathleen McGarry (l) and Gail Hunt.
Dr. Mary Ganguli of Western Psychiatric Institute and Clinic, University of Pittsburgh Medical Center, gives an overview
of Alzheimer’s disease.
What complicates diagnosis, according to several
conference presenters, is that physicians at the primary care level may not have enough time or sensitive enough tools to determine the nature of a patient’s memory loss. For example, what differentiates normal, age-related cognitive
decline from mild cognitive impairment or from the earliest stages of Alzheimer’s disease?
What used to be a rarely reported disease, the panel noted in its introduction, Alzheimer’s now has become “one of the most common disabling disorders among older individuals.” Alzheimer’s accounts for 60 percent to 80 percent
of all dementia diagnoses, depending on the criteria used. Estimates vary, but experts report between 2.6 million and 5.1 million Americans may have the disorder. That number is expected to grow as Baby Boomers age.
The 15-member panel included experts in a number of relevant fields such as geriatrics, neurology,
preventive medicine, psychiatry, human nutrition, pharmacology and nursing. Specifically
selected not to be experts in Alzheimer’s disease
and cognitive decline, and therefore without
preconceptions of the conference questions, the panel drew several conclusions:
- 20 years of extensive research has provided
substantial information on the nature of Alzheimer’s disease and cognitive decline. While critical knowledge gaps still remain, particularly in the areas of causes and prevention, a number of observational studies and a few short-term clinical trials offer new insights.
- Currently, outside of a neurologist’s office or research setting, there are no “highly reliable consensus-based diagnostic criteria for cognitive
decline, mild cognitive impairment and Alzheimer’s,” and available criteria at the clinician
level are not “uniformly applied.”
- Alzheimer’s and related ailments are major sources of disability and death worldwide that significantly burden not only those who have the diseases, but also their caregivers and society
- The medical community does not have enough evidence to support using any drug, dietary supplement or behavioral change to prevent
Alzheimer’s or cognitive decline. Results from ongoing studies in some of these areas, including studies of antihypertensive medications
and physical activity, could possibly shed more light on warding off the disorders. However,
it is too soon to conclude that any intervention
is effective in preventing Alzheimer’s or cognitive decline, the panel noted repeatedly.
- Large-scale population-based studies and randomized controlled trials—the gold standard
evidence in medical research—will be needed to look into strategies that may help maintain cognitive function in people at risk for decline and find ways to delay onset and slow progression of Alzheimer’s disease.
Facts, Not Fiction
One of close to two dozen expert presenters at the recent conference on cognitive decline, Dr. Ronald Petersen of the Alzheimer’s Disease Research Center at Mayo Clinic College of Medicine, discusses early diagnosis of the disorder.
At a public reading of the panel’s draft statement on day 3, several audience members expressed dismay that the conclusions were overly negative
and pessimistic. During an afternoon media teleconference, several panel members addressed these concerns and sympathized with the public’s frustration, emphasizing the importance of basing
their findings on scientific evidence.
“Physicians can actually benefit from the information
contained in this report,” said panelist Dr. Evelyn Granieri of Columbia University. “It provides them with factual information.”
Another panelist, Dr. Carl Bell of the University of Illinois at Chicago, said, “From a personal perspective,
being 63, I’m scared to death of this disorder
and I know that a lot of my Baby Boomer colleagues are also terrified.”
Such fears, the panel acknowledged, can cause people to spend money on herbal treatments and other interventions that have not been proven. That’s exactly where panel members hope this report can help.
“Since we don’t have any solid evidence that there is anything to prevent either cognitive decline or dementia, we hope physicians will discuss this report with their patients and…dissuade folks who have this and their caregivers from spending extraordinary amounts of money on stuff that doesn’t work,” Bell concluded.
In the meantime, there is something people can do to help fight Alzheimer’s, another panelist pointed out.
“One of the most important things doctors and people who start to recognize problems can do is to get engaged in the research community,” said Dr. Arnold Potosky of Georgetown University. “There’s a vital need for more research. Our conclusions
were heavy on recommendations to do more to track these diseases over the long term, to learn more about their causes and progression.”