July 18, 2011

Falls, Retina Changes Could Point To Alzheimer’s

A link between falling and Alzheimer's and a simple eye test that could help detect the disease were among the hot topics presented Sunday at the annual Alzheimer's Association International Conference, which opened this weekend in Paris, France.

Both studies were a part of an emphasis on pre-emptive Alzheimer's detection.

"I don't think we can wait until people develop Alzheimer's disease or mild Alzheimer's," Dr. William Klunk, a member of the Alzheimer Disease Research Center at the University of Pittsburgh Medical Center (UPMC) said at the conference, according to Julie Steenhuysen of Reuters. "I think we need to act before that."

"Brain scans and spinal fluid tests are used by researchers to detect Alzheimer's-related changes, but they are expensive and impractical for widespread screening, and none of them have been approved for routine use," Steenhuysen added. "So teams are looking for other early changes that offer evidence the disease is developing before symptoms occur."

According to Mary Brophy Marcus of USA Today, one group of researchers discovered that older individuals whose brain scans showed signs of protein aggregates known as brain amyloids are twice as likely to suffer a fall as those without amyloids, which are also early indicators of Alzheimer's.

The 125 subjects who participated in the eight month study were otherwise healthy and were submitted to a positron emission tomography (PET) scan--which uses a tracer to illuminate areas of the brain where amyloids were present. The subjects contributed samples of cerebrospinal fluid and were also asked to record the number of times that they suffered a fall, the USA Today reporter said.

"To our knowledge, this is the first study to identify a risk of increased falls related to a diagnosis of pre-clinical Alzheimer's disease," Susan Stark, an assistant professor of occupational therapy and neurology at Washington University in St. Louis, told Marcus. She added that their findings suggest "that higher rates of falls can occur very early in the disease process."

Jeffrey Burns, the director of the Alzheimer and Memory Program at the University of Kansas School of Medicine, told Marcus that while the amyloid study was a small one, the results were "interesting" and "likely to be of clinical importance down the road," including the possibility of prescribing bone medication or ordering physical therapy to potential Alzheimer's candidates.

In related news, Australian scientists led by Shaun Frost of the Commonwealth Scientific and Industrial Research Organization (CSIRO), "are reporting encouraging early results from a simple eye test they hope will give a noninvasive way to detect signs of Alzheimer's disease," AP Medical Writer Marilynn Marchione reported on Sunday.

"Although it has been tried on just a small number of people and more research is needed, the experimental test has a solid basis: Alzheimer's is known to cause changes in the eyes, not just the brain," she added.

Steenhuysen reports that the study authors, backed by Australia's national science agency, have been working to see whether or not changes in a person's retina could be used as an early detector for Alzheimer's disease. In particular, the researchers are looking at the width of specific blood vessels that they claim change significantly when a person is that risk for the disease.

"It is much easier for us to image the retina than it is for us to do a brain scan," Frost told the meeting, according to Reuters. "These findings are indicating a relationship between changes in the retina and the plaque burden in the brain."

Steenhuysen said that Frost believes that the retina test could be used "along with other biomarker tests to detect Alzheimer's early...The study needs to be confirmed by larger studies, but it shows one of the ways in which researchers are trying to find ways of diagnosing Alzheimer's early."

"More than 5.4 million Americans and 35 million people worldwide have Alzheimer's, the most common form of dementia," Marchione said. "It has no cure and drugs only temporarily ease symptoms, so finding it early mostly helps patients and their families prepare and arrange care."


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