Sometimes when a patient tells his opthalmologist that he "can't see," what he really means is "I can see, but I can no longer read or write." In a minority of Alzheimer's patients, the disease shows up first as problems with vision rather than memory or other cognitive functions. But diagnosis can be difficult because standard eye exams are often inconclusive for these patients.
In a surprising reversal of long-standing scientific belief, researchers at the Mayo Clinic campus in Florida have discovered that inflammation in the brain is not the trigger that leads to buildup of amyloid deposits and developmentof Alzheimer's disease.
In fact, inflammation helps clear the brain of those noxious amyloid plaques early in the disease development, as seen from studies in mice that are predisposed to the disorder, say the researchers in the online issue of the FASEB journal.
Elderly people exhibiting memory disturbances that do not affect their normal, daily life suffer from a condition called "mild cognitive impairment" (MCI). Some MCI patients go on to develop Alzheimer's disease within a few years, whereas other cases remain stable, exhibiting only benign senile forgetfulness. It is crucial to develop simple, blood-based tests enabling early identification of these patients that will progress in order to begin therapy as soon as possible, potentially delaying the onset of dementia.
The eyes may be the windows to the soul, but new research indicates they also may mirror a brain ravaged by Alzheimer's disease.
UC Irvine neuroscientists have found that retinas in mice genetically altered to have Alzheimer's undergo changes similar to those that occur in the brain -- most notably the accumulation of amyloid plaque lesions.
In addition, the scientists discovered that when Alzheimer's therapies are tested in such mice, retinal changes that result might predict how the treatments will work in humans better than changes in mouse brain tissue.
As many as 5.3 million persons in the United States are living with Alzheimer's disease, and an additional 10 million US baby boomers are proejcted to be at risk over their lifetime. Worldwide, with the rapid increase in the older population, Alzheimer disease and related dementias will affect an increasing number of families, with major societal and economic implications. Hence, these are conditions likely to be encountered by a wide range of clinicians.
When MIT biology professor Leonard Guarente started looking for the Fountain of Youth through this microscope more than a decade ago, compatriots were hard to come by.
"Even my own colleagues thought I was nuts," said Guarente, whose studies of the metabolic pathways in yeast cells might lead to drugs that reverse and prevent aging. "But the scientific community has done a complete 180 in the past 20 years."
Dementia is often viewed as a disease of the mind, an illness that erases treasured memories but leaves the body intact.
But dementia is also a physicial illness, too - a progressive, terminal disease that shuts down the body as it attackes the brain. Although the early stages can last for years, the life expectancy of a patient with advanced dementia is similar to that of a patient with advanced cancer.
One early summer Saturday, Ted Clapp, a retired minister and psychologist, invited about twenty of his children, grandchildren, and great-grandchildren to lunch at his place north of Portland, Maine. He had set out some family treasures - including arrowheads found on his grandfather's farm, watercolor paintings by some "ancient ancestor," an antique trumpet, and his great-grandfather's sword - that he'd collected over his ninety years.