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Signs of Alzheimer’s disease may be present decades before diagnosis

This is the kind of research that could make a big difference in the search for causes and therapies for Alzheimer’s. It is clear that the sooner the disease is diagnosed the better the chances of slowing the progression–that is where we are today. In the not so distant future as therapies evolve to slow the progression of disease early diagnosis will become even more important.

Adult head size can be used to estimate the size of the fully-developed brain. Previous studies have found that clinical expression of Alzheimer’s disease is related to head size, with people having smaller heads more likely to show the characteristic symptoms of this illness. Larger brains provide reserve against Alzheimer’s, allowing people to function normally despite having considerable Alzheimer pathology in their brains.



Signs of Alzheimer’s disease may be present decades before diagnosis

Scientists from the University of South Florida and the University of Kentucky report that people who develop Alzheimer’s disease may show signs of the neurodegenerative illness many decades earlier in life — including compromised educational achievement. Their research is published online this month in the journal Alzheimer’s Disease and Associated Disorders.

Participants in the Nun Study were studied to identify those who became demented before death or had characteristic brain changes of Alzheimer’s disease at autopsy. Among nuns who became demented or had evidence of Alzheimer’s disease at autopsy, those with small head sizes had significantly lower educational achievement in earlier adult life. In those dying without a dementia diagnosis or autopsy evidence of Alzheimer’s disease, head size had no relationship with education.

Adult head size can be used to estimate the size of the fully-developed brain. Previous studies have found that clinical expression of Alzheimer’s disease is related to head size, with people having smaller heads more likely to show the characteristic symptoms of this illness. Larger brains provide reserve against Alzheimer’s, allowing people to function normally despite having considerable Alzheimer pathology in their brains.

“If brain damage related to Alzheimer’s disease begins earlier in adult life, then having less reserve due to a smaller brain could compromise intellectual ability in those destined to get Alzheimer’s and lead to them getting less education,” said lead author James Mortimer, PhD, professor of epidemiology at USF.

“Although it has been known for many years that individuals with lower education have a greater risk of getting Alzheimer’s, this is the first report showing that reduced educational attainment may actually be an early sign of the underlying disease.”

The study findings add to others showing that individuals who will eventually develop Alzheimer’s differ from those who don’t many decades before. In 1996, the Nun Study found that Alzheimer’s disease with onset in old age could be predicted accurately from characteristics of autobiographical essays written at an average age of 22. Other studies have shown that those who develop Alzheimer’s have specific deficits on tests of memory and thinking decades before the disease is diagnosed. The fact that subtle signs of Alzheimer’s appear many years before symptoms appear may be useful for predicting who is at risk of the illness and identifying individuals earlier in life who could benefit from preventive therapies.

The Nun Study, begun in 1992, is a study of 678 Catholic sisters, initially 75 to 102 years of age, who were evaluated annually for dementia and who agreed to brain donation at the time of their deaths. The study is sponsored by the National Institute on Aging.

– USF Health-

USF Health is dedicated to creating a model of health care based on understanding the full spectrum of health. It includes the University of South Florida’s colleges of medicine, nursing, and public health; the schools of biomedical sciences as well as physical therapy & rehabilitation sciences; and the USF Physicians Group. With $308 million in research funding last year, USF is one of the nation’s top 63 public research universities and one of Florida’s top three research universities.

 
 

Signs of Alzheimer’s disease may be present decades before diagnosis

This is the kind of research that could make a big difference in the search for causes and therapies for Alzheimer’s. It is clear that the sooner the disease is diagnosed the better the chances of slowing the progression–that is where we are today. In the not so distant future as therapies evolve to slow the progression of disease early diagnosis will become even more important.

Adult head size can be used to estimate the size of the fully-developed brain. Previous studies have found that clinical expression of Alzheimer’s disease is related to head size, with people having smaller heads more likely to show the characteristic symptoms of this illness. Larger brains provide reserve against Alzheimer’s, allowing people to function normally despite having considerable Alzheimer pathology in their brains.



Signs of Alzheimer’s disease may be present decades before diagnosis

Scientists from the University of South Florida and the University of Kentucky report that people who develop Alzheimer’s disease may show signs of the neurodegenerative illness many decades earlier in life — including compromised educational achievement. Their research is published online this month in the journal Alzheimer’s Disease and Associated Disorders.

Participants in the Nun Study were studied to identify those who became demented before death or had characteristic brain changes of Alzheimer’s disease at autopsy. Among nuns who became demented or had evidence of Alzheimer’s disease at autopsy, those with small head sizes had significantly lower educational achievement in earlier adult life. In those dying without a dementia diagnosis or autopsy evidence of Alzheimer’s disease, head size had no relationship with education.

Adult head size can be used to estimate the size of the fully-developed brain. Previous studies have found that clinical expression of Alzheimer’s disease is related to head size, with people having smaller heads more likely to show the characteristic symptoms of this illness. Larger brains provide reserve against Alzheimer’s, allowing people to function normally despite having considerable Alzheimer pathology in their brains.

“If brain damage related to Alzheimer’s disease begins earlier in adult life, then having less reserve due to a smaller brain could compromise intellectual ability in those destined to get Alzheimer’s and lead to them getting less education,” said lead author James Mortimer, PhD, professor of epidemiology at USF.

“Although it has been known for many years that individuals with lower education have a greater risk of getting Alzheimer’s, this is the first report showing that reduced educational attainment may actually be an early sign of the underlying disease.”

The study findings add to others showing that individuals who will eventually develop Alzheimer’s differ from those who don’t many decades before. In 1996, the Nun Study found that Alzheimer’s disease with onset in old age could be predicted accurately from characteristics of autobiographical essays written at an average age of 22. Other studies have shown that those who develop Alzheimer’s have specific deficits on tests of memory and thinking decades before the disease is diagnosed. The fact that subtle signs of Alzheimer’s appear many years before symptoms appear may be useful for predicting who is at risk of the illness and identifying individuals earlier in life who could benefit from preventive therapies.

The Nun Study, begun in 1992, is a study of 678 Catholic sisters, initially 75 to 102 years of age, who were evaluated annually for dementia and who agreed to brain donation at the time of their deaths. The study is sponsored by the National Institute on Aging.

– USF Health-

USF Health is dedicated to creating a model of health care based on understanding the full spectrum of health. It includes the University of South Florida’s colleges of medicine, nursing, and public health; the schools of biomedical sciences as well as physical therapy & rehabilitation sciences; and the USF Physicians Group. With $308 million in research funding last year, USF is one of the nation’s top 63 public research universities and one of Florida’s top three research universities.

 
 

A Bigger Brain May Help Protect You from Alzheimer’s

While nobody can control the size of their brains, experts advise that mentally stimulating activities like completing puzzles, traveling, learning a new language, playing a musical instrument, or doing crossword puzzles can help stimulate new connections between brain cells.



A Bigger Brain May Help Protect You from Alzheimer’s

A large hippocampus – a part of the brain devoted to memory – may help ward off Alzheimer’s disease, a new study reports. The findings offer new clues into why some elderly people remain mentally sharp and alert well into their 80s and beyond, even though their brains are riddled with the plaques and tangles of Alzheimer’s disease.

The findings help support the notion of cognitive reserve, the theory that a brain rich in interconnections and working nerve cells may help to ward off the symptoms of Alzheimer’s disease even when a certain amount of brain tissue is already damaged. With a larger hippocampus, the more brain cells. According to the theory, if some cells die off from the ravages of Alzheimer’s or related ailments, enough cells remain so that people can continue to think and function normally..

From autopsies, researchers have long known that some people die with sharp minds and perfect memories, even though their brains are riddled with the plaques and tangles of Alzheimer’s disease. The new research suggests that people who have a larger hippocampus, a seahorse-shaped part of the brain that is critical for memory, may as a result be protected against Alzheimer’s.

“This larger hippocampus may protect these people from the effects of Alzheimer’s disease-related brain changes,” said study author Deniz Erten-Lyons, M.D., with Oregon Health & Science University in Portland. “Hopefully this will lead us eventually to prevention strategies.”

For the study, presented April 15 at the American Academy of Neurology 60th Annual Meeting in Chicago, researchers evaluated the brains of 12 people who had sharp memories and thinking skills at the time of their death. Autopsies revealed that their brains contained large numbers of Alzheimer’s plaques, even though they remained mentally sharp and alert. Their brains were compared to those of 23 people who had the same amount of plaques in their brains, but had been diagnosed with Alzheimer’s disease before death.

Researchers found that the volume of the hippocampus area of the brain was 20 percent larger in the cognitively intact group compared to the Alzheimer’s disease group with dementia. There were no other demographic, clinical or pathological differences between the groups. The results remained the same regardless of whether they were men or women, their age and the total brain volume.

The findings help to explain why many people remain mentally sharp well into their 80s and beyond, even though autopsies after death show that their brains contain extensive damage like that seen in Alzheimer’s disease.

While nobody can control the size of their brains, experts advise that mentally stimulating activities like completing puzzles, traveling, learning a new language, playing a musical instrument, or doing crossword puzzles can help stimulate new connections between brain cells. These strengthened connections may help to preserve thinking and memory. Maintaining strong social ties and exercising into old age may also help to protect the brain, studies show.

To learn more about keeping the brain young, visit http://www.ALZinfo.org, The Alzheimer’s Information Site.

By alzinfo.org, The Alzheimer’s Information Site. Reviewed by William J. Netzer, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.
Source: Presented at the American Academy of Neurology 60th Anniversary Annual Meeting in Chicago, April 12 to 19, 2008.

 
 
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