 |
 |
I apologize for the length of this post, but it is so interesting, it is worth reading... Copyright © 1998 Nando.net/Copyright © 1998 Scripps Howard MILWAUKEE (March 14, 1998) -- When scientists examined the brain of an 86-year-old nun soon after her death, they found it was riddled with signs of Alzheimer's disease. Twisted fibers of protein called tangles and collections of protein masses called plaques littered the top of her brain, called the neocortex. Indeed, few brains they had ever examined among Alzheimer's disease patients had so many of these protein abnormalities. In addition, genetic tests showed the woman had two copies of the APOE4 gene. Studies had previously shown that people with two copies of the gene have a roughly two-fold risk of developing Alzheimer's compared to someone without the gene. But the biggest shock came when the scientists matched the brain with the identity of the nun. What they found was that the nun, at the time of her death, had as quick and agile a mind as any nun of her age group -- 80s -- in the study. During a mental capacity test not long before her death, the nun from the School Sisters of Notre Dame not only quickly identified the season, month and exact date, but within several minutes correctly estimated the time of day, although she had no access to a watch or clock. "At first we didn't think we had the right brain," said David A. Snowdon, director of the Sanders-Brown Center on Aging in Lexington, Ky. But checking confirmed the identity. The nun had an "Alzheimer's brain" but not a single symptom of Alzheimer's disease. At about the same time, the scientists also were examining the brain from another nun of similar age. She, too, had tangles and plaques but not nearly as many as the other nun. She also had only one copy of the APOE4 gene, not two. But when this second nun had been given the memory test shortly before she died, she was unable to answer any of the questions correctly and she couldn't even remember she was being tested. The explanation? The second nun previously had suffered two strokes. "It was a double whammy," said Snowdon. Actually more than a double whammy. What the two cases showed to researchers is that Alzheimer's is a disease with many contributing factors. And when just two -- strokes and the brain abnormalities in the second case -- combine, the result can be synergistic. "It is not one plus one equals two," Snowdon said. "It is more like one plus one equals six or seven." The factors that may contribute to Alzheimer's, hastening its onset and determining how serious it will be, are the goals of the now-famous Nun Study, of which Snowdon is the primary investigator. The study is examining the lives of 678 nuns, based on autobiographies they wrote when they entered the order at age 19; observations and tests in later years; and examination of their brain tissue after death. All the nuns are from the School Sisters of Notre Dame, an order founded in Munich that sent its first sisters to the United States in 1847 and set up its first U.S. motherhouse in Milwaukee in 1850. It is a unique study. Because the nuns' lives are so similar and their activities so well recorded by the order through the years, they make ideal study subjects, Snowdon said. He discussed the study and some of its findings at Froedtert Memorial Lutheran Hospital in Wauwatosa, Wis., during a recent gathering of health professionals and others interested in Alzheimer's disease. Alzheimer's disease is the most common of the disorders that cause dementia. Hallmark symptoms are loss of intellectual functioning, including memory, thinking and reasoning. It is estimated there are as many as 4 million Americans with the disease. The Nun Study is not the only major Alzheimer's study with connections to the state. In November, researchers at the Marshfield Medical Research and Education Foundations began a groundbreaking study examining medical use by Alzheimer's patients. The study is aimed at determining to what degree Alzheimer patients use the medical care system, compared with similar-age community residents without the disorder. Elaine Eaker, a senior research scientist and epidemiologist at Marshfield, in central Wisconsin, said the study would examine the current concept -- which could be a myth -- that such patients are high users of medical care and, therefore, costly compared to those without the disease. "In reality, for all we know, they may not be getting all the health care they need," Eaker said at a recent meeting sponsored by the Dementia Care Network, a coalition of Alzheimer's organizations and caregivers. "Might there be a bias in the system?" The study will examine the medical use of every person diagnosed with Alzheimer's or related dementia from July 1, 1991 to June 30, 1997, and a cohort of 400 community members without the disease. The groups will be matched by age and gender, based on medical records kept by the Marshfield Clinic and area hospitals. As for the Nun Study, it already is yielding results. Snowdon and his colleagues have found a connection between a person's language abilities early in life and the risk of Alzheimer's. In a nutshell, the autobiographies of nuns who were "idea dense" -- those who squeezed in the most thoughts in the least amount of words -- were less at risk for developing Alzheimer's. That suggests that people who have high intellectual functioning, who keep their brains active, might be protected against Alzheimer's. Head injuries at some point in life also have been shown to increase the risk of dementia later on, as do depression and exposure to heavy metals. The point: Snowdon maintains that Alzheimer's is less a consequence of simple aging as it is of progression of a disease process. "Whether you are going to get it is a long chain of events that can include lifestyle, diet, smoking, adequate medical care. If you layer all that on top of an Alzheimer's brain, we think that can trigger the symptoms," he said. "Keeping it at bay is really the issue." Which means, in his view, that Alzheimer's can be prevented in many cases. It will be up to the Nun Study, work at Marshfield and similar studies to tease out exactly what can be done to reduce the risk. By NEIL D. ROSENBERG, Milwaukee Journal Sentinel Judith [log in to unmask] (Judith Richards)