Announcements

  • October 15, 2009

    People with Alzheimer’s disease who had an episode of delirium experienced much faster cognitive decline than people with the disease who did not have delirium, a recent study shows. Delirium is a mental disorder characterized by restlessness, excitement, delusions, and/or hallucinations.

    Scientists from Harvard Medical School and Massachusetts General Hospital used data from the Massachusetts Alzheimer’s Disease Research Center’s patient registry to examine changes in cognitive performance over 15 years, in 408 older adults with Alzheimer’s, including 72 who developed delirium.

    Among patients with delirium, the annual decline in cognitive skills accelerated to twice the rate before delirium. Across the entire study group, the rate of decline was three times faster in those who had delirium compared with those who did not. The researchers conclude that information from this study will provide a foundation for future studies to determine whether prevention of delirium might delay cognitive decline in patients with Alzheimer’s disease.

    Fong, T.G., et al. Delirium accelerates cognitive decline in Alzheimer’s disease. Neurology. 2009. 72:1571-75.

  • June 15, 2010

    Dr. William Markesbery

    William R. Markesbery, M.D., who for more than 30 years was director of the University of Kentucky (UK) Sanders-Brown Center on Aging, died January 30, 2010, at age 77, in Lexington, KY. Dr. Markesbery led the UK Sanders-Brown Center on Aging from its founding in 1979 and was director of its Alzheimer's Disease Center. He also held the Commonwealth Chair in Aging and was professor of neurology, pathology, neurosurgery, and anatomy and neurobiology at the UK College of Medicine.

    Dr. Markesbery's studies of Alzheimer's disease received continuous NIH support for almost 30 years. He is credited with more than 410 peer-reviewed scientific publications and received numerous awards recognizing his work to find a cure for and prevention of Alzheimer's disease. The Journal of Alzheimer's Disease rated him among the top researchers in the world for the productivity and impact of his scientific study of Alzheimer's disease.

    From 1969 to 1972, Dr. Markesbery served as a faculty member at the University of Rochester School of Medicine and Dentistry and Strong Memorial Hospital in Rochester, NY. In 1972, he returned to UK and began his longtime career as a clinician and researcher. In addition to his College of Medicine appointments, Markesbery was a consultant in neurology and neuropathology at the Veterans Affairs Medical Center in Lexington.

    In 1974, he was the first to describe a rare form of heredity muscular dystrophy, now called Finnish-Markesbery Disease. In 1981, Markesbery and colleagues published one of several studies disproving the once-popular theory that an accumulation of toxic metals, such as aluminum, plays a role in the development of Alzheimer's disease. In 1991, they published the first study to demonstrate that oxidative stress is an important part of the pathogenesis of late-onset Alzheimer's disease and is present early in the disease.

    Dr. Markesbery received the Alzheimer's Association Khachaturian Award in 2009 for Outstanding Achievements in Advancing Alzheimer's Science.

    "Throughout his education and career, Bill Markesbery demonstrated his love for the University of Kentucky and his passion for Alzheimer's disease research," said Dr. Marcelle Morrison-Bogorad, director of NIA's Division of Neuroscience. "Without the work of leaders like him, our understanding of aging and Alzheimer's disease would not be where it is. We deeply appreciate Bill's contributions. He was a truly remarkable, dedicated professional whose work improved the quality of life for older Americans of this and future generations."

  • June 15, 2010

    More rigorous and long-term studies are needed before specific life style measures to prevent Alzheimer's disease and cognitive decline can be recommended, according to an independent panel convened by the National Institutes of Health (NIH). After reviewing medical literature and hearing speakers during an April 26-28 NIH State-of-the-Science Conference on Preventing Alzheimer's Disease and Cognitive Decline, the 15-member panel of clinical and scientific experts concluded that the existing evidence for drug, dietary, exercise, and other interventions is not yet sufficient to serve as the basis for clinical recommendations.

    Other conclusions by the panel included the following: There remain important and formidable challenges in conducting research on Alzheimer's disease and cognitive decline, particularly in the area of prevention. There are numerous ongoing or planned investigations which may offer promising new insights regarding the causes and prevention of these diseases. Cognitive decline and Alzheimer's disease pose a significant burden not only on affected individuals, but also on their caregivers and society. Firm conclusions cannot be drawn about the association of modifiable risk factors with cognitive decline or Alzheimer's disease. There is an absence of highly reliable consensus-based diagnostic criteria for cognitive decline, mild cognitive impairment, and Alzheimer's disease, and the available criteria have not been uniformly applied. There is insufficient evidence to support the use of pharmaceutical agents or dietary supplements to prevent or delay cognitive decline or Alzheimer's disease. Ongoing studies may provide new insight. Large-scale, population-based studies and randomized controlled clinical trials are critically needed to investigate strategies to maintain cognitive function and to identify factors that may delay onset of Alzheimer's disease in those at risk and that may slow the progression of Alzheimer's among individuals already diagnosed with the disease.

    The panel's final consensus statement can be found at http://consensus.nih.gov/2010/alzstatement.htm. NIA's ongoing Alzheimer's research program is actively investigating a variety of strategies to prevent or delay Alzheimer's and cognitive decline, including lifestyle strategies. You can find out more about the evidence thus far and what is being tested, including approaches like exercise and high blood pressure control, in the NIA booklet Can Alzheimer's Disease Be Prevented?

  • June 15, 2010

    People with early-onset Alzheimer's disease and "mixed dementias" are now eligible to receive social security benefits more quickly, thanks to an expansion of the Social Security Administration's (SSA's) Compassionate Allowance Program. According to the SSA, the purpose of the program is to waive the standard waiting period for benefits in order to "provide benefits quickly to applicants whose medical conditions are so serious that their conditions obviously meet disability standards."

    In a meeting on July 29, 2009, Alzheimer's experts and representatives from Alzheimer's Disease Centers (ADCs), as well as people struggling with these diseases, testified before SSA officials about the nature and effects of early-onset Alzheimer's and other dementias.

    NIA Deputy Director Dr. Marie Bernard explained the functions of the NIA, Alzheimer's Research Centers, and NIA's major Alzheimer's research initiatives, as well as the information and resources provided by the ADEAR Center. Among those testifying, Dr. David Bennett, Director of the ADC at the Rush University Medical Center, Chicago, provided an overview of the diseases. Sandra Weintraub, of the Northwestern ADC, explained how cognitive decline in early-onset disease is measured and differentiated from normal aging. Dr. Daniel Marson, Director of the University of Alabama at Birmingham ADC, testified on the impact of Alzheimer's disease on the capacity to work. Susan Frick, of the Rush ADC, testified regarding the emotional effects of Alzheimer's on people's ability to work. Darby Morhardt, also from Rush, discussed how families struggling with neurodegenerative diseases such as early-onset Alzheimer's have a host of psychological, social, family, and financial issues that are different from those of most people over 65.

  • June 15, 2010

    Allopregnanolone, a metabolite of the hormone progesterone that is made in the central nervous system, reversed neurological decline and improved performance on memory tests in 3-month-old mice with characteristics of Alzheimer's disease, a recent study showed. Allopregnanolone can increase the number of neural progenitor cells of mice and humans in vitro. In this study, led by researchers at the University of California, Los Angeles, the same molecule was given in vivo to triple transgenic Alzheimer's disease mice and to normal mice to test its effect on learning and memory. Allopregnanolone was found to regenerate nerve cells significantly in a part of the hippocampus—a region of the brain important to memory—in the transgenic mice but not in the normal mice. The Alzheimer's mice not only improved their performance on a trace eye-blink conditioning test of learning and memory, but performed as well as did the normal mice.

    Allopregnanolone can reverse cognitive deficits in an Alzheimer's mouse model, perhaps by helping certain nerve cells proliferate and thrive, the authors concluded. The findings, they say, suggest further investigation of allopregnanolone for its therapeutic potential in Alzheimer's disease.

    Wang, J.M., et al. Allopregnanolone reverses neurogenic and cognitive deficits in mouse model of Alzheimer's disease. Proceedings of the National Academy of Sciences USA. 2010. 107(14):6498-503. (PDF, 690K)

  • June 15, 2010

    Older adults with strong muscles are at lower risk of developing Alzheimer's disease and mild cognitive impairment than their weaker peers, researchers report in Archives of Neurology. The study builds on previous research showing a link between grip strength and Alzheimer's risk.

    In this study, researchers at the Rush University Alzheimer's Disease Center in Chicago measured a wide range of cognitive skills and muscle strength throughout the body in 970 participants with an average age of 80 years. During nearly 4 years of follow-up, 138 people developed Alzheimer's disease. After adjusting for age and other variables, the researchers found that the strongest 10 percent of participants had a 61 percent lower risk of developing Alzheimer's, compared with the weakest 10 percent of study participants. Muscle strength and mild cognitive impairment, a condition that often precedes Alzheimer's, were similarly but less closely linked. Stronger muscles were also associated with a slower rate of cognitive decline.

    The authors surmise that a common underlying disease process could account for the association between muscle weakness and declining cognition. Replication of the results in a population-based study is important, they add.

    Boyle, P.A., et al. Association of muscle strength with the risk of Alzheimer's disease and the rate of cognitive decline in community-dwelling older persons. Archives of Neurology. 2009. 66(11):1339-44.

  • June 15, 2010

    Cognitive fluctuations are common in people who have dementia with Lewy bodies, but they have rarely been assessed in people with Alzheimer's disease. According to one new study, such fluctuations do occur with Alzheimer's disease and are correlated with impaired performance on neuropsychological tests.

    The study found that older people with “cognitive fluctuations”—spontaneous changes in cognition, attention, and arousal—are more likely than people without these fluctuations to have Alzheimer's disease, according to researchers at the Alzheimer's Disease Research Center at Washington University, St. Louis. Of 511 subjects (average age, 78 years) in this NIA-funded study, 12 percent had cognitive fluctuations, defined as having three or four of the following symptoms: often feeling drowsy or lethargic during the day despite a good night's sleep, sleeping 2 or more hours before 7 p.m., having disorganized or unclear thoughts at times, and staring into space for long periods. Subjects with these symptoms were 4.6 times more likely to have Alzheimer's than were those without them, with disorganized, illogical thinking having the strongest correlation with dementia.

    These fluctuations may be possible new symptoms to be considered in the diagnosis of Alzheimer's disease, the study authors conclude.

    Escandon, A., et al. Effect of cognitive fluctuation on neuropsychological performance in aging and dementia. Neurology. 2010. 74:210-17.

  • June 15, 2010

    The cognitive health of older adults with “subjective cognitive impairment” (SCI) declined faster and further than that of people without SCI over a period of years, a recent study found. The study suggests that very early, subtle changes in memory in people who test as cognitively normal might predict more serious types of impairment.

    In SCI, people complain of memory problems but score in the normal range on tests of cognition. Complaints of cognitive impairment are commonly heard from older adults. In this NIA-supported study, 213 cognitively healthy subjects at least 40 years old—166 with SCI and 47 without—were followed for an average of 7 years after taking a series of baseline neuropsychological tests. Over that time, 54 percent of people with SCI progressed to mild cognitive impairment or probable dementia, compared with only 15 percent of people without SCI. The people with SCI declined faster, too, with an average time to decline of 5.3 years vs. 8.8 years for those without SCI.

    The study investigators, Dr. Barry Reisberg of the New York University School of Medicine and colleagues, suggest further studies be done of SCI in broader at-risk populations to assess the possibility of using SCI to identify individuals for prevention studies.

    Reference:

    Reisberg, B., et al. Outcome over seven years of healthy adults with and without subjective cognitive impairment. Alzheimer's & Dementia. 2010. 6(1):11-24.

  • June 15, 2010

    African-American family members and other informants are less likely than are their white counterparts to report mild cognitive impairment in people who are cognitively impaired but not demented (CIND), NIA-funded research shows. The finding suggests that cultural differences may influence informant reports of cognitive impairment in non-demented people.

    The analysis included 645 older African-American and white participants in the Aging, Demographics, and Memory Study, a subset of the NIA-funded Health and Retirement Study. Researchers compared results of both direct testing of participants and informant reports of participant cognition with clinical diagnoses of cognitive impairment and dementia. Informants completed the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE)—a widely used measure of cognitive decline, while participants were given clinical diagnoses of normal cognition, CIND, or dementia by an expert panel.

    Informant reports of higher cognitive decline, as measured by IQCODE scores, were associated with increased odds of dementia in both African Americans and whites. However, higher IQCODE scores were associated with increased odds of CIND diagnosis among whites but not among African Americans. For both African Americans and whites, a higher total score on another test, the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) measure, was associated with lower odds of CIND and dementia.

    The results suggest that African-American informants are less inclined than whites are to report mild cognitive changes, the authors explain. More comparative research is needed to establish the cultural validity of measures used to diagnose cognitive impairment, the researchers state.

    Reference:

    Potter, G.G., et al. Cognitive performance and informant reports in the diagnosis of cognitive impairment and dementia in African Americans and whites. Alzheimer's & Dementia. 2009. 5:445-53.

  • June 15, 2010

    A recent study examining predictors of participant dropout in a clinical trial of treatments for mild cognitive impairment (MCI) has found that participants recruited by NIA-funded Alzheimer's Disease Centers (ADCs) and university-affiliated sites have dramatically lower dropout rates than do those recruited by commercial sites. The authors of the study, including researchers in ADCs at the University of California, San Diego, and the Mayo Clinic, suggest that superior participant retention rates may translate into greater statistical power and validity of clinical trial results.

    A high number of dropouts during a trial can weaken the statistical power of a trial and make it more difficult to detect an effect. In addition, a high number of dropouts may bias results, because participants that drop out may be different (e.g., they may be sicker, etc.) from those who complete the trial.

    The Edland, et al., study identified several demographic parameters that, in addition to the trial site, predict a higher dropout rate. Some of these include marital status, education, and race/ethnicity. For example, lower education and non-white race were associated with higher dropout. The authors speculate that retention efforts targeting the identified subgroups may improve the validity and power of future trials.

    The authors offer several possible causes for the differences in subject retention between ADCs and university-affiliated trial sites compared to commercial sites. The authors note that commercial sites tend to recruit more subjects through advertising. ADCs and university-affiliated sites also recruit through advertising, but they recruit many participants from their clinic populations. Longstanding relationships among clinic staff and participants may improve retention. Moreover, people who respond to advertising may be more focused on receiving the active drug or treatment and be more likely to drop out if they believe they are receiving placebo, think the drug is not working, or it causes unwelcome side effects.

    Edland, S.D., et al. NIA-funded Alzheimer Centers are more efficient than commercial clinical recruitment sites for conducting secondary prevention trials of dementia. Alzheimer's Disease and Associated Disorders. 2010. 24(2):159-64.

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