Alzheimers

Alzheimer's & other dementias

Education gives an advantage that lasts a lifetime

A French study involving 36 healthy older adults (60-80), prescreened for amyloid deposits in the brain to exclude people who might have preclinical Alzheimer’s disease, has found a linear increase in gray matter volume in proportion to the number of years of education (7-20 years). Specifically, increases were seen in the right superior temporal gyrus, anterior cingulate gyrus, and left insular cortex, and metabolism also increased proportionately with years of education in the anterior cingulate gyrus, as did functional connectivity between anterior cingulate gyrus and the right hippocampus, left angular gyrus, right posterior cingulate, and left inferior frontal gyrus. This increased connectivity was associated with improved cognitive performance.

The conclusion is that both the structure of the brain and its function in old age are increased in proportion to the number of years of education.

http://blogs.scientificamerican.com/mind-guest-blog/2013/07/03/school-work-prevents-senile-dementia/

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High dose statins prevent dementia

Data from 57,669 older Taiwanese patients (65+) with no dementia at the beginning of the 5-year study has found that the risk of developing dementia was inversely related to statin dosage. Those on the highest doses of statins were three times less likely to develop dementia. The potency of the statins was also a factor, with high potency statins such as atorvastatin and rosuvastatin giving the most benefit.

Nearly 10% developed dementia during the study.

http://www.eurekalert.org/pub_releases/2013-08/esoc-hds083013.php

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“Statin use and the incidence of dementia in the elderly: a nation-wide data survey” was presented at the European Society of Cardiology 2013 Congress in Amsterdam.

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Better hygiene in wealthy nations may increase Alzheimer's risk

A comparison of Alzheimer’s prevalence across the world using 'age-standardized' data (which predict Alzheimer's rates if all countries had the same population birth rate, life expectancy and age structure) has found a strong correlation between national sanitation levels and Alzheimer's, with better hygiene associated with higher rates of Alzheimer’s.

This fits in with the idea that’s been floating around for a while, that over-sanitized environments reduce exposure to a diverse range of microorganisms, perhaps impairing proper development of the immune system. Hence, the rising incidence of allergies and auto-immune diseases in developed countries.

The study compared data from 192 countries. Higher rates of Alzheimer's were seen in countries with higher levels of sanitation, countries with much lower rates of infectious disease, and more urbanized countries. For example, UK and France have 9% higher Alzheimer's rates than Kenya and Cambodia; Switzerland and Iceland have 12% higher rates of Alzheimer's than China and Ghana; UK and Australia have 10% higher rates than Bangladesh and Nepal.

Differences in levels of sanitation, infectious disease and urbanization accounted respectively for 33%, 36% and 28% of the discrepancy in Alzheimer's rates between countries.

Previous research has shown that in the developed world, dementia rates doubled every 5.8 years compared with 6.7 years in low income, developing countries, and that Alzheimer's prevalence in Latin America, China and India are all lower than in Europe, and, within those regions, lower in rural compared with urban settings.

Having said all that, I would query the reliability of Alzheimer’s statistics from less developed countries. A recent study from China, for example, found dramatic under-reporting of Alzheimer’s. While this is certainly a plausible hypothesis, I think the wide variability in diagnosing Alzheimer’s stands in the way of this sort of comparison.

http://www.eurekalert.org/pub_releases/2013-09/uoc-bhi090413.php

http://www.theguardian.com/society/2013/sep/04/alzheimers-disease-link-hygiene

Full text freely available at http://emph.oxfordjournals.org/content/2013/1/173.full

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Gum disease may have ties to Alzheimer’s

Analysis of post-mortem with and without dementia has found lipopolysaccharide, a component of an oral bacterium (Porphyromonas gingivalis), in four out of 10 Alzheimer’s disease brain samples, but not in any of the 10 brains of people who didn’t have Alzheimer’s.

Gingivitis is extremely common, and about 64% of American seniors (65+) have moderate or severe periodontal disease.

The finding adds to evidence linking gum disease and Alzheimer’s.

http://www.futurity.org/alzheimers-may-ties-gum-disease/

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More evidence for a link between type 2 diabetes and Alzheimer’s

Glucose levels linked to cognitive decline in those with MCI

A study involving 264 older adults with mild cognitive impairment has found that those with normal glucose levels (167; 63%) had less cognitive decline over 2 years than those with impaired (high) glucose levels (97; 37%). They also showed less brain shrinkage and were less likely to develop Alzheimer’s. The fasting glucose levels were classified according to the American Diabetes criteria.

[3614] Vos, S JB., Xiong C., Visser P J., Jasielec M. S., Hassenstab J., Grant E. A., et al.
(2013).  Preclinical Alzheimer's disease and its outcome: a longitudinal cohort study.
The Lancet Neurology. 12(10), 957 - 965.

Rat study suggests cognitive decline in diabetics related to amyloid-beta buildup

A rat study supports the growing evidence of a link between type 2 diabetes and Alzheimer’s. In this study, 20 rats were fed a high-fat diet to give them type 2 diabetes. A subsequent test found that the diabetic rats had significantly poorer memories than the control group of rats on a healthy diet (the rats were taught to associate a dark cage with an electric shock; how long the rat continues to remember that the stimulus means a shock — as shown by their frozen reaction — is taken as a measure of how good their memory is; the diabetic rats froze for less than half the time of the controls).

The diabetic rats then had their brains (specifically, the hippocampus) injected with antibodies that disrupt amyloid-beta plaques. This produced no change in their behavior. However, when they were given antibodies that disrupt amyloid-beta oligomers (precursors of the plaques), the memory deficit was reversed, and they behaved the same as the healthy rats.

These findings suggest that the cognitive decline often seen in type 2 diabetes is not due to the disruption in insulin signaling, as thought, but rather the build-up of amyloid oligomers. Previous research has shown that the same enzymes break down both insulin and the oligomers, so when there’s a lot of insulin (which the enzymes prioritize), the enzymes don’t have as much opportunity to work on breaking down the oligomers. The oligomers collect, preventing the insulin from reaching their proper receptors in the hippocampus, which impairs cognitive function.

All this supports the idea that type 2 diabetes may be thought of as early-stage Alzheimer's. Obviously a lot more work needs to be done to confirm this picture, but certainly in the mean time, it can be taken as another reason to take type 2 diabetes very seriously.

www.newscientist.com/article/mg22029453.400-are-alzheimers-and-diabetes-the-same-disease.html

McNay, E.C., Osborne, D., et al. 2014. Preliminary data presented at the Society for Neuroscience meeting in San Diego in November, 2013

High blood sugar makes Alzheimer’s plaque more toxic

A study of cell cultures taken from rodents’ cerebral blood vessels has found that, while cells exposed to either high glucose or amyloid-beta showed no changes in viability, exposure to both decreased cell viability by 40%. Moreover, cells from diabetic mice were more vulnerable to amyloid-beta, even at normal glucose levels.

The findings support evidence pointing to high glucose as a risk factor for vascular damage associated with Alzheimer’s, and adds weight to the view that controlling blood sugar levels is vital for those with diabetes.

http://www.futurity.org/high-blood-sugar-makes-alzheimers-plaque-toxic/

[3558] Carvalho, C., Katz P. S., Dutta S., Katakam P. V. G., Moreira P. I., & Busija D. W.
(2014).  Increased Susceptibility to Amyloid-β Toxicity in Rat Brain Microvascular Endothelial Cells under Hyperglycemic Conditions.
Journal of Alzheimer's Disease. 38(1), 75 - 83.

Mechanism by which diabetes increases Alzheimer's risk revealed

Although it's well-established now that diabetes is a major risk factor for dementia, the reason is still not well understood. To test the hypothesis that epigenetic changes in the brain, affecting synaptic function, may be part of the reason, the brains of diabetics and others were examined post-mortem. Diabetics' brains were found to have significantly higher expression of a class of molecules (histone deacetylases class IIa) and this was associated with impaired expression of synaptic proteins.

This finding was confirmed in mice genetically engineered to develop an Alzheimer’s-type condition, who were induced to develop diabetes. The increase of HDAC IIa was associated with synaptic impairments in the hippocampus, through the work of amyloid oligomers.

Some 60% of Alzheimer's patients have at least one serious medical condition associated with diabetes.

http://www.eurekalert.org/pub_releases/2013-10/tmsh-cie102213.php

[3615] Wang, J., Gong B., Zhao W., Tang C., Varghese M., Nguyen T., et al.
(2014).  Epigenetic Mechanisms Linking Diabetes and Synaptic Impairments.
Diabetes. 63(2), 645 - 654.

High Blood Sugar Linked to Dementia

A seven-year study involving 2,067 older adults (average age 76 at start) has found that those with a high blood glucose level, whether or not they had diabetes, were more likely to develop dementia. Moreover, this was a linear relationship — meaning that the risk steadily increased with higher glucose levels, and decreased the lower it was. Thus, even those with ‘normal’ glucose levels were subject to this relationship, with those whose blood sugar averaged 115 milligrams per deciliter, having an 18% higher risk of dementia than those at 100 mg/dL. Other risk factors, such as high blood pressure, smoking, exercise, and education, were taken into account in the analysis.

The findings add weight to the idea that the brain is a target organ for damage by high blood sugar.

Over the course of the study, a quarter (524) developed dementia of some kind, primarily Alzheimer’s disease or vascular dementia. At the beginning of the study, 232 (11%) had diabetes, and a further 111 developed it by the end of the study. Nearly a third (32%) of those with diabetes at the beginning of the study developed dementia, compared to just under a quarter of those without (24.5%).

http://newoldage.blogs.nytimes.com/2013/08/09/high-blood-sugar-linked-to-dementia/

The journal article is freely available at http://www.nejm.org/doi/full/10.1056/NEJMoa1215740#t=article

[3563] Crane, P. K., Walker R., Hubbard R. A., Li G., Nathan D. M., Zheng H., et al.
(2013).  Glucose Levels and Risk of Dementia.
New England Journal of Medicine. 369(6), 540 - 548.

Undiagnosed pre-diabetes highly prevalent in early Alzheimer's disease

A study involving 128 patients with mild to moderate Alzheimer’s disease, which had specifically excluded those with known diabetes, found that 13% of them did in fact have diabetes, and a further 30% showed glucose intolerance, a pre-diabetic condition.

Turner presented his findings at the Alzheimer's Association International Congress in Boston on July 14.

http://www.eurekalert.org/pub_releases/2013-07/gumc-uph070513.php

Association between hypoglycemia, dementia in older adults with diabetes

A 12-year study involving 783 older adults with diabetes (average age 74) has found that 148 (19%) developed dementia. Those 61 patients (8%) who had a reported hypoglycemic event were twice as likely to develop dementia compared to those who didn’t suffer such an event (34% vs. 17%). Similarly, those with dementia were more likely to experience a severe hypoglycemic event.

The findings suggest some patients risk entering a downward spiral in which hypoglycemia and cognitive impairment fuel one another, leading to worse health

http://www.eurekalert.org/pub_releases/2013-06/tjnj-abh060613.php

http://www.eurekalert.org/pub_releases/2013-06/uoc--aal060613.php

[3622] Yaffe, K., CM F., N H., & et al
(2013).  ASsociation between hypoglycemia and dementia in a biracial cohort of older adults with diabetes mellitus.
JAMA Internal Medicine. 173(14), 1300 - 1306.

Dementia risk greatest for older Native-Americans and African-Americans with diabetes

In the first study to look at racial and ethnic differences in dementia risk among older adults with type 2 diabetes, Native Americans were 64% more likely to develop dementia than Asian-Americans, and African-Americans were 44% more likely. Asian-Americans had the lowest risk, and non-Hispanic whites and Latinos were intermediate.

The study involved 22,171 older adults (60+), of whom 3,796 patients (17%) developed dementia over the 10 years of the study. Almost 20% of the African-Americans and Native Americans developed dementia.

The ethnic differences were not explained by diabetes-related complications, glycemic control or duration of diabetes, or neighborhood deprivation index, body mass index, or hypertension.

http://www.eurekalert.org/pub_releases/2013-12/kp-drg121113.php

[3590] Mayeda, E. R., Karter A. J., Huang E. S., Moffet H. H., Haan M. N., & Whitmer R. A.
(2014).  Racial/Ethnic Differences in Dementia Risk Among Older Type 2 Diabetic Patients: The Diabetes and Aging Study.
Diabetes Care. 37(4), 1009 - 1015.

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Exercise beneficial for dementia

A new review from The Cochrane Library, based on six trials involving 289 people, has concluded that exercise can improve cognition and the ability of older people with dementia to carry out daily activities, such as walking short distances or getting up from a chair. However, there was no clear effect of exercise on depression in older people with dementia, and the reviewers say that more evidence is needed to understand how exercise could reduce the burden on family caregivers and health systems.

http://www.eurekalert.org/pub_releases/2013-12/w-ebf120313.php

Reference: 

Forbes D, Thiessen EJ, Blake CM, Forbes SC, Forbes S. Exercise programs for people with dementia. Cochrane Database of Systematic Reviews 2013, Issue 12. Art. No.: CD006489. DOI: 10.1002/14651858.CD006489.pub3.

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Mild Cognitive Impairment

Older news items (pre-2010) brought over from the old website

Specific hippocampal atrophy early sign of MCI & Alzheimer's

A three-year study involving 169 people with MCI has found that those who later developed Alzheimer's disease showed 10-30% greater atrophy in two specific locations within the hippocampus, the cornu ammonis (CA1) and the subiculum. A second study comparing the brains of 10 cognitively normal elderly people and seven who were diagnosed with MCI between two and three years after their initial brain scan and with Alzheimer's some seven years after the initial scan, has confirmed the same pattern of hippocampal atrophy, from the CA1 to the subiculum, and then other regions of the hippocampus.

Apostolova, L. G., Thompson, P. M., Green, A. E., Hwang, K. S., Zoumalan, C., Jr, C. R. J., Harvey, D. J., et al. (2010). 3D comparison of low, intermediate, and advanced hippocampal atrophy in MCI. Human Brain Mapping, 9999(9999), NA. doi:10.1002/hbm.20905

Apostolova, L.G. et al. In press. Subregional hippocampal atrophy predicts Alzheimer's dementia in the cognitively normal. Neurobiology of Aging, Available online 24 September 2008.

http://www.eurekalert.org/pub_releases/2010-01/uoc--uri012810.php

Characteristics of age-related cognitive decline in semantic memory

A study involving 117 healthy elderly (aged 60-91) has found that, while increasing age was associated with poorer memory for names of famous people, age didn’t affect memory for biographical details about them. It also found that names served as better cues to those details than faces did. A follow-up study (to be published in Neuropsychologia) found that, in contrast, those with mild cognitive impairment and early Alzheimer’s showed not only an increased inability to remember names, but also a decline in memory for biographical details.

Langlois, R. et al. 2009. Manque du nom propre et effet de la modalité sur la capacité à reconnaître des personnes connues au cours du vieillissement normal. Canadian Journal on Aging/ La Revue canadienne du vieillissement, 28 (4), 337-345.

http://www.eurekalert.org/pub_releases/2009-12/uom-whn121809.php

Apathy common in dementia patients with white matter changes

A study involving 176 patients with Alzheimer's, vascular dementia or mixed dementia, or mild cognitive impairment, has found that 82% of the patients with changes in their white matter were apathetic, compared to an overall rate of 58%. This discovery suggests that there is a common biological reason behind this apathy, irrespective of which type of dementia a patient has. White matter changes were also associated with age, gender, blood pressure, hypertension, ischaemic heart disease, mental slowness, disinhibition, gait disturbance and focal neurologic symptoms. Apathy, mental slowness and age were the most consistent predicting factors for WMCs.

Jonsson, M., Edman, Å., Lind, K., Rolstad, S., Sjögren, M., & Wallin, A. (2009). Apathy is a prominent neuropsychiatric feature of radiological white-matter changes in patients with dementia. International Journal of Geriatric Psychiatry, 9999(9999), n/a. doi: 10.1002/gps.2379.

http://www.eurekalert.org/pub_releases/2009-12/uog-aci120209.php

Difficulties with daily activities associated with progression to dementia

A study involving 111 older adults with mild cognitive impairment, of whom 28 progressed from mild cognitive impairment to dementia over the next 2 ½ years, found only one factor predicted conversion from mild cognitive impairment to dementia: the degree of functional impairment (ability to perform routine activities) at the beginning of the study. Other cognitive and neurological variables were not predictive.

Farias, S.T. et al. 2009. Progression of Mild Cognitive Impairment to Dementia in Clinic- vs Community-Based Cohorts. Archives of Neurology, 66(9), 1151-1157.

http://www.eurekalert.org/pub_releases/2009-09/jaaj-dwd091009.php

Problems managing money may be early sign of Alzheimer's

A study involving 76 older people with no memory problems and 87 older people with amnestic mild cognitive impairment has found that those (25 of the 87) who had developed Alzheimer’s a year later were significantly worse at a money management task. Compared to those with no memory problems, as well as those with MCI who did not develop dementia, those who did develop Alzheimer’s not only dropped 9% on checkbook management abilities and 6% on overall financial knowledge and skills, but also performed more poorly at the beginning of the study. The task included counting coins, making grocery purchases, understanding and using a checkbook, understanding and using a bank statement, preparing bills for mailing, and detecting fraud situations.

Triebel, K.L. et al. 2009. Declining financial capacity in mild cognitive impairment: A 1-year longitudinal study. Neurology, 73, 928-934.

http://www.eurekalert.org/pub_releases/2009-09/aaon-pmm091509.php
http://www.eurekalert.org/pub_releases/2009-09/uoaa-pmm091609.php

Different effects of ministrokes & strokes

A study involving 679 seniors (65+) has found that those with small areas of brain damage called white matter hyperintensities, often referred to as ministrokes, were nearly twice as likely to have mild cognitive impairment that included memory loss (amnestic MCI), while those who had infarcts (areas of dead tissue usually called strokes) were more likely to experience mild cognitive impairment in abilities other than memory loss (non-amnestic MCI). In other words, ministrokes predicted memory problems, while strokes predicted non-memory problems.

Luchsinger, J.A. et al. 2009. Subclinical cerebrovascular disease in mild cognitive impairment. Neurology, 73, 450-456.

http://www.eurekalert.org/pub_releases/2009-08/aaon-bds080409.php

White matter changes may predict dementia risk

In a study in which 49 seniors (65+) were followed for an average of 9.5 years, of whom 24 developed mild cognitive impairment, those with the fastest rate of growth in white matter lesions were more likely to develop mild cognitive impairment than those with a slow rate of growth. The amount of lesions in healthy brains at the start of the study was not a factor; the crucial factor was the rate of progression.

Silbert, L.C. et al. 2009. Cognitive impairment risk: White matter hyperintensity progression matters. Neurology, 73, 120-125.

http://www.eurekalert.org/pub_releases/2009-07/aaon-wmc070709.php

Measuring brain atrophy in patients with mild cognitive impairment

A study involving 269 patients with mild cognitive impairment provides evidence that a fully automated procedure called Volumetric MRI (that can be done in a clinical setting) can accurately and quickly measure parts of the medial temporal lobe and compare them to expected size. It also found that not only atrophy in the hippocampus but also the amygdala is associated with a greater risk of conversion to Alzheimer’s.

Kovacevic, S. et al. 2009. High-throughput, Fully Automated Volumetry for Prediction of MMSE and CDR Decline in Mild Cognitive Impairment. Alzheimer Disease & Associated Disorders, 23 (2), 139-145.

http://www.eurekalert.org/pub_releases/2009-06/uoc--mba061609.php

Cerebrospinal fluid shows Alzheimer's disease deterioration much earlier

A study involving 60 patients with subjective cognitive impairment, 37 patients with non-amnestic mild cognitive impairment, and 71 with amnestic mild cognitive impairment, has found that 52% of those with SCI, 68% of those with naMCI, and 79% of those with aMCI showed decreased concentrations of Aβ42 and increased concentrations of tau protein in the cerebrospinal fluid. The findings confirm the use of biomarkers in the CSF for very early diagnosis.

Visser, P.J. et al. 2009. Prevalence and prognostic value of CSF markers of Alzheimer's disease pathology in patients with subjective cognitive impairment and mild cognitive impairment in the DESCRIPA study: a prospective, case-control study. The Lancet Neurology, 8 (7), 619–627.

http://www.eurekalert.org/pub_releases/2009-06/uog-cfs061809.php

Effective new cognitive screening test for detection of Alzheimer's

A new cognitive test for detecting Alzheimer's has been developed, and designed to be suitable for non-specialist use. The TYM ("test your memory") involves 10 tasks including ability to copy a sentence, semantic knowledge, calculation, verbal fluency and recall ability. It has been tested on 540 healthy individuals and139 patients with diagnosed Alzheimer's or mild cognitive impairment. Healthy controls completed the test in an average time of five minutes and gained an average score of 47 out of 50, compared to 45 for those with mild cognitive impairment, 39 for those with non-Alzheimer dementias and 33 for those with Alzheimer’s. Among controls, the average score was not affected by age until after 70, when it showed a small decline. There were no gender or geographical background differences in performance. The TYM detected 93% of patients with Alzheimer's, compared to only 52% by the widely used mini-mental state examination.

Brown, J. et al. 2009. Self administered cognitive screening test (TYM) for detection of Alzheimer’s disease: cross sectional study. BMJ, 338:b2030, doi: 10.1136/bmj.b2030 Full text available here.

Eye tracking test detects mild cognitive impairment

A test first developed for use with nonhuman primates is now being used to detect mild cognitive impairment (MCI) in humans. The infrared eye-tracking test involves showing one image and then another after a 2-second delay, and then repeating the test 2 minutes later. Those without cognitive impairment spend most of their time looking at the new image, but it was found that those with MCI spent less time looking at the new picture, presumably because they have less memory of seeing the original image before. Those with Alzheimer's disease look at both images equally. It’s hoped that this test may allow dementia to be spotted much earlier.

Crutcher, M.D. et al. 2009. Eye Tracking During a Visual Paired Comparison Task as a Predictor of Early Dementia. American Journal of Alzheimer's Disease and Other Dementias, Published online February 26 2009.

http://www.eurekalert.org/pub_releases/2009-04/eu-yru041509.php

Biomarker signatures predict conversion from MCI to Alzheimer's

Cerebrospinal fluid samples from 410 volunteers (100 with mild Alzheimer’s; 196 with MCI; 114 cognitively normal older adults) has revealed that concentrations of amyloid beta-42 peptide and tau protein successfully assessed brain status and predicted development. The test diagnosed Alzheimer’s with 96% accuracy; ruled out Alzheimer’s with 95% accuracy; and predicted the conversion from MCI to Alzheimer’s with 82% accuracy.

Shaw, L.M. et al. 2009. Cerebrospinal fluid biomarker signature in Alzheimer's disease neuroimaging initiative subjects. Annals of Neurology, Published Online March 18 2009.

http://www.eurekalert.org/pub_releases/2009-03/uops-pmp031609.php

Less risk of developing dementia than thought

Data from 41 studies has revealed the risk of those with mild cognitive impairment developing dementia is much less than thought. MCI is found in about 1 in 6 people seen in general practice, and it was thought that the risk of developing dementia was up to 15% per year, making deterioration almost inevitable within 5 to 10 years. It now appears that the risk is 10% per year in high risk groups (9.6% for dementia overall; 8% for Alzheimers; 2% for vascular dementia) and only 5% per year in low risk groups (5% for dementia overall; 7% for Alzheimers; 1.6% for vascular dementia). More importantly, only 20-40% developed dementia even after 10 years and the risk appeared to reduce slightly with time.

Mitchell, A.J. & Shiri-Feshki, M. 2009. Rate of progression of mild cognitive impairment to dementia – meta-analysis of 41 robust inception cohort studies. Acta Psychiatrica Scandinavica, 119 (4), 252-265.

http://www.eurekalert.org/pub_releases/2009-03/uol-nrh032309.php

Brain atrophy pattern in some MCI patients predicts Alzheimer's

A study of 84 patients with mild Alzheimer's, 175 patients with MCI and 139 healthy controls has revealed a pattern of regional brain atrophy in patients with MCI that indicates a greater likelihood of progression to Alzheimer's. Brain scans results showed widespread cortical atrophy in some patients with MCI, most importantly, atrophy in parts of the medial and lateral temporal lobes and in the frontal lobes — a pattern also present in the patients with mild Alzheimer's disease. Those exhibiting such atrophy declined significantly over a year and were more likely to progress to a probable diagnosis of Alzheimer's. MCI patients without that pattern of atrophy remained stable after a year. It should be noted that such atrophy affects not only memory, but also planning, organization, problem solving and language.

McEvoy, L.K. et al. 2009. Alzheimer Disease: Quantitative Structural Neuroimaging for Detection and Prediction of Clinical and Structural Changes in Mild Cognitive Impairment. Radiology, Published online February 6.

http://www.eurekalert.org/pub_releases/2009-02/rson-msb020309.php

Technique shows brain aging before symptoms appear

A new chemical marker called FDDNP, which binds to plaque and tangle deposits in the brain, has enabled PET scans to reveal exactly where these abnormal protein deposits are accumulating, and has found that older age correlated with higher concentrations of FDDNP in the medial and lateral temporal regions of the brain, areas involved with memory, where plaques and tangles usually collect. Of the 76 study volunteers, 34 carried the ‘Alzheimer’s gene’. This group demonstrated higher FDDNP levels in the frontal region of the brain than those without the gene variant. Thirty-six of the volunteers had mild cognitive impairment, and these had higher measures of FDDNP in the medial temporal brain regions than normal volunteers. Those who had both MCI and the APOE-4 gene also had higher concentrations of FDDNP in the medial temporal brain regions than those who had MCI but not APOE-4. The pilot study offers hope of early diagnosis of brain impairment, before symptoms show themselves.

Small, G.W. et al. 2009. Influence of Cognitive Status, Age, and APOE-4 Genetic Risk on Brain FDDNP Positron-Emission Tomography Imaging in Persons Without Dementia. Archives of General Psychiatry, 66(1), 81-87.

http://www.eurekalert.org/pub_releases/2009-01/uoc--uat010509.php

Occasional memory loss tied to lower brain volume

A study of 503 seniors (aged 50-85) with no dementia found that 453 of them (90%) reported having occasional memory problems such as having trouble thinking of the right word or forgetting things that happened in the last day or two, or thinking problems such as having trouble concentrating or thinking more slowly than they used to. Such problems have been attributed to white matter lesions, which are very common in older adults, but all of the participants in the study had white matter lesions in their brains, and the amount of lesions was not tied to occasional memory problems. However it was found that those who reported having such problems had a smaller hippocampus than those who had no cognitive problems. This was most noteworthy in subjects with good objective cognitive performance.

van Norden, A.G.W. et al. 2008. Subjective cognitive failures and hippocampal volume in elderly with white matter lesions. Neurology, 71, 1152-1159.

http://www.eurekalert.org/pub_releases/2008-10/aaon-oml093008.php

Moderate exercise helps mild cognitive impairment

An Australian study involving 138 older adults (50 years and over) with mild cognitive impairment, has found that those who undertook to achieve 2 ½ hours of physical activity each week (three 50 minute sessions), ranging from walking, ballroom dancing to swimming, for a six month period, continually out-scored the control group on cognitive tests during the 18 month testing period — showing that memory improvement was still evident a year after the supervised exercise period.

Lautenschlager, N.T. et al. 2008. Effect of Physical Activity on Cognitive Function in Older Adults at Risk for Alzheimer Disease: A Randomized Trial. Journal of the American Medical Association, 300(9), 1027-1037.

http://www.eurekalert.org/pub_releases/2008-09/ra-wtp090108.php
http://www.eurekalert.org/pub_releases/2008-09/uom-aow090108.php
http://www.eurekalert.org/pub_releases/2008-09/jaaj-emh082808.php

New 'everyday cognition' scale tracks how older adults function in daily life

A new, carefully validated questionnaire called Everyday Cognition (ECog) has been developed by seven psychologists. The 39-question screening tool is designed to enable mild functional problems in older adults to be quickly and easily identified. The questionnaire needs to be filled out by someone who knows an older adult well, such as a spouse, adult child, or close friend. It looks at everyday function in seven key cognitive domains: memory, language, semantic (factual) knowledge, visuospatial abilities, planning, organization and divided attention. The test has been shown to be sensitive to early changes present in Mild Cognitive Impairment, and unlike other cognitive tests, does not appear to be strongly influenced by education level. The test even differentiated between people diagnosed with mild impairment in memory only and those mildly impaired in several areas.

Farias, S.T. et al. 2008. The Measurement of Everyday Cognition (ECog): Scale Development and Psychometric Properties. Neuropsychology, 22 ( 4), 531-544.

http://www.eurekalert.org/pub_releases/2008-07/apa-nc062408.php

Mild cognitive impairment more likely in men

A study involving over 2000 people between 70 and 89 years old, found 15% had mild cognitive impairment, and men were one-and-a-half times more likely to have MCI than women.

The research was presented at the American Academy of Neurology Annual Meeting in Chicago, April 12–19.

http://www.eurekalert.org/pub_releases/2008-04/aaon-mml040208.php

High blood pressure associated with risk for mild cognitive impairment

A study of nearly 1000 older adults (average age 76.3) without mild cognitive impairment at the start of the study found that over the follow-up period (average: 4.7 years), 334 individuals developed mild cognitive impairment, of which 160 were amnestic (reduced memory) and 174 were non-amnestic. Hypertension (high blood pressure) was associated with an increased risk of non-amnestic mild cognitive impairment; but not with amnestic mild cognitive impairment.

Reitz, C. et al. 2007. Hypertension and the Risk of Mild Cognitive Impairment. Archives of Neurology, 64(12), 1734-1740.

http://www.eurekalert.org/pub_releases/2007-12/jaaj-hbp120607.php

Difficulty identifying odors may predict cognitive decline

Older adults who have difficulty identifying common odors may have a greater risk of developing mild cognitive impairment, increasingly recognized as a precursor to Alzheimer’s disease.  A study of nearly 600 older adults (average age 79.9) found that 30.1% developed mild cognitive impairment over the five-year period of the study. Risk of developing mild cognitive impairment was greater for those who scored worse on an odor identification test given at the start of the study. For example, those who scored below average (eight) were 50% more likely to develop MCI than those who scored above average (11). This association did not change when stroke, smoking habits or other factors that might influence smell or cognitive ability were considered. Impaired odor identification was also associated with lower cognitive scores at the beginning of the study and with a more rapid decline in episodic memory (memory of past experiences), semantic memory (memory of words and symbols) and perceptual speed. The odor test involved identifying 12 familiar odors given four possible alternatives to choose from.

Wilson, R.S., Schneider, J.A., Arnold, S.E., Tang, Y., Boyle, P.A. & Bennett, D.A. 2007. Olfactory Identification and Incidence of Mild Cognitive Impairment in Older Age. Archives of General Psychiatry, 64, 802-808.

http://www.eurekalert.org/pub_releases/2007-07/jaaj-dio062807.php

Senior’s memory complaints should be taken seriously

A study involving 120 people over 60 found those who complained of significant memory problems who still performed normally on memory tests had a 3% reduction in gray matter density in their brains. This compares to 4% in those diagnosed with mild cognitive impairment. This suggests that significant memory loss complaints may indicate a very early "pre-MCI" stage of dementia for some people.

Saykin, A.J. et al. 2006. Older adults with cognitive complaints show brain atrophy similar to that of amnestic MCI. Neurology, 67, 834-842.

http://www.eurekalert.org/pub_releases/2006-09/aaon-fym090506.php

Link between size of hippocampus and progression to Alzheimer's

A study of 20 older adults with mild cognitive impairment has found that the hippocampus was smaller in those who developed into Alzheimer's during the 3 year period.

Apostolova, L.G. et al. 2006. Conversion of Mild Cognitive Impairment to Alzheimer Disease Predicted by Hippocampal Atrophy Maps. Archives of Neurology, 63, 693-699.

http://www.eurekalert.org/pub_releases/2006-05/uoc--rml050406.php

Post-mortem brain studies reveal features of mild cognitive impairment

Autopsies have revealed that the brains of patients with mild cognitive impairment display pathologic features that appear to place them at an intermediate stage between normal aging and Alzheimer's disease. For instance, the patients had begun developing neurofibrillary tangles, but the number of plaques was similar to that in healthy patients. All patients with mild cognitive impairment had abnormalities in their temporal lobes, which likely caused their cognitive difficulties, and many also had abnormalities in other areas that did not relate to the features of Alzheimer's disease. In a second study, of 34 patients with mild cognitive impairment who had progressed to clinical dementia before their deaths, 24 were diagnosed (post-mortem) with Alzheimer’s, and 10 with other types of dementia. As in the other study, all patients had abnormalities in their temporal lobes.

Petersen, R.C. et al. 2006. Neuropathologic Features of Amnestic Mild Cognitive Impairment. Archives of Neurology, 63, 665-672.

Jicha, G.A. et al. 2006. Neuropathologic Outcome of Mild Cognitive Impairment Following Progression to Clinical Dementia. Archives of Neurology, 63, 674-681.

http://www.eurekalert.org/pub_releases/2006-05/jaaj-pbs050406.php

Risk of mild cognitive impairment increases with less education

A study of 3,957 people from the general population of Olmsted County, Minnesota is currently in train to find how many of those who did not have dementia might have mild cognitive impairment. A report on the findings so far suggests 9% of those aged 70 to 79 and nearly 18% of those 80 to 89 have MCI. Prevalence varied not only with age but also years of education: 25% in those with up to eight years of education, 14% in those with nine to 12 years, 9% in those with 13 to 16 years, and 8.5% in those with greater than 16 years.

Findings from this study were presented April 4 at the American Academy of Neurology meeting in San Diego.

http://www.eurekalert.org/pub_releases/2006-04/mc-mci033006.php

Two pathways lead to Alzheimer's disease

Mild cognitive impairment (MCI), a transitional stage between normal cognition and Alzheimer's disease, has been categorized into two sub-types on the basis of differing symptoms. Those with the amnesic subtype (MCI-A) have memory impairments only, while those with the multiple cognitive domain subtype (MCI-MCD) have other types of mild impairments, such as in judgment or language, and mild or no memory loss. Both sub-types progress to Alzheimer's disease at the same rate. A new imaging technique has now revealed that these types do in fact have different pathologies. The hippocampus of patients with MCI-A was not significantly different from that of Alzheimer's patients (who show substantial shrinkage), but the hippocampus of those with MCI-MCD was not significantly different from that of the healthy controls.

Becker, J.T. et al. 2006. Three-dimensional Patterns of Hippocampal Atrophy in Mild Cognitive Impairment. Archives of Neurology, 63, 97-101.

http://www.eurekalert.org/pub_releases/2006-01/uopm-tpf010606.php

Concussions increase chance of age-related cognitive impairment

A study involving retired National Football League players found that they had a 37% higher risk of Alzheimer's than other U.S. males of the same age. Some 60.8% of the retired players reported having sustained at least one concussion during their professional playing career, and 24% reported sustaining three or more concussions. Those with three or more concussions had a five-fold greater chance of having been diagnosed with mild cognitive impairment and a three-fold prevalence of reported significant memory problems compared to those players without a history of concussion. As the study was based on self-reported answers to the health questions, further studies are needed to confirm the findings, but it does seem likely that head injuries earlier in life increase the chance of developing dementia or mild cognitive impairment.

Guskiewicz, K.M., Marshall, S.W., Bailes, J., McCrea, M., Cantu, R.C., Randolph, C. & Jordan, B.D. 2005. Association between Recurrent Concussion and Late-Life Cognitive Impairment in Retired Professional Football Players. Neurosurgery, 57(4), 719-726.

http://www.eurekalert.org/pub_releases/2005-10/uonc-nsa101005.php

New computer program may enable early prediction of Alzheimer's risk

Researchers have developed a brain scan-based computer program that quickly and accurately measures metabolic activity in the hippocampus, a key brain region that shrinks with the development of Alzheimer’s. The study followed 53 normal subjects aged 54 to 80 for at least 9 years and in some cases for as long as 24 years, and found that hippocampal glucose metabolism was significantly reduced on the first scan of those 25 individuals who would later experience cognitive decline related to either mild cognitive impairment or to Alzheimer's. The findings bring hope of being able to predict who will develop Alzheimer’s at least 9 years ahead of symptoms.

Mosconi, L., Tsui, W-H., De Santi, S., Li, J., Rusinek, H., Convit, A., Li, Y., Boppana, M. & de Leon, M.J. 2005. Reduced hippocampal metabolism in MCI and AD: Automated FDG-PET image analysis. Neurology, 64, 1860-1867.

http://www.eurekalert.org/pub_releases/2005-06/nyum-ncp061505.php

Rate of brain volume loss predicts dementia

A new study has found that rates of total brain volume loss may help identify patients with mild cognitive impairment who are at high risk of developing dementia. The study followed 55 people over 14 years, and found that loss of volume in the hippocampus predicted which mildly cognitively impaired individuals would stay stable and which would decline to Alzheimer's with 70% accuracy, while the rate of total brain volume loss was 62% accurate in predicting cognitive outcome. Combining both variables produced the strongest model: 75% accuracy. The discovery could help doctors plan early treatment strategies and prevention studies.

The study was presented at the 56th annual meeting of the American Academy of Neurology in San Francisco.

http://www.eurekalert.org/pub_releases/2004-04/ohs-osr042804.php

More sensitive test norms better predict who might develop Alzheimer's disease

Early diagnosis of Alzheimer's is becoming more important with new medical and psychological interventions that can slow (but not stop) the course of the disease. Given this, it is suggested that more sensitive testing may be necessary for highly intelligent people, who, on average, show clinical signs of Alzheimer's later than the general population. Once they show such signs, they decline much faster. A study of 42 older people with IQ's of 120 or more, used two different test norms to forecast problems: the standard norm, derived from a large cross-section of the population, or an adjusted high-IQ norm that measured changes against the individual's higher ability level. The raised cutoffs predicted that 11 of the 42 individuals were at risk for future decline – compared with standard cutoffs, which indicated they were normal. True to the former prediction, three and a half years later, nine of those 11 people had declined. Six of those went on to develop mild cognitive impairment (MCI), a transitional illness from normal aging to a dementia (of which one type is Alzheimer's). Five of these individuals have since received a diagnosis of Alzheimer's disease, two years after this study was submitted. It is also suggested that, at the other end of the scale, those with below-average intelligence have the potential for being misdiagnosed as 'demented' when they are not, and the norms should be adjusted downwards accordingly.

Rentz, D.M., Huh, T.J., Faust, R.R., Budson, A.E., Scinto, L.F.M., Sperling, R.A. & Daffner, K.R. 2004. Use of IQ-Adjusted Norms to Predict Progressive Cognitive Decline in Highly Intelligent Older Individuals. Neuropsychology, 18 (1).

http://www.eurekalert.org/pub_releases/2004-01/apa-mst122903.php

Brief telephone questionnaire screens for early signs of dementia

Researchers have developed a brief telephonic questionnaire that helps distinguish between persons with early signs of dementia and persons with normal cognitive function. The questionnaire provides a way to reach out to persons with dementia whose impairment otherwise may go undetected until substantial cognitive deterioration has occurred. The questionnaire consists of a test of delayed recall and 2 questions that ask whether the person needs help with remembering to take medications or with planning a trip for errands. It is estimated that of 100 people who score positive on this test, 42 will actually have cognitive impairment. In other words, this does not provide a diagnosis of Alzheimer’s, but provides evidence that further evaluation is required. The rate of false positives compares favorably to other types of screening tests. A further study is underway to confirm the validity and reliability of the test.

Fillit, H. et al. 2003. A Brief Telephonic Instrument to Screen for Cognitive Impairment in a Managed Care Population. Journal of Clinical Outcomes Management, , 419-429.

http://www.eurekalert.org/pub_releases/2003-09/twc-btq091603.php

Early diagnosis of Alzheimer's

An analysis of data from 40 participants enrolled in a long-term study at the UCSD Alzheimer’s Disease Research Center (ADRC) found that "paper-and-pencil" cognitive skills tests administered to normal subjects averaging 75 years of age contained early signs of cognitive decline in those subjects who later developed Alzheimer’s disease. All participants were symptom-free when they took the test. The differences were quite subtle - only some performance measures were affected.

http://www.eurekalert.org/pub_releases/2002-04/uoc--trs040502.php

Brain scans predict cognitive impairment

A three-year study of 48 healthy people from 60 to 80 years old, by New York University School of Medicine researchers, predicted which healthy elderly men and women would develop memory impairment based on scans of their brains. At the beginning of the study, everyone scored within the normal range on a battery of tests typically used to detect early loss of memory and other mental skills. However, PET scans revealed a reduction in glucose metabolism in an area of the brain called the entorhinal cortex among 12 people. Three years later, 11 of these people had experienced mild cognitive impairment and one had developed Alzheimer's disease. "Our work extends the use of PET scanning to identifying in normal aging subjects the earliest metabolic abnormalities that may lead to the memory losses referred to as mild cognitive impairment (MCI). The diagnosis of MCI carries a high risk for future Alzheimer's disease."

The study is published in the September 11 issue of The Proceedings of the National Academy of Sciences.

http://www.eurekalert.org/pub_releases/2001-09/nyum-bps090701.php

 

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These 5 healthy habits reduce dementia risk

There are five healthy behaviors that appear to significantly reduce the risk of dementia,

A 35-year study that monitored the healthy behaviors of 2,235 Welsh men aged 45 to 59 at the beginning of the study has found that those who consistently followed at least four of these five healthy behaviors — regular exercise, no smoking, acceptable BMI, high fruit and vegetable intake, and low/moderate alcohol intake — experienced a 60% reduction in dementia and cognitive decline compared with people who followed none. They also had 70% fewer instances of diabetes, heart disease, and stroke,.

Exercise was the most important of these factors.

Only 5% of the men were living a healthy lifestyle (i.e., following at least 4 of these healthy behaviors). Just under half of the 2235 men were non-smokers (46%), and around a third (35%) had an acceptable BMI. Only 15 men ate their “5+” daily (!!), so the requirement was reduced to only three or more portions of fruit and vegetables, enabling 18% to reach it. 39% exercised regularly and 59% reported alcohol intake within the guidelines. Only two men managed five healthy behaviors, and 109 managed four; 19% managed three; 36% two; 31% one; 8% couldn’t manage any.

http://www.futurity.org/five-healthy-behaviors-can-reduce-dementia-risk/

http://www.eurekalert.org/pub_releases/2013-12/cu-3ys120913.php

Reference: 

Elwood, P., Galante, J., Pickering, J., Palmer, S., Bayer, A., Ben-Shlomo, Y., … Gallacher, J. (2013). Healthy Lifestyles Reduce the Incidence of Chronic Diseases and Dementia: Evidence from the Caerphilly Cohort Study. PLoS ONE, 8(12), e81877. doi:10.1371/journal.pone.0081877

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Exercise helps MCI

A pilot study involving 17 older adults with mild cognitive impairment and 18 controls (aged 60-88; average age 78) has found that a 12-week exercise program significantly improved performance on a semantic memory task, and also significantly improved brain efficiency, for both groups.

The program involved treadmill walking at a moderate intensity. The semantic memory tasks involved correctly recognizing names of celebrities well known to adults born in the 1930s and 40s (difficulty in remembering familiar names is one of the first tasks affected in Alzheimer’s), and recalling words presented in a list. Brain efficiency was demonstrated by a decrease in the activation intensity in the 11 brain regions involved in the memory task. The brain regions with improved efficiency corresponded to those involved in Alzheimer's disease, including the precuneus region, the temporal lobe, and the parahippocampal gyrus.

Participants also improved their cardiovascular fitness, by about 10%.

http://www.eurekalert.org/pub_releases/2013-07/uom-emb073013.php

Reference: 

Smith, J.C. et al. 2013. Semantic Memory Functional MRI and Cognitive Function After Exercise Intervention in Mild Cognitive Impairment. Journal of Alzheimer’s Disease, 37 (1), 197-215.

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