Older news items (pre-2010) brought over from the old website
More evidence bypass surgery not responsible for cognitive impairment
A 6-year study of 326 heart patients has found no differences in brain impairment between those who had on-pump coronary artery bypass surgery (152 patients), off-pump bypass surgery patients (75 patients), and those who had drugs and arterial stents to keep their blood vessels open instead of bypass surgery (99 patients). However, all of them were found to have experienced significant cognitive decline over the six-year study period on tests of verbal memory, visual memory, visuoconstruction, language, motor speed, psychomotor speed, attention, and executive function, when compared to 69 heart-healthy people who had no known risk factors for coronary artery disease. The findings provide more evidence that it is the disease and not the surgery that causes long-term cognitive problems.
Selnes, O.A. et al. 2009. Do Management Strategies for Coronary Artery Disease Influence 6-Year Cognitive Outcomes? Annals of Thoracic Surgery, 88, 445-454.
http://www.eurekalert.org/pub_releases/2009-08/jhmi-itl080309.php
Heart failure linked to cognitive impairment
A study of 50 patients with chronic heart failure, matched with 50 people without HF, has found that patients with HF scored significantly lower than controls on 14 of 19 cognitive tests, and 46% of the HF patients were rated as having mild to severe cognitive impairment, compared to 16% of mild impairment in controls. The degree of cognitive impairment was closely related to the number of myocardial infarctions experienced. These findings have important implications for the care of patients with HF.
Sauvé, M.J. et al. 2009. Cognitive Impairments in Chronic Heart Failure: A Case Controlled Study. Journal of Cardiac Failure, 15 (1), 1-10.
http://www.eurekalert.org/pub_releases/2009-02/e-hfl020509.php
Heart disease linked to worse cognition
Another report has come out from the large Whitehall study, this time on the subject of coronary heart disease and cognition. The study found that coronary heart disease was associated with a worse performance in mental processes such as reasoning, vocabulary and verbal fluency, and that the longer ago the heart disease had been diagnosed, the worse was the person's cognitive performance. This effect was particularly marked in men. Although there has been quite a lot of research on cardiovascular disease and impaired cognition, this is the first, large study to specifically examine the association between coronary heart disease and cognition. The major risk factors for coronary heart disease are all modifiable: cigarette smoking, diabetes, high cholesterol levels and high blood pressure. The findings also support the growing view that it is events happening in earlier life that have an impact on whether or not dementia develops in older age.
Singh-Manoux, A. et al. 2008. History of coronary heart disease and cognitive performance in midlife: the Whitehall II study. European Heart Journal, Advance Access published on July 22, 2008
http://www.eurekalert.org/pub_releases/2008-07/esoc-hdi072108.php
Long-term cognitive decline in bypass patients not due to surgery
Another study has come out supporting the view that coronary bypass patients have no greater risk of long-term cognitive decline than patients not undergoing surgery. The study involved 152 patients who had bypass surgery and 92 patients with coronary artery disease who did not have surgical intervention. Patients had memory and other cognitive tests at the beginning of the study period, and after 3, 12, 36 and 72 months. The results showed that there were no significant differences in cognitive scores between the two groups at the beginning of the study. Both groups showed modest decline in cognitive performance during the study period, but there were no significant differences in the degree of decline between the groups after six years. It was suggested that the decline in both groups was related to the presence of risk factors for vascular disease.
Selnes, O.A. et al. 2008. Cognition 6 Years After Surgical or Medical Therapy for Coronary Artery Disease. Annals of Neurology, 63, 581-590.
http://www.eurekalert.org/pub_releases/2008-05/w-lcd051908.php
http://www.eurekalert.org/pub_releases/2008-05/jhmi-bnt051908.php
Stroke risk factors may signal faster cognitive decline in elderly
Analysis of the stroke risks of over 17,000 people aged 45 and older (average 65.9) has found that a higher stroke risk score was associated with a significantly higher rate of cognitive decline. The study also identified three specific risk factors significantly associated with memory loss – high systolic blood pressure, diabetes, and left ventricular hypertrophy.
The findings were reported at the American Stroke Association’s International Stroke Conference 2008.
http://www.eurekalert.org/pub_releases/2008-02/aha-srf021408.php
Review supports link between lifestyle factors and cognitive function in older adults
A review of 96 papers involving 36 very large, ongoing epidemiological studies in North America and Europe looking at factors involved in maintaining cognitive and emotional health in adults as they age has concluded that controlling cardiovascular risk factors, such as reducing blood pressure, reducing weight, reducing cholesterol, treating (or preferably avoiding) diabetes, and not smoking, is important for maintaining brain health as we age. The link between hypertension and cognitive decline was the most robust across studies. They also found a consistent close correlation between physical activity and brain health. However, they caution that more research is needed before specific recommendations can be made about which types of exercise and how much exercise are beneficial. They also found protective factors most consistently reported for cognitive health included higher education level, higher socio-economic status, emotional support, better initial performance on cognitive tests, better lung capacity, more physical exercise, moderate alcohol use, and use of vitamin supplements. Psychosocial factors, such as social disengagement and depressed mood, are associated with both poorer cognitive and emotional health in late life. Increased mental activity throughout life, such as learning new things, may also benefit brain health.
Hendrie, H.C. et al. 2006. The NIH Cognitive and Emotional Health Project: Report of the Critical Evaluation Study Committee. Alzheimer's & Dementia, 2(1), 12-32.
http://www.eurekalert.org/pub_releases/2006-02/aa-nss021606.php
Why cardiac arrest may hinder ability to learn certain tasks
Cardiac arrest can take a particularly harsh toll on the hippocampus, the area of the brain that plays a critical role in memory and navigation. A new mouse study found that mice that had had a (surgically induced) heart attack had far more difficulty learning a new spatial task than did healthy mice (controls were given the surgery, but didn’t have a cardiac arrest induced). Mice in the heart attack group spent about eight minutes in cardiac arrest – enough time to stop the flow of oxygen to the brain. Analysis of the brain tissue found an overall 18% decrease in dendritic spine density in the hippocampus in the cardiac arrest mice compared to the control mice (dendritic spines are projections from neurons involved in sending signals throughout the central nervous system and the body). The researchers are now looking at how different types of social interactions influence the number and health of neurons that survive a heart attack.
Mervis, R.F., Bachstetter, A., Neigh, G.N., Glasper, E.R., Kofler, J., Traystman, R.J. & DeVries, A.C. 2004. Cardiac arrest with cardiopulmonary resuscitation reduces dendritic spine density in CA1 pyramidal cells and selectively alters acquisition of spatial memory. European Journal of Neuroscience, 20 (7), 1865 – 1872.
http://www.eurekalert.org/pub_releases/2004-09/osu-cam092904.php
Inflammation associated with higher risk of age-related cognitive impairment
So-called “metabolic syndrome” is characterized most obviously by wide girth about the middle (being “apple-shaped”), as well as by high blood pressure and unhealthy levels of cholesterol, triglycerides and glucose in the blood. The syndrome is a well-known risk factor for cardiovascular disease. A new study finds the syndrome is also associated with a greater risk of cognitive impairment (hardly surprising, since many studies now indicate that cardiovascular risk factors are also risk factors for age-related cognitive impairment). The study tracked 2600 people, average age 74 years, over five years. Some 26% of those with the syndrome showed significant cognitive decline, compared to 21% of those without the syndrome. However, it appears the problem is not the syndrome so much as the high levels of inflammation that can result. About 30% of those with the syndrome plus high levels of inflammatory markers in their bloodstream showed significant cognitive decline. Those with the syndrome but no inflammation showed no increased risk.
Yaffe, K., Kanaya, A., Lindquist, K., Simonsick, E.M., Harris, T., Shorr, R.I., Tylavsky, F.A. & Newman, A.B. 2004. The Metabolic Syndrome, Inflammation, and Risk of Cognitive Decline. JAMA, 292, 2237-2242.
Age-related changes in the brain's white matter affect cognitive function
From around age 60, "white-matter lesions" appear in the brain, significantly affecting cognitive function. But without cognitive data from childhood, it is hard to know how much of the difference in cognitive abilities between elderly individuals is due to aging. A longitudinal study has been made possible by the Scottish Mental Survey of 1932, which gave 11-year-olds a validated cognitive test. Scottish researchers have tracked down healthy living men and women who took part in this Survey and retested 83 participants. Testing took place in 1999, when most participants were 78 years old.
It was found that the amount of white-matter lesions made a significant contribution to general cognitive ability differences in old age, independent of prior ability. The amount of white-matter lesions contributed 14.4% of the variance in cognitive scores; early IQ scores contributed 13.7%. The two factors were independent.
Although white-matter lesions are viewed as a normal part of aging, they are linked with other health problems, in particular to circulatory problems (including hypertension, diabetes, heart disease and cardiovascular risk factors).
Deary, I.J., Leaper, S.A., Murray, A.D., Staff, R.T. & Whalley, L.J. 2003. Cerebral White Matter Abnormalities and Lifetime Cognitive Change: A 67-Year Follow-Up of the Scottish Mental Survey of 1932. Psychology and Aging, 18 (1), 140-8.
http://www.eurekalert.org/pub_releases/2003-03/apa-aci031703.php