By Janice Wood Associate News Editor
People who develop atrial fibrillation — a type of irregular heartbeat common in old age — may also be more likely to develop problems with memory and thinking, according to a new study.
“Problems with memory and thinking are common for people as they get older. Our study shows that, on average, problems with memory and thinking may start earlier or get worse more quickly in people who have atrial fibrillation,” said study author Evan L. Thacker, Ph.D., of the University of Alabama at Birmingham.
“This means that heart health is an important factor related to brain health.”
The study analyzed results from more than 5,100 people age 65 and older from four communities in the United States who were enrolled in the Cardiovascular Health Study.
Participants did not have a history of atrial fibrillation or stroke at the start of the study. They were followed for an average of seven years, taking a 100-point memory and thinking test every year.
Of the 5,150 participants, 552, or about 11 percent, developed atrial fibrillation during the study.
The researchers found that people with atrial fibrillation were more likely to experience lower memory and thinking scores at earlier ages than people with no history of atrial fibrillation.
For example, from age 80 to age 85 the average score on the 100-point test went down by about 6 points for people without atrial fibrillation. But the average dropped by about 10 points for people with atrial fibrillation, the researchers noted.
For participants ages 75 and older, the average rate of decline was about three to four points faster per five years of aging with atrial fibrillation compared to those without the condition, he added.
“This suggests that, on average, people with atrial fibrillation may be more likely to develop cognitive impairment or dementia at earlier ages than people with no history of atrial fibrillation,” he said.
Thacker noted that scores below 78 was suggestive of dementia. People without atrial fibrillation in the study were predicted to score below 78 points at age 87, while people with atrial fibrillation were predicted to score below 78 points at age 85, two years earlier.
“If there is indeed a link between atrial fibrillation and memory and thinking decline, the next steps are to learn why that decline happens and how we can prevent that decline,” said Thacker.
The study was published in the online issue of Neurology.
Source: American Academy of Neurology
Author: Torkel Klingberg, MD, PhD, Professor of Cognitive Neuroscience at the Karolinska Institute
Working memory deficits occur in many conditions
There is a normal variability from individual to individual in working memory capacity. In the individual, capacity can also be temporarily decreased due to stress or lack of sleep. Moreover, there is a normal decline in capacity with aging, starting around 25-30 years of age, with a decline of about 5-10% per decade.
Except for this normal variability, working memory capacity is also affected in a range of clinical conditions, affecting the neural systems underlying working memory. Studies on both animals and humans have shown that the prefrontal and parietal cortexes are essential for working memory performance; as is the basal ganglia, as well as correct dopaminergic transmission. When these systems are affected, working memory is impaired.
Stroke affecting the frontal lobe is associated with working memory deficits, as are traumatic brain injuries (Robertson and Murre, 1999). In these cases, the working memory deficits lead to attention and planning problems. Attention Deficit Hyperactivity Disorder (ADHD and ADD) is associated with disturbances of both the frontal lobe and the dopaminergic system, and is consequently also associated with working memory deficits. Learning disability is another prevalent condition, in children and in adults, which can be defined as academic difficulties that are not due to inadequate opportunity to learn, general intelligence, nor to physical/emotional disorders, but to basic disorders in specific psychological processes. It has been shown that learning disability can be directly linked to deficits in working memory (Gathercole and Pickering, 2000).
ADHD is a widespread and serious disorder with a key WM component
ADHD is a disorder which includes severe problems of attention, impulsivity and hyperactivity. ADHD affects 3-5% of children between 6-16 years, which makes it the most common neuropsychiatric disorder. When children with ADHD grow older, the hyperactivity decreases, but problems of inattention, which often lead to academic and occupational failure, remain in the majority of cases. ADHD has a strong genetic component, with heritability estimated around 70%. Deficits in working memory are thought to be of central importance in explaining many cognitive and behavioral problems in ADHD (Barkley, 1997; Castellanos and Tannock, 2002; Rapport et al. , 2000; Westerberg et al., 2004). Westerberg et al. (2004) com¬pared working memory tasks with other tasks and showed that children had most problems with working memory tasks. A meta-analysis of 46 studies (Martinussen et al., 2005) confirmed the WM deficits in ADHD, and also showed that the deficits are most pronounced in the visuo-spatial domain.
Can working memory be improved?
Torkel Klingberg, MD PhD, has conducted research at Karolinska Institutet for several years concerning the neural basis of working memory and working memory deficits in children. Working memory capacity has generally been held to be a fixed property of the individual.However, Klingberg, Helena Westerberg, Ph.D., and others at the Department for Neuropediatrics at Astrid Lind¬gren’s Children’s Hospital (part of Karolinska University Hospital), started to develop methods for improving working memory in 1999. These methods are influenced by animal research on mechanisms for training induced plasticity (Buonomano and Merzenich, 1998). Development was conducted in collaboration with Jonas Beckeman and David Skoglund, professional game developers who helped solve technical issues and helped make the training more rewarding.
The training consists of a specific set of working memory tasks that are performed on a computer, where the difficulty level is adjusted according to a specific algorithm. The users complete a fixed number of trials every day, taking about 30-40 minutes daily. This is done for five days a week over five weeks. During training, performance results are saved and can be used for later analysis.
The program is called Cogmed RM, and has been developed by Cogmed Systems AB.
Author: Torkel Klingberg, MD, PhD, Professor of Cognitive Neuroscience at the Karolinska Institute
Working memory is the ability to keep information online for a brief period of time, which is essential for many cognitive tasks such as control of attention and problem solving. In contrast to what was previously assumed, we have shown that systematic training can improve working memory capacity, in both children and adults. Brain imaging studies also show that working memory training leads to increased brain activity in the prefrontal and parietal cortex. Improving working memory capacity leads to better performance on several tasks that require working memory and control of attention and it translates to increased attentiveness in everyday life.
Working Memory is a key function necessary for critical cognitive tasks
Working memory is the ability to keep and manipulate information online for a brief period of time. This ability can be measured for example by testing how many digits a subject can repeat back after hearing them once (verbal working memory) or how many positions a subject can remember after seeing them once (visual working memory).
In daily life we use working memory to remember plans or instructions of what to do next. But keeping information online is a very basic function that has proved to be of central importance in a wide range of cognitive tasks. Verbal working memory is necessary for comprehending long sentences; and verbal working memory capacity predicts performance on reading comprehension in the scholastic aptitude test (SAT) (Daneman and Carpenter, 1980). Working memory is also important for control of attention, and to maintain task-relevant information during problem solving. More generally, working memory has been suggested to be the single most important factor in determining general intellectual ability (SüB et al., 2002). About 50% of differences between individuals in non-verbal IQ can be explained by differences in working memory capacity (Conway et al., 2003).
More recently, it has also become clear that there is a strong link between working memory capacity and the ability to resist distractions and irrelevant information. One study used the so called “cocktail party effect”, i.e. our ability to focus on one voice despite noisy surroundings, and showed that this ability is related to working memory capacity (Conway et al., 2001). Recent studies have also shown that low working memory is related to being “off-task” and daydreaming (Kane et al., 2007). These psychological studies are consistent with neuroimaging studies, which have shown that subjects with higher working memory capacity are less likely to store irrelevant information (Vogel et al., 2005). The prefrontal cortex is important in providing this “filtering” of irrelevant information, and subjects with higher working memory capacity have a higher prefrontal activity and are better at filtering out distractors (McNab and Klingberg, 2008).
When people have deficits in working memory, they are often experienced as “inattention problems”, e.g. to have problems focusing on reading a text; or “memory problems”, e.g. forgetting what to do in the few seconds of walking from one room to the another, or being easily distracted while trying to focus on a task. In children the problem is often remembering what to do next, which makes them unable to finish an activity according to plan.
In conclusion, working memory allows us to hold on to information in order to complete a task, and is especially important in any cognitively demanding environment with irrelevant distractions.
THURSDAY, Feb. 28, 2013 By John Gever, Senior Editor, MedPage Today(MedPage Today) — Institutionalized dementia patients who received a tailored educational program on good eating habits were less likely to show symptoms of depression 6 months later, results of a Taiwanese study indicated.
Mean scores on the Chinese version of the Cornell Scale for Depression in Dementia declined 0.73 points among patients assigned to a individualized program, whereas a control group receiving usual care showed an average increase of 0.79 points, according to Li-Chan Lin, PhD, RN, of National Yang-Ming University in Taipei, Taiwan, and Hua-Shan Wu, PhD, RN, of Shan Medical University in Taichung, Taiwan.
A third study arm, in which patients received a non-individualized version of the educational program, showed no change in depression scores, the researchers reported online in the Journal of Advanced Nursing.
Nutritional status and body mass index likewise increased with the individualized program, decreased in the control group, and showed little change with the non-individualized program, Lin and Wu indicated.
“The improvement in nutritional status may have led to reduced fatigue and increased vitality,” they wrote. “Once the participants perceived the improvements in their health, pessimism, the sense of multiple illnesses, hopelessness, or even worthlessness seldom emerged.”
Multiple aspects of proper nutrition are often compromised in dementia. As Lin and Wu explained, “identifying foods, transferring foods, chewing, and swallowing” become progressively difficult for patients with cognitive deficits. Moreover, several previous studies have linked poor nutritional status to depression, in otherwise healthy adults as well as in those with dementia.
In the current study, Lin and Wu tested an approach combining a technique called “spaced retrieval” with Montessori-type methods aimed at helping dementia patients eat more and eat more regularly.
Spaced retrieval is a teaching method to help people with information recall. It involves challenging the person to remember something for increasing time intervals. If it is successfully recalled after 2 minutes, a second challenge will require recall after 4 minutes. When recall fails, the challenge is done again at the last successful interval.
Lin and Wu chose Montessori-based activities to reinforce healthy eating behaviors because cognitive abilities in dementia patients in some ways resemble those of young children.
The combination of the two techniques “activate the effects of repetition priming and procedural memory in the nondeclarative memory,” the researchers explained, leading to development of desired habits.
They randomized 90 patients to usual care or two versions of the program. Both versions were built around sessions lasting 35-40 minutes three times a week. The training focused on eight basic eating behaviors, from remembering mealtimes to swallowing after chewing.
In the individualized program, training was progressively intensified for individual patients if they demonstrated mastery at a given level. The number of sessions also depended on individual patients’ needs, such that participants with mild dementia could receive up to 23 sessions whereas the maximum in moderate or severe dementia was 35.
For patients assigned to the non-individualized program, training intensity was stepped up only when more than half the participants had shown mastery. The number of sessions was fixed at 24 over an 8-week period.
Patients were recruited from veterans’ homes in Taiwan. About 40 percent had scores on the Chinese version of the Mini-Mental State Examination of 6 t0 11 (severe dementia), and another 40 percent had scores of 12 to 17 (moderate dementia).
From 4 percent to 18 percent of each study arm were taking antidepressants, 32 percent to 45 percent were taking antipsychotic medications, and 20 percent to 29 percent were on anti-anxiety drugs.
Mean BMI at baseline ranged from 20.3 to 22.9 in the three arms. Scores on the Chinese version of the Mini-Nutritional Assessment averaged 19.2 to 21.5. On the Cornell depression scale, mean baseline scores were 0.26 to 1.55.
Over the 6-month post-training evaluation period, changes in Cornell and nutritional scores were strongly correlated in the individualized intervention group, with an R2 value of 0.44. Changes in nutritional scores also correlated strongly and significantly in this group with nutritional scores at baseline.
“The greatest improvement of nutritional status and depressive symptoms resulting from the individualized intervention occurred between the immediate post-training period and the 1-month follow-up,” Lin and Wu noted.
They suggested that, therefore, additional “booster sessions” may be helpful in maintaining or increasing the short-term gains.
Limitations to the study included its restriction to residents of veterans’ homes and the small number of outcome measures.
Source: Eating Helps Dementia Patients Avoid Depression
ScienceDaily (Oct. 4, 2012) — Can you bite into an apple? If so, you are more likely to maintain mental abilities, according to new research from Karolinska Institutet in Sweden.
Health & Medicine
Mind & Brain
•Dementia with Lewy bodies
The population is aging, and the older we become the more likely it is that we risk deterioration of our cognitive functions, such as memory, decision-making and problem solving. Research indicates several possible contributors to these changes, with several studies demonstrating an association between not having teeth and loss of cognitive function and a higher risk of dementia.
One reason for this could be that few or no teeth makes chewing difficult, which leads to a reduction in the blood flow to the brain. However, to date there has been no direct investigation into the significance of chewing ability in a national representative sample of elderly people.
Now a team comprised of researchers from the Department of Dental Medicine and the Aging Research Center (ARC) at Karolinska Institutet and from Karlstad University in Sweden have looked at tooth loss, chewing ability and cognitive function in a random nationwide sample of 557 people aged 77 or older. They found that those who had difficulty chewing hard food such as apples had a significantly higher risk of developing cognitive impairments. This correlation remained even when controlling for sex, age, education and mental health problems, variables that are often reported to impact on cognition. Whether chewing ability was sustained with natural teeth or dentures also had no bearing on the effect.
written by Kyle. J. Norton
About 5-8% of all people over the age of 65 have some form of dementia, and this number doubles every five years above that age. Dementia is the loss of mental ability that is severe enough to interfere with people’s every life and Alzheimer’s disease is the most common type of dementia in aging people. American typical diet contains high amount of saturated and trans fat, artificial ingredients with less fruits and vegetable which can lead to dementia and other kind of diseases
I. Causes of Dementia
H. Life Style causes of Dementia
1. Unhealthy diet
Unhealthy lifestyle choices lead to an increasing incidence of obesity, dyslipidemia and hypertension–components of the metabolic syndrome. These disorders can also be linked to AD. Recent research supports the hypothesis that calorie intake, among other non-genetic factors, can influence the risk of clinical dementia.(1)
2. Psychological and Neurological effects
Researchers at the G.J. Patel Ayurved College, showed that Mind and body are inseparable entities and influences each other until death. Many factors such as stress, anxiety, depression, negative thoughts, unhealthy life style, unwholesome diet etc., disturb mental and physical wellbeing. Senile dementia is the mental deterioration, i.e, loss of intellectual ability associated with old age. It causes progressive deterioration of mental faculties, e.g., memory, intellect, attention, thinking, comprehension and personality, with preservation of normal level of consciousness.(2)
3. Excessive alcohol drinking
Moderate alcohol drinking of less than 2 cups for men and 1 cups for women are said to offers possible health benefits(3), but Binge drinking in midlife is associated with an increased risk of dementia, according to the follow-up, 103 participants had developed dementia. Binge drinking (ie, alcohol exceeding the amount of 5 bottles of beer or a bottle of wine on 1 occasion at least monthly), as reported in 1975, was associated with a relative risk of 3.2 (95% confidence interval=1.2-8.6) for dementia. Passing out at least twice as a result of excessive alcohol use during the previous year, as reported in 1981, was associated with a relative risk of 10.5 (2.4-46) for dementia in drinkers.(4)
Smoking is a risk factor for several life-threatening diseases, but its long-term association with dementia is controversial and somewhat understudied.In a studyof a total of 5367 people (25.4%) were diagnosed as having dementia (including 1136 cases of AD and 416 cases of VaD) during a mean follow-up period of 23 years. Results were adjusted for age, sex, education, race, marital status, hypertension, hyperlipidemia, body mass index, diabetes, heart disease, stroke, and alcohol use, Dr. Rusanen M, and the team at the University of Eastern Finland, said ” heavy smoking in midlife was associated with a greater than 100% increase in risk of dementia, AD, and VaD more than 2 decades later. These results suggest that the brain is not immune to long-term consequences of heavy smoking”(5).
By Janice Wood The molecular structure of a protein involved in Alzheimer’s disease — and the surprising discovery that it binds cholesterol — could lead to new therapies for the disease, according to new research.
Charles Sanders, Ph.D., professor of biochemistry, and colleagues at Vanderbilt University recently determined the structure of part of the amyloid precursor protein (APP) — the source of amyloid-beta, which characterizes Alzheimer’s disease.
Amyloid-beta clumps together into oligomers that kill neurons, causing dementia and memory loss. The amyloid-beta oligomers eventually form plaques in the brain, one of the hallmarks of Alzheimer’s, the researchers note.
“Anything that lowers amyloid-beta production should help prevent, or possibly treat, Alzheimer’s disease,” Sanders said.
Amyloid-beta production requires two “cuts” of the APP protein, he said. The first cut, by the enzyme beta-secretase, generates the C99 protein, which is then cut by gamma-secretase to release amyloid-beta. The Vanderbilt researchers used nuclear magnetic resonance and electron paragmagnetic resonance spectroscopy to determine the structure of C99.
The researchers said they were surprised to discover what appeared to be a “binding” domain in the protein.
Based on previously reported evidence that cholesterol promotes Alzheimer’s disease, they suspected that cholesterol might be the binding partner.
The researchers used a model membrane system called “bicelles” that Sanders developed as a postdoctoral fellow to demonstrate that C99 binds cholesterol.
“It has long been thought that cholesterol somehow promotes Alzheimer’s disease, but the mechanisms haven’t been clear,” Sanders said. “Cholesterol binding to APP and its C99 fragment is probably one of the ways it makes the disease more likely.”
Sanders and his team propose that cholesterol binding moves APP to special regions of the cell membrane called “lipid rafts,” which contain “cliques of molecules that like to hang out together,” he said.
“We think that when APP doesn’t have cholesterol around, it doesn’t care what part of the membrane it’s in,” Sanders said. “But when it binds (to) cholesterol, that drives it to lipid rafts, where these ‘bad’ secretases are waiting to clip it and produce amyloid-beta.”
The findings suggest a new strategy to reduce amyloid-beta production, he said.
“If you could develop a drug that blocks cholesterol from binding to APP, then you would keep the protein from going to lipid rafts,” he said. “Instead it would be cleaved by alpha-secretase — a ‘good’ secretase that isn’t in rafts and doesn’t generate amyloid-beta.”
Drugs that inhibit beta- or gamma-secretase to limit amyloid-beta production have been developed and tested, but they have toxic side effects, the researchers note.
A drug that blocks cholesterol binding to APP may be more effective in reducing amyloid-beta levels and in preventing, or treating, Alzheimer’s disease, the researchers conclude.