After a Stroke, Diabetes Could Worsen Brain Function

Having Type 2 diabetes could cause cognitive impairment in stroke survivors, according to new research that points out the need to aggressively treat prediabetes.

A new analysis of seven international studies found that three to six months after a stroke, the participants with diabetes functioned worse than those without diabetes on measures for memory, attention, mental flexibility, processing speed, language and other examples of cognitive function.

“That’s why Type 2 diabetes is another important target in the prevention of dementia, and the focus should be on early treatment for prediabetes to delay or prevent the progression to Type 2 diabetes,” Dr. Perminder Sachdev said in a news release. She is the study’s senior author and scientia professor at UNSW Sydney’s Centre for Healthy Brain Ageing in Kensington, Australia.

Previous research by Sachdev and colleagues determined that stroke patients with a diabetes history had worse brain function than those without the condition. But this new work, published Thursday in the American Heart Association’s journal Stroke, looked at whether that held true for people with prediabetes.

“This is important because prediabetes is very common, and individuals can have prediabetes for several years before progressing to Type 2 diabetes,” Sachdev said. “Early and aggressive treatment of prediabetes can delay or prevent Type 2 diabetes. If we target the treatment of prediabetes, could this prevent the development of dementia in some individuals?”

The analysis included data from 1,601 stroke patients in Australia, France, Korea, the Netherlands, Singapore and the United States. Their average age was 66 and almost all had clot-caused strokes. Overall, 70% were Asian, 26% white and 2.6% African American.

Fasting blood sugar levels measured at hospital admission and medical history were used to define Type 2 diabetes and prediabetes. But the study was limited by not having information about the duration and severity of diabetes and having only one blood sugar measurement.

After adjusting for age, sex and education, researchers found “significantly poorer” function in stroke survivors with diabetes – but not in those with prediabetes. The findings held up even after researchers adjusted for additional factors such as ethnicity, high blood pressure, smoking, body mass index, abnormal heart rhythm and previous stroke.

“The deficits we found in all areas of cognitive function highlight the importance of assessing the capacity for self-care in patients with Type 2 diabetes following a stroke,” Jess Lo, lead author of the study, said in a news release. She is a research associate at UNSW Sydney’s Centre for Healthy Brain Ageing.

Health care providers should ensure stroke survivors have the mental competency to fulfill the complex tasks needed to manage diabetes, Lo said.

That “can include measuring glucose levels multiple times a day, managing glucose monitoring devices, adjusting medication doses, self-administering insulin or other medications, and understanding food labels and portion sizes to adjust what is eaten at each meal or snack.”

Source: American Heart Association


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Get Moving, Seniors: It’s Good For Your Brain

Want to give your brain a boost? Go for a swim, take a walk, or spin your partner on the living room floor.

A new study finds that aerobic exercise can improve older adults’ thinking and memory, even if they’re longtime couch potatoes.

This type of exercise increases blood flow to the brain and counters the effects of normal aging, according to the study published online May 13 in the journal Neurology.

“As we all find out eventually, we lose a bit mentally and physically as we age. But even if you start an exercise program later in life, the benefit to your brain may be immense,” said study author Marc Poulin, of the University of Calgary School of Medicine in Canada.

“Sure, aerobic exercise gets blood moving through your body. As our study found, it may also get blood moving to your brain, particularly in areas responsible for verbal fluency and executive functions. Our finding may be important, especially for older adults at risk for Alzheimer’s and other dementias and brain disease,” Poulin said in a journal news release.

The study included 206 adults, average age 66, with no history of memory or heart problems.

For six months, they took part in supervised exercise program three times a week. As they progressed, their workout increased from an average 20 minutes a day to least 40 minutes. They were also asked to work out on their own once a week.

At the end of the exercise program, participants had a 5.7% improvement on tests of executive function, which includes mental abilities used to focus, plan, recall instructions and multi-task. They also had 2.4% increase in verbal fluency, a measure of how quickly a person can retrieve information.

“This change in verbal fluency is what you’d expect to see in someone five years younger,” Poulin said.

On average, blood flow to their brain increased 2.8% — a gain tied to a number of improvements in types of thinking that typically decline with age.

“Our study showed that six months’ worth of vigorous exercise may pump blood to regions of the brain that specifically improve your verbal skills as well as memory and mental sharpness,” Poulin said.

“At a time when these results would be expected to be decreasing due to normal aging, to have these types of increases is exciting,” he said.

Source: HealthDay


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New Imaging Tool Helps Researchers See Extent of Alzheimer’s Early Damage

Bill Hathaway wrote . . . . . . . . .

New imaging technology allows scientists to see the widespread loss of brain synapses in early stages of Alzheimer’s disease, a finding that one day may help aid in drug development, according to a new Yale University study.

The research, published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, compared the density of synapses, which transmit signals between neighboring brain cells, in people with early stages of Alzheimer’s with those of people who have no evidence of the disease. As expected, the loss of synapses in those with an early stage of Alzheimer’s was particularly high in areas surrounding the hippocampus, an area of the brain crucial to formation of memory, the scientists report.

“However, our new methods enable us to detect widespread synaptic losses thoughout the brain,” said Yale’s Adam Mecca, assistant professor of psychiatry and first author of the paper. “This gives us confidence that we may use these results as a biomarker outcome for therapeutic trials, which could help speed development of new drugs to combat the disease.”

To get a clearer picture of the early effects of Alzheimer’s, the researchers used positron emission tomography (PET) imaging of a protein found in almost all brain synapses. Previous imaging technologies had been able to show in broad strokes the loss of brain tissue or reduced brain metabolism in Alzheimer’s. However, the new PET scans show the distribution of synaptic damage, a more specific disease pathology present at early stages of the disease, the authors say.

“These methods will allow us to examine synaptic loss at still earlier stages of disease — when people have evidence of Alzheimer’s pathogenesis but have not yet manifested symptoms,” said Christopher van Dyck, professor of psychiatry, neurology, and neuroscience, and senior author of the study.

Source: Yale University

How Exercise Supports Your Mental Fitness: Current Recommendations

Sporting activity can improve your cognitive performance. However, there are numerous different types of sports and a wide range of exercise and training. Which type and how much exercise will keep your mind in top shape? This is the question that has been explored by researchers at the University of Basel and their colleagues at the University of Tsukuba in Japan through a large-scale analysis of the scientific literature. They have used this analysis to derive recommendations that they recently published in the journal Nature Human Behaviour.

Coordinated sports are particularly effective

The research group with the participation of Dr. Sebastian Ludyga and Professor Uwe Pühse evaluated 80 individual studies to identify a few key characteristics. Endurance training, strength training or a mix of these components seem to improve cognitive performance. However, coordinated and challenging sports that require complex movement patterns and interaction with fellow players are significantly more effective. “To coordinate during a sport seems to be even more important than the total volume of sporting activity,” explains Ludyga.

A higher total extent of activity does not necessarily lead to a correspondingly higher level of effectiveness for mental fitness. Longer duration per exercise unit promises a greater improvement of cognitive performance only over a longer period of time.

All age groups benefit

Just like our physical condition, cognitive performance changes over the course of our lives. There is great for potential for improvement during childhood (cognitive development phase) and during old age (cognitive degradation phase). However, the research group of the Department of Sport, Exercise and Health (DSBG) at the University of Basel was unable to find an indicator of different levels of effectiveness of sporting activities within the varying age groups.

Furthermore, sporting activities from primary school age to later age do not have to be fundamentally different in order to improve cognitive performance. Different age groups can thus be combined for a common goal during sports. “This is already being implemented selectively with joint exercise programs for children and their grandparents,” says Pühse. Such programs could thus be further expanded.

Intense sports sessions for boys and men

The same volume of sports activity has a different effect on physical fitness for men and women, as we are already aware. However, the research group has now been able to verify this for mental fitness. Men accordingly benefit more from sporting activity.

Differences between the sexes are particularly evident in the intensity of movement, but not in the type of sport. A hard workout seems to be particularly worthwhile for boys and men. Paired with a gradual increase in intensity, this leads to a significantly greater improvement in cognitive performance over a longer period of time.

In contrast, the positive effect on women and girls disappears if the intensity is increased too quickly. The results of the research suggest that they should choose low to medium intensity sporting activities if they want to increase their cognitive fitness.

Source: University of Basel,

Being Right-brained or Left-brained Comes Down to Molecular Switches

Scientists may have solved one of the most puzzling and persistent mysteries in neuroscience: why some people are “right-brained” while others are “left-brained.”

The answer lies in how certain genes on each side of the brain are switched “on” and “off” through a process called epigenetic regulation. The findings may explain why Parkinson’s disease and other neurological disorders frequently affect one side of the body first, a revelation that has far-reaching implications for development of potential future treatments.

The study was led by Van Andel Institute’s Viviane Labrie, Ph.D., and published in the journal Genome Biology.

“The mechanisms underlying brain asymmetry have been an elephant in the room for decades,” Labrie said. “It’s thrilling to finally uncover its cause, particularly given its potential for helping us better understand and, hopefully one day, better treat diseases like Parkinson’s.”

Each cell in the brain has the same genes but it is epigenetics that dictate whether those genes are switched “on” or “off.” Labrie and her collaborators found numerous epigenetic differences between the hemispheres of healthy brains that are linked to variations in gene activity. Notably, these differences, or asymmetry, could make one side of the brain more vulnerable to neurological diseases.

For example, epigenetic abnormalities on one side of the brain could make that hemisphere more susceptible to the processes that cause the death of brain cells in Parkinson’s. The differences in cell death across hemispheres leads to the appearance of the disease’s hallmark symptoms, such as tremor, on one side of the body before the other. As the disease progresses, symptoms on the side first affected often are more severe than symptoms on the other side of the body.

The findings also give scientists a vital window into the various biological pathways that contribute to symptom asymmetry in Parkinson’s, including brain cell development, immune function and cellular communication.

“We all start out with prominent differences between the left and right sides of our brains. As we age, however, our hemispheres become more epigenetically similar. For Parkinson’s, this is significant: people whose hemispheres are more alike early in life experienced faster disease progression, while people whose hemispheres were more asymmetric had slower disease progression,” Labrie said. “Many of these changes are clustered around genes known to impact Parkinson’s risk. There is huge potential to translate these findings into new therapeutic strategies.”

Labrie is already starting to look at this phenomenon in other neurological diseases like Alzheimer’s.

The study is one of the first to parse the molecular causes of brain asymmetry. Early research on the left versus right brain was conducted in the mid-20th century by Roger Sperry, whose groundbreaking work with split-brain patients earned him a Nobel Prize.

Source: VAn Andel Institute


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