The brain finds a way to adapt, even when we remove half

A fascinating new study involving people who underwent hemispherectomy — surgery to remove one of the brain’s hemispheres — in childhood shows that these individuals now display almost no immediately obvious effects of this procedure.

illustration of brain sectionShare on Pinterest
Emerging evidence emphasizes the brain’s impressive ability to adapt, even when doctors remove half.

Brains have two halves, known as hemispheres. Each has various regions that regulate different aspects of our physical and cognitive functioning.

These halves do not work separately. Instead, they communicate by establishing complex neural networks that allow different parts of the body and mind to synchronize and work in harmony.

But what happens if you take one hemisphere away? That is the situation faced by people who undergo hemispherectomy — usually in childhood — as a means of treating severe seizures.

It would be easy to assume that removing half of someone’s brain would cause them to function in a visibly different way.

Yet, according to a recent case study featured in Cell Reports, this is not really the case. In fact, the brain learns to compensate for the loss.

‘Marveling’ at the brain’s adaptive ability

In the study, the investigators worked with six participants who had undergone hemispherectomy during childhood as a treatment for epileptic seizures.

The participants were in their 20s and early 30s at the start of the study, and they had undergone the brain surgeries when they were anywhere from 3 months to 11 years old.

The researchers say that working with participants who had undergone hemispherectomy at such different points in their childhoods helped them better understand how the brain adapts to this loss at different stages.

“It can help us examine how brain organization is possible in very different cases of hemispherectomy patients, which will allow us to better understand general brain mechanisms,” explains the study’s first author, Dorit Kliemann, Ph.D., from the California Institute of Technology, in Pasadena.

The team asked the participants who had undergone hemispherectomy — as well as six control participants — to receive functional MRI scans. The scans allowed the researchers to track activity in the brain while it was at rest.

By comparing the brain scans, the team found that the group who had undergone hemispherectomy had stronger brain network connectivity — rather than weaker connectivity, as one might expect — compared with the control group. The regions that the researchers focused on were those that regulate vision, movement, emotion, and cognition.

To confirm these findings, the team also compared the scans with data previously collected by the Brain Genomics Superstruct Project, which has amassed brain data from more than 1,500 participants.

“The people with hemispherectomies that we studied were remarkably high functioning,” emphasizes Kliemann.

“They have intact language skills — when I put them in the scanner, we made small talk, just like the hundreds of other individuals I have scanned,” she continues, noting that “You can almost forget their condition when you meet them for the first time.”

When I sit in front of the computer and see these MRI images showing only half a brain, I still marvel that the images are coming from the same human being whom I just saw talking and walking and who has chosen to devote his or her time to research.”

Dorit Kliemann, Ph.D.

In the future, the investigators plan to conduct another study to try and replicate the current findings, then to go even further by building an image of how the brain organizes and reorganizes itself to deal with injury.

Because, as Kliemann points out, while it is “remarkable” that people can live with half a brain, a very small brain lesion, a tumor, or a traumatic brain injury, caused by a biking accident, for example, can have “devastating effects.”

“We’re trying to understand the principles of brain reorganization that can lead to compensation. Maybe down the line, that work can inform targeted intervention strategies and different outcome scenarios, to help more people with brain injuries,” says Kliemann.

Source link

Short sleep may harm bone health in older women

Can insufficient sleep be harmful to bone health? New research in postmenopausal women has found that those who slept for no longer than 5 hours per night were most likely to have lower bone mineral density (BMD) and osteoporosis.

senior woman sleepingShare on Pinterest
New research finds a link between sleep loss and bone density.

A team from the University at Buffalo, NY, led the study of 11,084 postmenopausal women, all of whom were participants in the Women’s Health Initiative.

A recent paper in the Journal of Bone and Mineral Research gives a full account of the findings.

The investigation follows an earlier one in which the team had linked short sleep to a higher likelihood of bone fracture in women.

“Our study suggests that sleep may negatively impact bone health, adding to the list of the negative health impacts of poor sleep,” says lead study author Heather M. Ochs-Balcom, Ph.D., an associate professor of epidemiology and environmental health at the University at Buffalo School of Public Health and Health Professions.

“I hope,” she adds, “that it can also serve as a reminder to strive for the recommended 7 or more hours of sleep per night for our physical and mental health.”

Bone remodeling and osteoporosis

Bone is living tissue that undergoes continuous formation and resorption. The process, known as bone remodeling, removes old bone tissue and replaces it with new bone tissue.

“If you are sleeping less, one possible explanation is that bone remodeling isn’t happening properly,” Ochs-Balcom explains.

The term osteoporosis means porous bone and refers to a condition that develops when the quality and density of bone are greatly reduced. Osteoporosis is more common in older adults, with older women having the highest risk of developing it.

In most people, bone strength and density peak when they are in their late 20s. After that, as they continue to age, the rate of bone resorption gradually overtakes that of formation. The bone density of women reduces more rapidly during the first few years after menopause.

Worldwide, around 1 in 3 women and 1 in 5 men in their 50s and older are at risk of experiencing bone fracture due to osteoporosis, according to the International Osteoporosis Foundation.

The most common sites of fracture in people with osteoporosis are the hips, wrists, and spine.

Spinal fractures can be serious, resulting in severe back pain, structural irregularities, and loss of height. Hip fractures are also of concern, as they often require surgery and can lead to loss of independence. They also carry a raised risk of death.

Lower BMD measures tied to short sleep

In the new study, the team found that compared with women who slept more, those who reported getting only up to 5 hours of sleep per night had significantly lower values in four measures of BMD.

The four BMD measures were of the whole body, the hip, the neck, and the spine.

The researchers note that the lower BMD measures among the short sleep group were equivalent to being 1 year older.

The results were independent of other factors that could potentially influence them, such as age, race, the effects of menopause, smoking status, alcohol use, body mass index (BMI), use of sleeping pills, exercise, and type of bone density scanner.

The researchers emphasize that there is a positive message in these findings: Sleep, as with diet and exercise, is often something that people can work to change.

It’s really important to eat health[fully], and physical activity is important for bone health. That’s the exciting part of this story — most of us have control over when we turn off the lights, when we put the phone down.”

Heather M. Ochs-Balcom, Ph.D.

Source link

Study finds no link between statin use and memory harm in older adults

There is no link between statin use and memory impairment, researchers have concluded, after evaluating effects of the cholesterol-lowering drugs over 6 years in more than 1,000 older people in Australia.

doctor prescribing medicine to patientShare on Pinterest
New research reinforces the idea that statins are safe for older adults to use.

A team from the Garvan Institute of Medical Research and the University of New South Wales (UNSW), both in Sydney, Australia, led the study.

“Over 6 years, there was no difference in the rate of decline in memory or global cognition between statin users and never users,” they write in a recent Journal of the American College of Cardiology paper on the findings.

In fact, for certain individuals, statins may even offer some protection against memory decline, they suggest.

The results show that, among participants with risk factors for dementia, those who used statins had a slower rate of decline in memory and thinking skills than those who did not use the drugs.

The researchers hope that the findings will help to allay fears among consumers who have become concerned following reports of isolated cases of statin users experiencing cognitive decline.

“Many factors can contribute to the cognitive symptoms that isolated case reports describe,” says first study author Katherine Samaras, who is a professor at the Garvan Institute and head of its Clinical Obesity, Nutrition, and Adipose Biology Lab.

Results are ‘reassuring’

Dr. Perminder Sachdev, a professor of neuropsychiatry at UNSW and co-director of its Centre for Healthy Brain Ageing, is the study’s senior author.

He says, “In this study, our data reassuringly suggests that the use of statins to lower cholesterol levels is not likely to adversely affect memory function.”

Dr. Sachdev cautions, however, that because the study was observational and not a clinical trial, the findings are not conclusive.

“However,” he adds, “the evidence is mounting that statins are safe in relation to brain health, and this concern should not preclude their use in individuals who are likely to benefit from lower cholesterol levels.”

Statins are among the more widely prescribed drugs. Since the 1990s, doctors have been prescribing them for people with heart disease or high cholesterol in order to reduce the risk of cardiovascular events such as heart attack and stroke.

Prof. Samaras says that up to half of people do not fill their statin prescription, mainly because they are concerned about reports of individuals experiencing cognitive decline from statin use.

“We carried out the most comprehensive analysis of cognition in elderly statin users to date, and found no results to support that cholesterol-lowering statins cause memory impairment,” she notes.

No link to faster decline in memory, cognition

For the new study, the team used data from the prospective, observational Sydney Memory and Ageing Study.

The study participants were 1,037 people living in Sydney. Data collection began in 2005, when they were free of dementia and between 70 and 90 years old.

Over 6 years, the participants took 13 different tests to assess five areas of memory and cognition. They also underwent MRI scans to assess changes to their brains.

After adjusting the results to control for potential influencers, such as sex, age, and weight, the researchers found no difference in the rate of change in memory and other features of cognition between those who used statins and those who did not.

“There was also no difference in the change in brain volumes between the two groups,” observes Prof. Samaras, who is also an endocrinologist at St Vincent’s Hospital, in Sydney.

In addition, she and colleagues saw a slowing of cognitive decline among statin users with heart disease, diabetes, or other risk factors for dementia, compared with participants who had never used this type of drug.

“Our findings,” she adds, “demonstrate how crucial a healthy metabolism is to brain function and how therapies can modulate this to promote healthy aging.”

What we’ve come away with from this study is a reassurance for consumers to feel more confident about their statin prescription.”

Prof. Katherine Samaras

Source link

What is the state of the antibiotic resistance crisis?

While medical research has helped us overcome many health threats, we now face a new type of crisis: Many dangerous bacteria are becoming resistant to the drugs meant to fight them. Where do we go from here?

mrsa in petri dishShare on Pinterest
What is the state of the antibiotic resistance crisis? In this special feature, we investigate.

Healthcare professionals frequently use antibiotics to treat many forms of bacterial infection — from those that are mild to those that are potentially life threatening.

These bacteria-fighting drugs first became widely used in the early 20th century, though some medical historians argue that natural antibiotics featured in traditional therapies as early as 350–550.

For the most part, antibiotics have proved to be a crucial ally in the fight for health, but over the past few years, these drugs have begun to lose their footing in their confrontation with bacteria.

This is because more and more bacterial strains are developing antibiotic resistance — they are no longer affected by the drugs that once suppressed their growth and activity.

This means that many bacteria have become more threatening because we have fewer means of offsetting them.

When a doctor finds that a bacterial infection is not responding to traditional antibiotic treatment, they are forced to use stronger, more aggressive antibiotics or antibiotic combinations — an increasingly restrictive approach that can also bring about unwanted effects on health.

So how did we get here, and are things quite as bad as they seem? More importantly, what can doctors, researchers, and the public do to address the ever-growing issue of antibiotic resistance?

A growing health crisis

Only last week, the Centers for Disease Control and Prevention (CDC) released a report reviewing the newest data on antibiotic resistance.

From the very first page, they make it clear that we are facing an important threat — the CDC dedicate this report to “the 48,700 families who lose a loved one each year to antibiotic resistance or Clostridioides difficile, and the countless healthcare providers, public health experts, innovators, and others who are fighting back with everything they have.”

The situation is dire indeed: According to the newest data, more than 2.8 million people in the United States experience an infection from antibiotic resistant bacteria each year. Moreover, these “superbugs” cause 35,000 deaths per year in the country.

This threat is by no means new. It has persisted over the years, as Dr. Jesse Jacob — a specialist in bacteria resistant to multiple drugs, from the Emory Antibiotic Resistance Center at the Emory University School of Medicine, in Atlanta, GA — has told Medical News Today.

“[The] CDC released the first antibiotic resistance threat report in 2013, so this [situation] is not new,” Dr. Jacob told us.

Although, he added, “Since the first report, the number of deaths due to these infections has declined […] CDC has updated the estimated number of infections with antibiotic resistance per year from 2 million to nearly 3 million.”

The fact that so many bacteria are not responding to first- or even second-line treatments means that people with these infections face much higher risks and poorer health outcomes.

Antibiotic resistance has long been a problem, but the threats we face are real, immediate, and demand immediate action. Antibiotic resistance threatens modern medicine — our ability to safely perform routine surgeries and complicated organ transplants, as well as chemotherapy, all rely on the ability to prevent and treat infections.”

Dr. Jesse Jacob

Consistent antibiotic overuse

“Antibiotic resistance is not only a U.S. problem — it is a global crisis,” the recent CDC report states. But what has led to this problem reaching a crisis point?

The answer to that question is complex, according to a review featured in the journal Pharmacy and Therapeutics. The first and perhaps most obvious cause of antibiotic resistance is the misuse and overuse of these drugs.

Some people mistakenly believe that taking any kind of antibiotics acts as a sort of panacea, and they use these drugs to treat illnesses such as influenza. However, antibiotics can only target and kill bacteria and thus only treat bacterial infections.

Antibiotics are powerless against influenza and other illnesses caused by viruses. So when someone takes antibiotics for the wrong illness or uses too many too often, this kills off helpful bacteria that populate the body, threatening the delicate balance upon which health depends.

Moreover, bacteria are naturally prone to evolve and mutate, and some bacterial strains have, over time, found ways to adapt so that certain antibiotics will not affect them.

When we take antibiotics at the wrong time or if we overuse them, this allows resistant bacteria to take over more easily — to spread and multiply, sometimes giving rise to further strains of antibiotic resistant bacteria.

In the U.S. and other countries around the world, pharmacies are not permitted to sell antibiotics to people who are unable to produce a prescription. Nevertheless, studies suggest that many people are still able to purchase these drugs without official recommendations from their doctors.

Additionally, some research has shown that doctors sometimes mistakenly prescribe antibiotics or prescribe the wrong type of antibiotic, which has likely contributed to the current health crisis.

According to one study paper, 30–60% of antibiotics that doctors prescribe to people in intensive care units are not necessary.

Animals also factor in

It is not only humans who use antibiotics. While in some cases administering these drugs to animals is fully justified, recent studies have pointed out a problem when it comes to adding antibiotics to the food of farm animals destined for human consumption.

According to one recent study, “Of all antibiotics sold in the [U.S.], approximately 80% are sold for use in animal agriculture.”

Farmers have resorted to such high rates of antibiotic use in animals to boost growth rates and prevent infections, which are more common among livestock due to ways that producers handle these animals for breeding or as a source of meat.

New research covered on MNT has found that antibiotic resistance is now on the rise in farm animals, too — and the rates are increasing fast.

This situation, some investigators believe, also contributes to the global antibiotic resistance crisis that affects humans.

We need to better understand how antibiotic use in both humans and animals is related to growing antibiotic resistance — the concept is One Health, where the health of humans, animals, and plants [is] all linked and interdependent.”

Dr. Jesse Jacob

What are the ways forward?

In the face of this growing threat, policymakers have been pushing for a more careful use of antibiotics in general, while researchers have been searching for treatments that could effectively fight antibiotic resistant bacteria.

“More and more studies suggest ‘shorter is better,’ in terms of how long to treat common infections, but we need more evidence for many of the more complicated infections,” Dr. Jacob told us.

“We need research to find new drugs but can’t rely on a pipeline of new drugs alone to solve this problem, since resistance eventually happens to all drugs.”

Dr. Jacob also pointed to the need for better ways of determining which infections require antibiotics and when it is safe to start and stop this type of treatment.

“We also need to better understand nonantibiotic approaches to treat infections, including bacteriophages, vaccines, and antibodies,” he added.

The team at Emory University has been working hard to find a way to use existing antibiotics more effectively in order to fight off superbugs. The research — to which Dr. Jacob contributed — has shown that it may be possible to fight certain drug resistant bacteria using specific antibiotic combinations.

Another recent study, from the University of California, Los Angeles, suggests that instead of using combinations of one or two antibiotics, as doctors typically do, healthcare professionals may want to use combinations of four or even five such drugs.

Study co-author Pamela Yeh, Ph.D., argues that combinations of multiple antibiotics “will work much better” than current strategies, when it comes to fighting superbugs.

New drugs vs. a more natural approach

Other researchers are on the lookout for new drugs, following a World Health Organization (WHO) report from 2017 that signaled a “serious lack of new antibiotics.”

For example, a team of researchers from the University of Sheffield and the Rutherford Appleton Laboratory, in Didcot — both in the United Kingdom — started developing a new compound earlier this year that they hope will be able to effectively target bacteria, particularly strains of Escherichia coli, that are resistant to multiple drugs.

Other investigators are thinking further outside the box, working to harness the potential of bacteriophages, or bacteria-eating viruses. This is the case of a team from the University of Pittsburgh, in Pennsylvania, and the Howard Hughes Medical Institute, in Chevy Chase, MD.

These researchers report that they were able to successfully treat a severe liver infection in a 15-year-old using bacteriophages that ate the specific bacteria that had been causing serious harm.

Some researchers have turned their attention to probiotics, fighting bacteria with other bacteria.

Last year, specialists from the National Institute of Allergy and Infectious Diseases used Bacillus, a type of probiotic bacteria, to fight one of the most dangerous bacterial strains on the block: methicillin resistant Staphylococcus aureus, better known as MRSA. So far, their experiments in mouse models have yielded promising results.

And various scientists are looking for natural means of fighting superbugs. They suspect that compounds from plant-based sources could be just as, if not more, effective as antibiotics.

So far, researchers have cited green tea, cranberries, Persian shallots, and turmeric as potential sources of effective alternatives to antibiotics.

What we can do for now

For the time being, however, many specialists advise that the focus be on preventing infections from occurring. This, however, is more easily said than done.

The new report from the CDC lists antibiotic resistant Acinetobacter, Candida auris, C. difficile, and Enterobacteriaceae as some of the most urgent threats to health, according to recent data. The catch? All of these bacteria infect people who have recently received medical attention and who, usually, are still in the hospital.

“Some of these bacteria are carried by patients into the hospital, while others are acquired, in part due to otherwise lifesaving interventions, including antibiotic treatments and [other interventions involving] medical devices like intravenous catheters and mechanical ventilators,” Dr. Jacob explained to MNT.

What, then, should doctors do? According to Dr. Jacob, “Healthcare professionals can prevent infections by cleaning their hands and following infection prevention practices, using antibiotics appropriately (only when needed, for the minimum effective duration), vaccinating patients, and communicating between facilities to ensure awareness.”

“Educating patients and families about these approaches is key,” he added.

Regardless of how much care doctors take, however, dangerous bacteria may still prevail. A study from 2018 showed that many bacteria are becoming resistant to the alcohol-based disinfectants used in healthcare facilities.

And newer research, worryingly, has found that C. difficile appears to be resilient in the face of all hospital disinfectants.

Still, while we are faced with a serious threat, specialists maintain that prevention is possible — as long as individuals also do what they can to safeguard their own health. And the best way to do this is by listening to our physicians.

“Use antibiotics only when needed, especially not in ‘just in case’ scenarios,” emphasized Dr. Jacob.

“Discuss the need for antibiotics with your provider. Clean your hands. Get appropriate vaccinations, which save lives and can prevent antibiotic resistant infections,” he advised our readers.

Source link

Exercise after the age of 60 may prevent heart disease, stroke

A study finds that increased activity over the age of 60 can significantly reduce the risk of cardiovascular disease.

seniors doing physical activity Share on Pinterest
New research examines the impact of physical activity in people over the age of 60.

In 2015, 900 million people, globally, were over the age of 60. By 2050, the World Health Organization (WHO) expect that number to reach 2 billion.

While it is common for people to become less active as age takes a toll on one’s physical capabilities, a study just published in the European Heart Journalfinds that either maintaining levels of activity or becoming more active at this stage of life is important for reducing the risks of heart attack and stroke.

The researchers found that study participants who reduced their levels of exercise over time had a 27% greater likelihood of developing heart and blood vessel issues. Those who became more active reduced their risk by as much as 11%.

Studying physical activity in older age

The authors of the study — led by Kyuwoong Kim, of the Department of Biomedical Sciences, at Seoul National University, in South Korea — analyzed data from 1,119,925 men and women 60 years or older.

The data had been collected by the National Health Insurance Service (NIHS), which provides healthcare to about 97% of South Korea’s population. The average age of participants was 67, and 47% were men.

The NIHS conducted two health checks of the individuals, one in 2009–2010 and one in 2011–2012. The researchers collected data about these participants until 2016.

During each check, the healthcare providers asked the participants about their levels of physical activity and their lifestyles.

The researchers defined moderate physical activity as 30 minutes or more per day of dancing, gardening, or brisk walking. Twenty minutes or more of running, fast cycling, or aerobic exercise daily counted as vigorous exercise.

In their second NIHS health check, the participants reported how their levels of activity had changed since the first checkup.

A majority of the participants, about two-thirds, were inactive at the times of both checks. About 78% of women were physically inactive at the first health check, and this figure at the second check was roughly the same, at 77%.

Men were less inactive both times: 67% at the first screening and 66% at the second.

Just 22% of the overall group had increased their levels of activity between checks, while 54% of participants who had been exercising regularly five or more times per week had become inactive by the time of the second screening.

The researchers also analyzed national heart disease- and stroke-related medical claims and hospital records from January 2013 to December 2016.

By the end of the study period, 114,856 cases of heart disease or stroke had been reported among the cohort. The researchers adjusted for factors such as socioeconomic status, age, gender, other medical conditions, and lifestyle details such as smoking and alcohol use.

The impact of activity over the age of 60

The study’s analysis revealed that people who had increased their levels of activity from continuously inactive to moderately or vigorously active three to four times a week had lowered their risk of heart attack and stroke by 11%.

Those who had been active one or two times per week at the first check then increased to five or more times per week by the second check had lowered their risk by 10%.

People with disabilities also benefited from increasing their activity levels, reducing their risk of cardiovascular events by 16%. Participants with chronic conditions such as hypertension or diabetes saw a 4–7% reduction in their chances of experiencing a heart problem or stroke.

Meanwhile, the risk of cardiovascular problems had increased by 27% among participants who had reduced their levels of exercise between screenings.

The most important message from this research is that older adults should increase or maintain their exercise frequency to prevent cardiovascular disease.”

Kyuwoong Kim

“While older adults find it difficult to engage in regular physical activity as they age, our research suggests that it is necessary to be more physically active for cardiovascular health, and this is also true for people with disabilities and chronic health conditions,” he continues.

There are some limitations to this study. First, it considered only older adults in South Korea, and the applicability of the findings to older populations in other areas cannot be assumed.

Second, it strongly relies on self-reporting of activity levels, and the findings depend on the accuracy of each individual’s responses.

Finally, the NIHS questions did not encompass all forms of activity — for instance, the researchers did not include housework and other muscle-strengthening activities.

What to do with this information

Nonetheless, the study’s conclusions present compelling evidence that exercise remains important as we age.

The findings make the case that physical activity should become a significant, daily priority for older adults as our bodies grow in fragility, and discomfort becomes more common.

Our health services could be doing more to encourage this idea, suggests Kim, adding, “We believe that community-based programs to encourage physical activity among older adults should be promoted by governments.”

Also, from a clinical perspective, physicians should ‘prescribe’ physical activity along with other recommended medical treatments for people with a high risk of cardiovascular disease.”

Kyuwoong Kim

Source link