How the heart changes our sensory perception

A new study helps explain why our sensitivity to external sensory stimuli fluctuates with the beating of our hearts.

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New research finds a connection between external stimuli and a person’s heart rate.

According to popular culture, the brain and heart work in opposition to each other. The brain is the seat of rational, objective thought, while the heart is emotional and intuitive.

In reality, the activity of the two organs is intimately connected, with neither having a monopoly on reason or emotion.

Our hearts beat faster when we think about something exciting or frightening, for example. Conversely, an early morning jog can brighten our mood as our heart and lungs work harder.

A new study adds to evidence that the brain’s sensitivity to external sensory stimuli changes in step with the beating of the heart.

Researchers at the Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, and the Berlin School of Mind and Brain, both in Germany, set out to investigate this relationship.

Their study features in the journal Proceedings of the National Academy of Sciences of the United States of America.

Mild electric shocks

The scientists recruited 37 volunteers and carried out a total of 960 trials. In 800 of these, they gave the participant a mild electric shock to either the middle or index finger of their left hand. The volunteers indicated when they detected the stimulus, and in which finger they felt it.

The researchers told the participants that every trial contained a stimulus, but in the remaining 160 trials, there was no such stimulus.

During each trial, the researchers used electroencephalography (EEG) to record electrical activity in the brain and electrocardiography (EKG) to record the electrical activity of the heart.

They discovered two mechanisms that they believe underpin how the heart influences sensory perception.

The first shows how the phase of the heartbeat might change conscious experience.

Previous research by the same scientists found that during systole, when the heart pumps blood around the body, people are less able to detect and localize a weak electric shock than they are during diastole, when the heart is refilling with blood.

The new study linked this change in sensitivity to a distinctive feature of the brain’s electrical activity known as the P300, which relates to consciousness.

It seems that the P300 signals the extent to which a sensory stimulus is “surprising.” The signal is larger when the stimulus is unexpected, making it more worthy of conscious attention.

The researchers found that the P300 signal dipped during systole. They believe that this may be because the pulse of raised blood pressure that sweeps through the body when the heart contracts is a predictable stimulus that does not merit conscious attention.

It is also important that people do not confuse internal, self-generated stimuli, such as the heartbeat, with external stimuli.

However, the weakened P300 in the brain during systole seems to have the knock-on effect of reducing our sensitivity to sensory stimuli that coincide with it.

External or internal focus

The second, related mechanism that connects the heart and sensory perception appears to depend on whether the focus of our attention is inward or outward.

Another distinctive feature of the brain’s electrical activity, known as the heartbeat-evoked potential (HEP), reflects how consciously aware of our heartbeat we are at that moment.

The researchers discovered that when the volunteers’ HEP was strong, they were worse at detecting and localizing the electric shocks.

“This seems to be a result of directing our attention between external environmental signals and internal bodily signals,” explains Esra Al, who led the research.

The brain can rapidly switch conscious attention between internal sensations, such as breathing or heartbeat, and external sensations. It seems that we cannot focus on both simultaneously, though.

Beyond its curiosity value, the new research may also have implications for healthcare.

After a heart attack or stroke, the usual two way communication between heart and brain may become impaired.

“The new results might help to explain why patients after stroke often suffer from cardiac problems and why patients with cardiac disease often have impaired cognitive function,” says senior author Arno Villringer.

Source: MedicalNews Today

CDC releases consolidated COVID-19 testing recommendations

The Centers for Disease Control and Prevention (CDC) has released consolidated recommendations for COVID-19 testing, including interim testing guidelines for nursing home residents and healthcare personnel, as well as testing strategy options for high-density critical infrastructure workplaces after a COVID-19 case is identified. These recommendations compile and update previous testing guidance.

The consolidated recommendations for testing, Overview of Testing for SARS-CoV-2, were developed based on what is currently known about COVID-19 and are subject to change as additional information becomes available. This document includes a summary of current CDC recommendations for testing people who

• have signs or symptoms of COVID-19;
• have no symptoms but recently had contact with someone known or suspected to have COVID-19;
• have no symptoms and no known contact with someone known or suspected to have COVID-19 but still may be tested for early identification in special settings;
• have had confirmed COVID-19 but no longer have symptoms; and
• may be tested by public health officials to track spread of the virus that causes COVID-19.

Testing Guidelines for Nursing Homes is an important addition to other infection prevention and control (IPC) recommendations aimed at keeping COVID-19 out of nursing homes (as well as other long-term care facilities), detecting cases quickly if they do occur, and stopping further transmission in these facilities. Nursing home residents are at high risk for infection, serious illness, and death from the disease. Updated recommendations include recommendation against testing the same individual more than once in a 24-hour period; consideration for testing residents with symptoms for other causes of respiratory illness, such as influenza; and coordination of repeat testing in response to outbreaks with local, territorial, and state health departments.

Outbreaks of illness among workers in food-producing facilities and surrounding communities have raised unique questions about testing for COVID-19. Critical infrastructure employers have an obligation to manage the continuation of work in a way that best protects the health of their workers and the general public. Appropriate workplace protections, such as engineering and administrative controls, for those present in the workplace should remain in place. In addition, CDC’s Testing Strategy for Coronavirus (COVID-19) in High-Density Critical Infrastructure Workplaces after a COVID-19 Case is Identified presents different testing strategy options for exposed co-workers when public health organizations and employers determine testing is needed to help support existing disease control measures. Such strategies can aid in identifying infectious individuals with the goal of reducing transmission of SARS-CoV-2 in the workplace.

Source : https://www.cdc.gov

Sedentary? Feel happier with sleep or light activity instead

A study finds that going to bed or doing light tasks around the house helps your mood more than staying on the couch.

There is plenty of evidence that a sedentary lifestyle is less conducive to good health than a physically active one.

Meanwhile, SARS-CoV-2 and lockdowns have made it more difficult for many people to stay active or take up exercise.

Some of the current situation has to do with many of us working at home. Some of it, however, is optional, such as the hours we willingly allocate to TV binge-watching.

A new study suggests better and perhaps surprising ways to spend our spare time — that might benefit our health, as well.

The research appears now in the American Journal of Preventive Medicine.

Moving from the couch to the bed, and to sleep, is more refreshing than spending hours sitting in front of a screen — and the same is true of doing light housework, the study suggests.

The findings arrive at a useful time for those struggling to feel good during the COVID-19 pandemic and lockdowns.

Lead author Jacob Meyer of Ohio State University (OSU) in Columbus, Ohio, says, “With everything happening right now, this is one thing we can control or manage, and it has the potential to help our mental health.”

Escaping the couch

According to the study’s authors, previous research has shown that adults in the United States typically spend 75% of their waking hours being sedentary, including 90% of their leisure time.

Even active adults have seen their activity levels drop by 32% in lockdown, according to preliminary data the researchers released in May.

During quarantine, and after a day’s work, we may find ourselves in search of restorative activity within our four walls, and immersion in online entertainment may seem a reasonable form of escape.

The new OSU study proposes, however, that there are better options that people can easily work into their quarantine schedules.

“It may be easier for people to change their behavior if they feel it’s doable and doesn’t require a major change,” according to Meyer.

The first of the study’s conclusions is that people might do themselves a favor to turn off the TV and simply go to bed for the night.

The researchers correlated getting more sleep with feeling less stressed, being in a better mood, and even having a lower body mass index (BMI).

They also associate a lasting reduction in BMI, as well as improved mood, with some light activity performed around the home.

While previous studies — and this one — document the value of moderate-to-high levels of activity, Meyer and his colleagues see real benefits even from less demanding activities, such as walking around as people talk on their phones, or standing as they prepare dinner.

“People may not even think about some of these activities as physical activity,” Meyer says.

However, they do more for you than merely being sedentary, the researcher maintains.

“Light activity is much lower intensity than going to the gym or walking to work,” he argues, “but taking these steps to break up long periods of sitting may have an impact.”

The study

The OSU study analyzed data from the 2010–2015 Energy Balance Study at the University of South Carolina. It used 423 participants ranging from 21 to 35 years of age, with BMI values of 20–35. Each individual received $500 for taking part in the study.

To accurately track participants’ activity levels, the researchers gave each a SenseWear armband, which is an activity tracking device, to avoid inaccuracies that could result from self-reporting.

Each participant was monitored for 10 consecutive days for 24 hours a day, except during water-based activities, such as bathing or swimming.

Individuals logged any periods in which they were not wearing their armbands, as well as their activities at those times. A follow-up exam a year after the study revealed the lasting benefits of replacing time spent sedentary with light exercise.

Participants’ moods were self-reported using the Profile of Mood States. Cohen’s 10-item Perceived Stress Scale measured their perception of stress. Three height and weight measurements, on average, were taken for each individual to determine their BMI.

Source MedicalNews Today

COVID-19: Cancer drug may quench inflammation in severely ill patients

An international clinical trial has been launched after a cancer drug that targets the root cause of extreme inflammation showed promise in a preliminary study.

In some people with mild or moderate COVID-19, the illness caused by the SARS-CoV-2 virus, their condition briefly improves, only to suddenly worsen.

These people may then develop severe breathing difficulties, known as acute respiratory distress syndrome.

Scientists speculate that even when the infection is being brought under control, the virus can trigger an excessive immune response, causing hyper-inflammation of the lungs and other organs.

This type of inflammatory response is thought to begin when receptors in immune cells called macrophages recognize the genetic material of viruses such as SARS-CoV-2. They respond by initiating a massive release of immune-signalling molecules called cytokines.

This “cytokine storm” appears to cause the hyper-inflammation that damages the lungs and other organs of critically ill patients. Currently, no proven treatment can prevent or reverse the damage.

In macrophages, an enzyme called Bruton tyrosine kinase (BTK) is responsible for initiating the cytokine storm.

A drug that inhibits the activity of BTK — called acalabrutinib — is already in use as a treatment for certain blood cancers.

Damping down inflammation

Researchers at the National Cancer Institute, in the United States, realized that because acalabrutinib inhibits BTK, it could potentially reduce inflammation in people with severe COVID-19.

To test the safety and efficacy of the drug in this context, they collaborated with scientists at the National Institute of Allergy and Infectious Diseases, the Walter Reed National Military Medical Center, and four other hospitals in the country.

The researchers have published the results of their trial in the journal Science Immunology.

For between 10 and 14 days, the team administered the drug to 19 people hospitalized for COVID-19. At the start of the study, 11 participants were breathing with the help of oxygen masks, and eight were on ventilators.

By the end of the follow-up period, eight of the 11 patients who had been receiving supplemental oxygen no longer needed help breathing and had been discharged from the hospital.

Of the eight patients on ventilators at the start of the treatment, four had been taken off the machines, or “extubated,” and two had been discharged. Two of the patients had died. 

The drug, however, appeared to cause no toxic side effects.

The researchers also monitored two markers of inflammation in the blood — levels of a cytokine called interleukin 6 (IL-6) and C-reactive protein (CRP).

Of the 11 patients on supplemental oxygen at the start of the study, CRP levels returned to normal in 10 and were decreasing in one. Of the five patients who also had their IL-6 levels measured, the levels of three had returned to normal, and the levels of two had fallen sharply.

The picture was more mixed among the patients on ventilators. Reductions were smaller overall, and in some of these patients, the levels fluctuated.

Source: MedicalNews Today

Best available evidence supports physical distancing and wearing face masks

A new study provides the best available evidence for key ways of reducing SARS-CoV-2 transmission.

A new meta-analysis, which brings together a significant amount of research on SARS-CoV-2 and related coronavirus protection, provides the best available evidence for physical distancing, mask use, and eye protection.

Until randomized controlled trials are conducted and can offer a greater degree of certainty, this study, which appears in The Lancet, provides doctors and policymakers with interim information on which to base key decisions.

Protective measures

The sudden, rapid emergence and spread of SARS-CoV-2 has left researchers searching for a safe, effective vaccine to reduce the transmission. However, the development of a vaccine may be 12–18 months away, if indeed such a vaccine can ever be found.

In the absence of a vaccine or other treatments that would slow the spread of the virus, public health organizations have recommended a series of social and behavioral changes to reduce the transmission.

In addition to frequent handwashing, authorities have emphasized the importance of physical distancing: leaving the house less frequently and maintaining as much distance as possible from others at all times while outside.

They also recommend the use of face masks and eye protection, particularly among healthcare workers and people working in the community.

However, experts are still debating when and how these policies should be implemented — including what constitutes the minimum distance that people should maintain from one another, when and where to wear personal protective equipment, and how effective this equipment is against the virus.

Significant meta-analysis

To address this, the World Health Organization (WHO) commissioned the present meta-analysis, which was conducted by an international team of researchers, clinicians, patients, and policy experts.

The authors sifted through over 20,000 research papers to find 44 comparative studies that related to the protective benefits of physical distancing, wearing face masks, and wearing eye protection.

The included studies addressed infection with the SARS-CoV-2 virus, the SARS virus, which caused an outbreak in the early 2000s, or the MERS-CoV virus, which caused an outbreak in the early 2010s. Because SARS-CoV and MERS-CoV are similar to SARS-CoV-2, research into these pathogens can provide insight.

The authors found no differences in the effectiveness of distancing, face masks, and eye protection in responses to the three coronaviruses and, therefore, feel confident in pooling the findings from the various studies.

Distancing and masks reduce transmission

The authors conclude that there is good evidence that maintaining a minimum distance of 1 meter, or about 3.3 feet, from other people is likely to have a significant effect on reducing the spread of the virus.

Across 38 studies that included information about distancing, infection rates overall were reduced to 2.6% when maintaining a distance of more than 1 meter from a person with the infection. By comparison, among studies in which distancing was less than 1 meter, the infection rate was 12.8%.

Furthermore, the authors found evidence that increasing the distance to 2 meters was likely to have an even greater effect.

Dr. Derek Chu, a lead author of the study, said: “We found that with each additional 1 meter of distance, the relative degree of protection increased about two-fold. […] Overall, [this] supports measures of at least 2 meters when feasible and possible.”

The authors point out that their finding of increased risk of infection at 2 meters has implications for the cut-off for contact tracing, and they suggest that 2 meters should be adopted universally.

The authors note that there is a consensus that the virus is transmitted through water droplets expelled from a person’s throat or nose when they cough or sneeze. These droplets are unable to stay airborne for very long, which is likely to explain why distances of at least 1 meter significantly reduce transmission.

Evidence of whether the virus can also transmit as an aerosol — surviving on very small particles that are also expelled as a person coughs and sneezes — has been mixed. These particles may be able to stay airborne for longer and thus infect a person at a greater distance.

As well as maintaining a minimum distance, face and eye masks are also designed to stop the spread of the virus, either by reducing the amount that a person expels or reducing the amount that can access a person’s mouth or eyes and, therefore, their respiratory system.

The authors found good evidence that both face masks and eye masks significantly reduced transmission of the virus for health care workers and people working in the community, such as care home workers.

The odds of developing an infection with a coronavirus were reduced by 78% when wearing any mask, compared with the odds of infection when not wearing a mask. When using masks that conform to the N95 standard, this figure increased to 96%.

According to co-lead study author Dr. Holger Schünemann, who, like Dr. Chu, works at McMaster University, in Ontario, Canada, “Although the direct evidence is limited, the use of masks in the community provides protection, and possibly N95 or similar respirators worn by healthcare workers suggest greater protection than other face masks.”

In a Lancet podcast, Dr. Schünemann confirmed that even wearing a “self-made face mask is better than having no face mask.”

While the study presents the best available evidence for policymakers to draw on when making key decisions about how to respond to the pandemic, particularly as lockdown measures begin to ease, the authors acknowledged their analysis has some limits.

None of the currently available studies looking at the protection afforded by physical distancing, face masks, and eye protection were randomized, and many of the studies did not specify exact distances.

Around three-quarters of the studies focused on healthcare settings, which means that while the evidence to support wearing face masks in these contexts is good, there is more uncertainty surrounding the use in nonhealthcare settings.

However, the authors state that once they had taken account of low levels of use of the highly effective N95 respirator masks in the community, they found other types of masks to be equally effective in both hospital and community settings.

Nonetheless, in the absence of randomized controlled trials that can provide more information and a greater degree of certainty — and until a vaccine or effective treatment is developed — the research presents policymakers and clinicians with valuable interim information on which to base key decisions.

MedicalNews Today

Older men less worried about COVID-19, study suggests

A study has found that older men may worry less about COVID-19 and may be less likely to make behavioral changes in response to the pandemic.

New research has found that despite being a more at-risk demographic, older men are likely to worry less and make fewer behavioral changes in response to the SARS-CoV-2 pandemic.

The research, published in The Journals of Gerontology, concludes that older men might require more education and intervention to ensure that they perceive the risks of COVID-19 accurately.

Worrying about COVID-19

The sudden emergence and rapid spread of the SARS-CoV-2 virus, as well as the risks associated with contracting COVID-19, have necessitated radical changes in people’s everyday life.

Emerging information about the virus has identified the demographics most vulnerable to a severe reaction to the virus.

While everyone should be making behavioral changes to reduce the spread of the virus, vulnerable groups need to take extra care, since severe COVID-19 can be life threatening.

According to the Centers for Disease Control and Prevention (CDC), 8 out of 10 COVID deaths in the United States have been people aged 65 and over. Research has also shown that men are at higher risk of a worse disease outcome, including death.

Given this, one may expect that men aged 65 and over may be more cautious and more worried about the virus. However, previous research has shown that older men are less likely to worry about death and their mortality than other demographics.

According to Dr. Sarah Barber, a gerontology and psychology researcher at Georgia State University and corresponding author of the study, “[n]ot only do older adults exhibit less negative emotions in their daily lives, they also exhibit less worry and fewer PTSD symptoms following natural disasters and terrorist attacks.

“In normal circumstances, not worrying as much is a good thing. Everyday life is probably happier if we worry less. However, where COVID-19 is concerned, we expected that lower amounts of worry would translate into fewer protective COVID-19 behavior changes.”

The present paper explored whether these known reductions in worry were the same or similar concerning COVID-19 and if this was likely to affect a person’s likelihood of making behavioral changes in response to the virus.

Risk, worry, and behavioral changes

To conduct the research, the authors gathered participants aged 18–35 and 65–81. After excluding participants who had received a diagnosis of COVID-19, the remaining sample consisted of 146 younger people (78 women, 68 men) and 156 older people (74 women, 82 men).

The researchers asked each participant to fill in a questionnaire to assess their relative levels of risk perception, worry, and behavior changes in response to the pandemic.

The researchers assessed the risk by asking if the participants thought people were over-reacting to the virus and if they thought the virus was no worse than seasonal flu. The participants answered the questions according to a scale of 1 (strongly disagree) to 7 (strongly agree).

To assess worry, the participants answered a series of questions about whether they worried about catching COVID-19 or its negative effects on their livelihood. The questionnaire asked the participants to select one of the following options to indicate their levels of worry: (a) not at all, (b) a little, (c) a moderate amount, (d) a lot, and (e) a great deal.

The questionnaire also posed a series of questions to assess behavioral changes. Questions included whether the participants were washing their hands more frequently, if they were wearing a hygiene mask more often, or if they had stopped shaking hands. For each question, participants could respond either (a) Yes, (b) I am considering it, but not yet doing it, and (c) No.

Less worry and fewer changes

The study found that most people were moderately concerned about the pandemic, and 80% of respondents had made behavioral changes in response to it.

However, the study also found that older men worried less than other participants about COVID-19 and made the fewest changes to their behavior.

Despite these findings, Dr. Barber does not believe the answer is to encourage older men to worry more. As she and co-author Hyunji Kim note, “[w]orry has been associated with increased risk for cardiovascular disease, with poorer physical health, and with greater declines in learning and memory over time.”

Dr. Barber thinks it would be better to ensure older men accurately understand the risks of COVID 19.

“Our study showed that for older men, accurate perception of risk worked as well as worry to predict preventive behaviors,” Dr. Barber said.

An accurate perception of risk may have improved since the researchers conducted the study. Dr. Barber notes that the study took place “right after the pandemic was declared, and we all hope that a more accurate perception of risk has evolved over the last 2 months.”

Nonetheless, the study’s findings indicate the importance of ensuring people, particularly older men, have an accurate perception of the risks of COVID-19.

Source: MedicalNews Today

COVID-19 patients experience neurological symptoms

Altered mental status and stroke are the most common neurological symptoms that hospitalized COVID-19 patients experience, according to a new study from Italy.

People with SARS-CoV-2, which is the virus that causes COVID-19, can experience a variety of symptoms.

According to the Centers for Disease Control and Prevention (CDC), these are usually physical symptoms, such as fever or chills, a cough, fatigue, and shortness of breath.

Among the warning signs that indicate that a person needs emergency medical care, the CDC list confusion and an inability to wake up or stay awake.

Although the neurological symptoms associated with COVID-19 have received much less attention than the physical symptoms, some studies suggest that they are common among people with severe forms of the illness.

A study in the BMJ, for example, found that among COVID-19 patients who died at a hospital in Wuhan, China, 22% had experienced a disorder of consciousness, compared with only 1% of those who recovered.

A preprint of another study of hospitalized patients in China found that overall, 25% had central nervous system symptoms or diseases. These included headaches, dizziness, impaired consciousness, uncoordinated muscle movements, seizures, and strokes.

These were more likely in those with severe disease. For example, 6% in the severe group had strokes, compared with 1% in the non-severe group.

In the first published study of its kind, researchers at the University of Cincinnati in Ohio and several Italian universities analyzed the findings of imaging investigations into hospitalized patients in Italy who experienced neurological symptoms with COVID-19.

The researchers have now published their results in the journal Radiology.

Second epicenter

After China, Italy became the second epicenter of the COVID-19 pandemic. Italy has now had more than 33,000 deaths.

The researchers analyzed the records of patients treated at the University of Brescia, the University of Eastern Piedmont in Novara, and the University of Sassari.

Out of 725 patients, 15% experienced neurological symptoms or disease. Of this 15%, 99% underwent a CT scan.

The most common neurological symptoms were “altered mental state,” which 59% of the patients experienced, and ischemic strokes, which 31% of the patients experienced.

“Altered mental status” encompasses a wide range of possible signs and symptoms, including confusion, delirium, and coma.

Among the less common neurological symptoms were headache (12%), seizures (9%), and dizziness (4%).

Imaging revealed acute abnormalities in 47% of the patients. Among the most common findings were ischemic strokes, and in 6% of the patients, there were signs of intracranial hemorrhage.

Early interventions

“These newly discovered patterns could help doctors better and sooner recognize associations with COVID-19 and possibly provide earlier interventions,” says lead study author Dr. Abdelkader Mahammedi, an assistant professor of radiology at the University of Cincinnati.

The study was unable to shed light on whether or not SARS-CoV-2 directly damages the central nervous system. It might be that neurological symptoms are a side effect of critical illness. Lack of oxygen in the brain, for example, can cause confusion or loss of consciousness.

In addition, of the 108 patients, 71% had one or more preexisting chronic conditions. These included hypertension, diabetes, coronary artery disease, and cerebrovascular disease.

In their paper, the researchers cite accumulating evidence to suggest that some people with severe COVID-19 experience a “cytokine storm,” in which the body produces an excess of pro-inflammatory molecules called cytokines. This can cause blood clots, which can, in turn, trigger ischemic strokes.

“This topic definitely needs more research,” says Dr. Mahammedi.

“Currently,” he adds, “we have a poor understanding of the neurological symptoms in COVID-19 patients, whether these are arising from critical illness or from direct central nervous system invasion of SARS-CoV-2. We hope further study on this subject will help in uncovering clues and providing better interventions for patients.”

Source: MedicalNews Today