How sleep can affect your heart

This article describes the negative effects of getting a poor night's sleep, especially on your heart.

You might think that those nights when you don’t get a wink of sleep can’t do you any harm apart from the frustration you feel knowing that you have to work the next day and you might be asleep at the wheel.

However, sleep disorders have been associated with many conditions that you might develop later on in life. There are studies proving that insomnia or very few hours of sleep per night are linked to memory loss or to strokes as you become older.

Thus, it was proved that people who have the tendency to sleep less than seven hours every day are more likely to suffer a stroke.

A new research now shows that fewer hours of sleep every night might also be a cause for heart attacks later on in life.

The study conducted by researchers at World Health Organization revealed that sleeping disorders are as bad for your heart as smoking or leading a sedentary life.

“Sleep is not a trivial issue. Sleeping disorders were associated with greatly increased incidences of both heart attack and stroke. Poor sleep should be considered a modifiable risk factor for cardiovascular disease along with smoking, lack of exercise and poor diet,” said Professor Valery Gafarov.

He also added that a normal person should sleep between 7 and 8 hours every night and, if they don’t manage to do that, they should seek specialized help from a sleep doctor.

The study, which began in 1994, involved 657 men whose ages varied from 25 to 64 years old, from Russia. They had never suffered any heart attack or stroke and they did not have diabetes, which is a disease that can lead to these conditions.

Their sleep quality was rated according to the Jenkins Sleep Scale and it was regarded as either very bad, bad or poor for those who had a sleeping disorder.

They were monitored for heart attacks and strokes over the next 14 years and it was revealed that 63 percent of those who suffered a heart attack also suffered from a sleeping disorder.

Therefore, it was shown that people who had sleeping problems were more than 2 times more likely to have a heart attack and 1.5 to 4 times more at risk of having a stroke that those who had a  normal sleep every night.

These findings are extremely worrying, given the fact that the mortality rate associated with heart attacks is extremely high. It was estimated that it represents half of the causes of death all over the world, making it the leading cause in many countries, including the U.S.

This is why preventive measures are extremely important. We need to sleep well, exercise regularly, avoid smoking and drinking alcohol, eat healthy food and maintain a normal body weight.

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Study: Losing sleep can hurt your memory

A study shows that losing sleep can hurt a person's memory.

Lack of sleep, already considered a public health epidemic, can also lead to errors in memory, finds a new study by researchers at Michigan State University and the University of California, Irvine.

The study, published online in the journalPsychological Science, found participants deprived of a night's sleep were more likely to flub the details of a simulated burglary they were shown in a series of images.

Distorted memory can have serious consequences in areas such as criminal justice, where eyewitness misidentifications are thought to be the leading cause of wrongful convictions in the United States.

"We found memory distortion is greater after sleep deprivation," said Kimberly Fenn, MSU associate professor of psychology and co-investigator on the study. "And people are getting less sleep each night than they ever have."

The Centers for Disease Control and Prevention calls insufficient sleep an epidemic and said it's linked to vehicle crashes, industrial disasters and chronic diseases such as hypertension and diabetes.

The researchers conducted experiments at MSU and UC-Irvine to gauge the effect of insufficient sleep on memory. The results: Participants who were kept awake for 24 hours -- and even those who got five or fewer hours of sleep -- were more likely to mix up event details than participants who were well rested.

"People who repeatedly get low amounts of sleep every night could be more prone in the long run to develop these forms of memory distortion," Fenn said. "It's not just a full night of sleep deprivation that puts them at risk."

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Brain damage can occur even in mild brain injuries

A study shows that even a mild brain injury can cause lasting brain damage.

Even mild traumatic brain injury may cause brain damage and thinking and memory problems, according to a study published in the July 16, 2014, online issue of Neurology®, the medical journal of the American Academy of Neurology.

For the study, 44 people with a mild traumatic brain injury and nine people with a moderate traumatic brain injury were compared to 33 people with no brain injury. All of the participants took tests of their thinking and memory skills. At the same time, they had diffusion tensor imaging scans, a type of MRI scan that is more sensitive than traditional MRI for detecting damage to brain cells and helps map fiber tracts that connect brain regions. The people with brain injuries had their scans an average of six days after the injury. A year later, 23 of those with injuries had another scan and took the cognitive tests again.

Compared to the people with no brain injury, those with injuries had brain damage in brain white matter consisting of disruption to nerve axons, those parts of nerve cells that make up white matter and that allow brain cells to transmit messages to each other.

The study found that patient scores on the verbal letter fluency task, a test of thinking and memory skills, were 25 percent lower than in the healthy people. This was strongly related to the imaging measures of white matter damage.

“Most of the studies thus far have focused on people with severe and chronic traumatic brain injury,” said study author Andrew Blamire, PhD, of Newcastle University in the United Kingdom. “We studied patients who had suffered clinically mild injuries often from common accidents such as falling from a bicycle, or slow speed car accidents. This finding is especially important, as 90 percent of all traumatic brain injuries are mild to moderate.”

One year after the injury, the scores on thinking and memory tests were the same for people with brain injuries and those with no injuries, but there were still areas of brain damage in people with injuries. “These results show that thinking skills were recovering over time,” Blamire said. “The areas of brain damage were not as widespread across the brain as previously, but focused in certain areas of the brain, which could indicate that the brain was compensating for the injuries.”

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Too much and too little sleep indicate memory problems

This article claims that both too much and too little sleep can lead to memory problems in older women.

Seniors who slept too little or too much during midlife or after are at increased risk for memory problems, as are those whose sleep habits changed over time, a new study suggests.

Researchers looked at more than 15,000 women, 70 and older, who took part in a large study of health professionals. The women were depression- and stroke-free when they underwent their initial assessment.

Participants who slept five hours or less, or nine hours or more a day -- either in midlife or later life -- had worse memory than those who slept seven hours a day. The difference in memory was equivalent to nearly two extra years of age, the researchers said.

Women whose amount of sleep changed by more than two hours a night over time had poorer memory than those who had no sleep changes, according to the study published May 1 in the Journal of the American Geriatrics Society.

"Given the importance of preserving memory into later life, it is critical to identify modifiable factors, such as sleeping habits, that may help achieve this goal," study leader Elizabeth Devore, of Brigham and Women's Hospital in Boston, said in a hospital news release.

"Our findings suggest that getting an 'average' amount of sleep, seven hours per day, may help maintain memory in later life and that clinical interventions based on sleep therapy should be examined for the prevention of [mental] impairment," she added.

The study adds "to our knowledge about how sleep impacts memory. More research is needed to confirm these findings and explore possible mechanisms underlying these associations," Devore concluded.

While the study found an association between sleep time during midlife and older age and memory function in older women, it did not prove a cause-and-effect relationship.

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Sea lions have form of epilepsy similar to humans

Researchers find that some sea lions have a form of epilepsy that is similar to epilepsy seen in humans.

California sea lions exposed to a toxin in algae develop a form of epilepsy that is similar to one in humans, according to a new study led by Stanford University School of Medicine researchers.

Every year, hundreds of sea lions wash up along the California coast, suffering seizures caused by exposure to domoic acid, a neurotoxin that can produce memory loss, tremors, convulsions and death. Domoic acid is produced by algae blooms that have been proliferating along the coast in recent years, accumulating in anchovies and other small fish that the sea lions feed on, said Paul Buckmaster, PhD, DVM, professor of comparative medicine at Stanford.

Buckmaster and his colleagues studied the brains of affected sea lions and found they had a pattern of damage in the hippocampus -- the brain's memory center -- much like that in humans with temporal lobe epilepsy.

"We found there was a loss of neurons in specific patterns that closely matched what is found in people," he said. "And there is synaptic reorganization -- a rewiring of surviving neurons. This also matches what is found in humans with temporal lobe epilepsy."

He said further studies in the animals could help in developing better treatments for them, as well as for their human counterparts.

Buckmaster is lead author of the study, which will be published online March 19 in the Journal of Comparative Neurology.

Temporal lobe epilepsy is one of the most common forms of epilepsy in humans and has no cure. It typically begins with a seizure caused by an insult to the brain, such as head trauma, high fever or lack of oxygen. Months or years later, it progresses into epilepsy, with periodic seizures that may be treated with anti-convulsive medication or, in some cases, surgery.

There is one documented case of a patient who was found to have developed temporal lobe epilepsy following exposure to domoic acid. The 84-year-old Canadian was one of more 250 people who became ill in 1987 after eating mussels from Prince Edward Island that were found to be contaminated with domoic acid. The man, who suffered nausea, vomiting, coma and convulsions, initially recovered but was diagnosed a year later with temporal lobe epilepsy; he died some two years later of pneumonia. Three other Canadians died in the mussel incident as a result of domoic acid poisoning.

In sea lions, the first link between domoic acid and epilepsy was established in 1998, when some 400 animals washed ashore in California's Monterey Bay on Memorial Day weekend. Some had died, while others were in the throes of seizures, weaving their heads, flailing about and scratching themselves in an odd way. About 100 of the animals were rescued by the Marine Mammal Center in Sausalito, where experts were at a loss to explain the animals' bizarre behavior, said Frances Gulland, PhD, DVM, senior scientist at the center and co-author of the current study.

She contacted Christopher Scholin, PhD, now president of the Monterey Bay Aquarium Research Institute, who discovered the bay waters had the highest levels of domoic acid ever recorded, she said. Blood and urine samples from the sea lions confirmed they had domoic acid poisoning. The researchers documented their findings in a 2000 Nature paper.

Since then, Gulland said a few hundred sea lions with epilepsy have been rescued every year by the mammal center, and about half respond to treatment with anti-convulsive therapy. But some suffer from seizures that may continue for hours, causing extensive brain damage. These animals have no hope for recovery and have to be euthanized.

In these cases, mammal center officials turn to Buckmaster, a veterinarian who is an expert in epilepsy in animals. For the past four years, he has been working on studies of the epileptic sea lions, examining samples of their brain tissue to better understand what underlies the disease.

In the current study, he and his colleagues retrieved samples of tissue from the hippocampus, which they cut into thin slices and then stained so that the neurons could be viewed under a microscope. They collected tissues from 14 sea lions with epilepsy and compared them with similar samples from nine without epilepsy who had died of other causes, such as cancer, infection or shark bite wounds.

The animals with epilepsy had lost about 50 percent of the neurons in the hippocampus, similar to what is seen in people with temporal lobe epilepsy, Buckmaster said. The researchers observed another striking similarity: In most cases, the hippocampus on only one side of the brain in the sea lions showed any signs of damage.

"That was really surprising," Buckmaster said. "That is what you find in people -- 80 percent of the time the damage is just on one side."

In rats and mice, which are the models typically used in epilepsy studies, injury is seen in the hippocampus of both sides of the brain, he said.

The results are curious, as sea lions ingest the toxin throughout their bodies, he said. "Why would there be damage only on one side?"

He speculated that it could be related to the size and structure of the brain. Like the human brain, the sea lion brain is significantly larger than a rodent brain -- 700 times larger than a mouse brain and 180 times larger than a rat brain -- and contains many more neurons. However, the average number of synapses -- connections between nerve cells -- per neuron is roughly the same in rodents and humans. Without more synapses for each neuron, the probability of any two neurons in the large brain being connected must be lower than it is in the small brain, Buckmaster surmised. So this relative lack of interconnectivity in human and sea lion brains could be why damage remains localized to a specific area, he said. (The number of synapses hasn't been measured in sea lions, though it seems reasonable to speculate that they would have a similar ratio of synapses per neuron, he said.)

The researchers also noticed a pattern of rewiring in the brains of the epileptic sea lions that is similar to that in humans with temporal lobe epilepsy. Among the neurons that survived the assault by domoic acid, some of the axons -- the nerve fibers that carry electrical impulses away from the neuron -- extended into a region of the hippocampus where they don't normally grow. That creates a kind of positive feedback loop in which the cells are exciting themselves, which might contribute to more seizure activity, Buckmaster said.

"We see this in people with temporal lobe epilepsy," he said. "It's one of the key neuropathological features of the disease."

Because of these similarities, he said the sea lions could serve as good models for developing new treatments for the disease. Patients typically are treated with daily, anti-convulsive drugs, or in some cases with surgery in which doctors remove a portion of the hippocampus -- an invasive procedure that often causes some memory loss.

The ultimate goal, he said, is to develop a therapy that could be used early on to forestall brain damage and prevent further seizures.

"What we need is an interventional treatment -- both in humans and sea lions," he said. "You'd give the treatment right after the brain injury, and that would prevent them from developing epilepsy. That's the dream, but we are not there yet."

Gulland said the research has been a valuable contribution to the field. "For us, the work Dr. Buckmaster has done is really important because it shows the sea lions are really epileptic," she said. "We used to think if they had just a small amount of the poison, they could recover and be fine. But if the seizure has gone on for any length of time, they become permanently affected. It's very distressing to the animals and to the people who work with them to see them coming back having seizure after seizure."

Buckmaster is now planning new studies of the sea lions using the entire brain, fully preserved right after the animals' death so the "beautiful anatomy" of various structures is visible.

"We will be able to see areas of brain damage we have never seen before," he said. "Based on the hippocampus results, there's a good chance it will be similar to people."

He also has a grant to study the effects of in utero exposure to domoic acid. Some of the sea lions in the study were younger animals thought to be exposed before birth, as domoic acid can concentrate in amniotic fluid at a time when the nervous system is developing, Buckmaster said. The mammal center has treated three pups from mothers that were exposed to domoic acid in pregnancy, two of whom developed epilepsy later in life. It's believed that humans could be susceptible to in utero damage from the toxin as well, he said.

Meanwhile, the problem of marine mammal exposure to domoic acid is not likely to go away anytime soon. The harmful algae blooms, believed to be produced by micronutrients contained in agricultural runoff, have been increasing in frequency along the California coast and are lasting longer, sometimes for months at a time, Gulland said.

And while sea lions may be the most visible victims, it's believed that other marine mammals, such as whales and dolphins, are affected by the toxin and may have seizures and drown in the open ocean, though the extent of the problem isn't known, Gulland said. William van Bonn, DVM, formerly of the Marine Mammal Center and now at the Shedd Aquarium in Chicago, was senior author of the paper.

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Study: Concussions and Alzheimer's are linked

According to a new study, older adults with memory issues and Alzheimer's disease also generally have a history of concussion.

Older adults with memory problems and a history of concussion have more buildup of Alzheimer's disease-associated plaques in the brain than those who also had concussions but don't have memory problems, according to a new study.

''What we think it suggests is, head trauma is associated with Alzheimer's-type dementia -- it's a risk factor," said study researcher Michelle Mielke, an associate professor of epidemiology and neurology at Mayo Clinic Rochester. "But it doesn't mean someone with head trauma is [automatically] going to develop Alzheimer's."

Her study is published online Dec. 26 and in the Jan. 7 print issue of the journal Neurology.

Previous studies looking at whether head trauma is a risk factor for Alzheimer's have come up with conflicting results, she noted. And Mielke stressed that she has found only a link or association, not a cause-and-effect relationship.

In the study, Mielke and her team evaluated 448 residents of Olmsted County, Minn., who had no signs of memory problems. They also evaluated another 141 residents with memory and thinking problems known as mild cognitive impairment.

More than 5 million Americans have Alzheimer's disease, according to the Alzheimer's Association. Plaques are deposits of a protein fragment known as beta-amyloid that can build up in between the brain's nerve cells. While most people develop some with age, those who develop Alzheimer's generally get many more, according to the Alzheimer's Association. They also tend to get them in a predictable pattern, starting in brain areas crucial for memory.

In the Mayo study, all participants were aged 70 or older. The participants reported if they ever had a brain injury that involved loss of consciousness or memory.

Of the 448 without any memory problems, 17 percent had reported a brain injury. Of the 141 with memory problems, 18 percent did. This suggests that the link between head trauma and the plaques is complex, Mielke said, as the proportion of people reporting concussion was the same in both groups.

Brain scans were done on all the participants. Those who had both concussion history and cognitive [mental] impairment had levels of amyloid plaques that were 18 percent higher than those with cognitive impairment but no head trauma history, the investigators found.

Among those with mild cognitive impairment, those with concussion histories had a nearly five times higher risk of elevated plaque levels than those without a history of concussion.

The researchers don't know why some with concussion history develop memory problems and others do not.

The research was funded by the U.S. National Institutes of Health, among several other supporters.

The study adds valuable information for experts in the field, said Dr. Robert Glatter, director of sports medicine and traumatic brain injury in the department of emergency medicine at Lenox Hill Hospital, in New York City. Glatter, who is also a former sideline physician for the National Football League's New York Jets, reviewed the new study findings.

Other studies, he said, often rely on postmortem information. In the Mayo study, participants had to have loss of consciousness as a measure of having a concussion history, Glatter noted. However, he added, the new thinking is that loss of consciousness is not necessary to define a concussion -- one can occur without that.

The effect of head injury may be cumulative over time in the development of Alzheimer's, he said. In the past, experts thought only severe head trauma was linked with Alzheimer's, but less severe injury may actually be relevant as well, he added.

Some other factor or factors yet to be discovered may be at play, Glatter said.

Both Mielke and Glatter stressed that concussions don't automatically lead to Alzheimer's. "Not all people with head trauma develop Alzheimer's," Glatter said.

"If you do hit your head, it doesn't mean you are going to develop Alzheimer's," Mielke said, although "it may increase your risk."

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Study: Brain damage from concussion stays after symptoms subside

A study shows that after symptoms from a concussion go away, the brain damage from the concussion persists.

Months after concussion symptoms such as dizziness, headaches and memory loss fade, the brain continues to show signs of injury, a new study suggests.

Comparing 50 concussion patients with the same number of healthy people, researchers found that the brains of those suffering concussions showed abnormalities four months later. This happened despite the fact that their symptoms had already eased to some degree.

The findings may sway conventional thinking about when it's safe to resume physical activities that could produce another concussion, the study authors said.

"This is a very different population than professional athletes going out and having concussions on a fairly [frequent] basis, as well as jostling their brain around their skull on a regular basis in practice," said study author Andrew Mayer, an associate professor of translational neuroscience at the Mind Research Network in Albuquerque, N.M. It's hard to predict an outcome based on these findings, he said, "but just because you feel you're healed doesn't mean you are."

The study, which was funded by the U.S. National Institutes of Health, is published in the Nov. 20 online edition of the journal Neurology.

Considered a mild traumatic brain injury that occurs from a sudden blow to the head or body, a concussion has symptoms that range from headache and blurry vision to difficulties in sleeping or thinking clearly. Most occur without losing consciousness, according to the U.S. Centers for Disease Control and Prevention.

Mayer and his team matched 50 patients with mild concussions to 50 healthy people of similar age and education levels. They tested all participants in memory and thinking skills, as well as other symptoms such as anxiety and depression.

Special brain scans using technology that is not available in standard brain scans were also given. All tests and scans were repeated two weeks after the concussion, and again four months later.

While concussion symptoms were reduced by up to 27 percent four months after injury, brain scans of those with concussions showed abnormalities in the frontal cortex area of both sides of the brain. These abnormalities may have resulted from changes in location of fluid around brain cells or changes in the shape of certain brain cells in response to damage, Mayer explained.

The findings, he noted, suggest that the recommendation that athletes suffering concussions should refrain from play for one to two weeks may not be sufficient.

"In one or two weeks, most people typically report feeling better," he said. "But when we start talking about it in an analogy of a burn or knee injury, it becomes a little more clear when the doctor says we need to wait a bit longer [to return to prior activities]. It makes sense that the brain would be similar to those tissue types," added Mayer.

Kenneth Podell, co-director of the Houston Methodist Concussion Center, said the study strengthens the understanding that physical changes within the brain after concussion are separate from mental symptoms. But Podell, who was not involved in the research, added that the study couldn't offer implications for potential long-term concussion effects such as depression or dementia.

"Everyone seen at four months should be followed in another four, six or eight months and then re-scanned," he said. "One of the biggest problems we have looking at concussions is we try to predict long-term effects from short-term findings. This injury is very difficult to commit the type of resources needed to do that kind of very expensive and time-consuming study."

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