Health and Medical News and Resources

General interest items edited by Janice Flahiff

Human Brain Is Divided On Fear and Panic: Different Areas of Brain Responsible for External, Internal Threats

From the 4 February 2013 article at Science Daily

Feb. 4, 2013 — When doctors at the University of Iowa prepared a patient to inhale a panic-inducing dose of carbon dioxide, she was fearless. But within seconds of breathing in the mixture, she cried for help, overwhelmed by the sensation that she was suffocating.

The patient, a woman in her 40s known as SM, has an extremely rare condition called Urbach-Wiethe disease that has caused extensive damage to the amygdala, an almond-shaped area in the brain long known for its role in fear. She had not felt terror since getting the disease when she was an adolescent.

In a paper published online Feb. 3 in the journal Nature Neuroscience, the UI team provides proof that the amygdala is not the only gatekeeper of fear in the human mind. Other regions — such as the brainstem, diencephalon, or insular cortex — could sense the body’s most primal inner signals of danger when basic survival is threatened.

“This research says panic, or intense fear, is induced somewhere outside of the amygdala,” says John Wemmie, associate professor of psychiatry at the UI and senior author on the paper. “This could be a fundamental part of explaining why people have panic attacks.

nterestingly, the amygdala-damaged patients had no fear leading up to the test, unlike the healthy participants, many who began sweating and whose heart rates rose just before inhaling the carbon dioxide. That, of course, was consistent with the notion that the amygdala detects danger in the external environment and physiologically prepares the organism to confront the threat.

“Information from the outside world gets filtered through the amygdala in order to generate fear,” Feinstein says. “On the other hand, signs of danger arising from inside the body can provoke a very primal form of fear, even in the absence of a functioning amygdala.”

 

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February 8, 2013 Posted by | Psychiatry | , , | 1 Comment

Eat to Dream: Study Shows Dietary Nutrients Associated With Certain Sleep Patterns

From the 6 February 2013 article at Science Daily

You are what you eat,” the saying goes, but is what you eat playing a role in how much you sleep? Sleep, like nutrition and physical activity, is a critical determinant of health and well-being. With the increasing prevalence of obesity and its consequences, sleep researchers have begun to explore the factors that predispose individuals to weight gain and ultimately obesity. Now, a new study from the Perelman School of Medicine at the University of Pennsylvania shows for the first time that certain nutrients may play an underlying role in short and long sleep duration and that people who report eating a large variety of foods — an indicator of an overall healthy diet — had the healthiest sleep patterns.

..

The authors found that total caloric intake varied across groups. Short sleepers consumed the most calories, followed by normal sleepers, followed by very short sleepers, followed by long sleepers. Food variety was highest in normal sleepers, and lowest in very short sleepers. Differences across groups were found for many types of nutrients, including proteins, carbohydrates, vitamins and minerals.

In a statistical analysis, the research team found that there were a number of dietary differences, but these were largely driven by a few key nutrients. They found that very short sleep was associated with less intake of tap water, lycopene (found in red- and orange-colored foods), and total carbohydrates, short sleep was associated with less vitamin C, tap water, selenium (found in nuts, meat and shellfish), and more lutein/zeaxanthin (found in green, leafy vegetables), and long sleep was associated with less intake of theobromine (found in chocolate and tea), dodecanoic acid (a saturated fat) choline (found in eggs and fatty meats), total carbohydrates, and more alcohol.

“Overall, people who sleep 7 — 8 hours each night differ in terms of their diet, compared to people who sleep less or more. We also found that short and long sleep are associated with lower food variety,” said Dr. Grandner. “What we still don’t know is if people altered their diets, would they be able to change their overall sleep pattern? This will be an important area to explore going forward as we know that short sleep duration is associated with weight gain and obesity, diabetes, and cardiovascular disease. Likewise, we know that people who sleep too long also experience negative health consequences. If we can pinpoint the ideal mix of nutrients and calories to promote healthy sleep, the healthcare community has the potential to make a major dent in obesity and other cardiometabolic risk factors.”

 

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February 8, 2013 Posted by | Medical and Health Research News, Nutrition | , , , , | 1 Comment

Smoking Marijuana Associated With Higher Stroke Risk in Young Adults

Cannabis and pipe

Cannabis and pipe (Photo credit: Wikipedia)

 

From the 6 February 2013 article at Science Daily

 

Marijuana, the most widely used illicit drug, may double stroke risk in young adults, according to research presented at the American Stroke Association’s International Stroke Conference 2013.

In a New Zealand study, ischemic stroke and transient ischemic attack (TIA) patients were 2.3 times more likely to have cannabis, also known as marijuana, detected in urine tests as other age and sex matched patients, researchers said.

“This is the first case-controlled study to show a possible link to the increased risk of stroke from cannabis,” said P. Alan Barber, Ph.D., M.D., study lead investigator and professor of clinical neurology at the University of Auckland in New Zealand. “Cannabis has been thought by the public to be a relatively safe, although illegal substance. This study shows this might not be the case; it may lead to stroke.”

In previous case reports, ischemic stroke and TIAs developed hours after cannabis use, Barber said. “These patients usually had no other vascular risk factors apart from tobacco, alcohol and other drug usage.”

It’s challenging to perform prospective studies involving illegal substances such as cannabis because “questioning stroke and control patients about cannabis use is likely to obtain unreliable responses,” Barber said.

In the study, the regional ethics committee allowed researchers to use urine samples from other hospitalized patients. But researchers knew only the age, sex and ethnicity for matching due to a lack of consent.

The study provides the strongest evidence to date of an association between cannabis and stroke, Barber said. But the association is confounded because all but one of the stroke patients who were cannabis users also used tobacco regularly.

“We believe it is the cannabis and not tobacco,” said Barber, who hopes to conduct another study to determine whether there’s an association between cannabis and stroke independent of tobacco use. “This may prove difficult given the risks of bias and ethical strictures of studying the use of an illegal substance,” he said. “However, the high prevalence of cannabis use in this cohort of younger stroke patients makes this research imperative.”

Physicians should test young people who come in with stroke for cannabis use, Barber said.

“People need to think twice about using cannabis,” because it can affect brain development and result in emphysema, heart attack and now stroke, he said….

 

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February 8, 2013 Posted by | Medical and Health Research News | , , , | 1 Comment

Why is road safety in the U.S. not on par with Sweden, the U.K., and the Netherlands? Lessons to be learned

From the 6 February 2013 summary at Full Text Reports

Source: University of Michigan Transportation Research Institute

This study compared road safety and related factors in the U.S. with those in Sweden, the United Kingdom, and the Netherlands, in order to identify actions most likely to produce casualty reductions in the U.S. The reviewed topics were basic country statistics, road fatalities and various fatality rates, national road-safety strategies, and selected road-safety issues. The main differences concerned structural and cultural factors (such as vehicle distance driven), and procedural factors (such as road-safety strategies and targets, alcohol-impaired driving, exceeding speed limits, and use of seat belts). The main recommendations for improving road safety in the U.S. are as follows: (1) lower states’ BAC limits to 0.5 g/l and introduce effective random breath testing, (2) reexamine the current speed-limit policies and improve speed enforcement, (3) implement primary seat-belt-wearing laws in each state that would cover both front and rear occupants, and reward vehicle manufacturers for installation of advanced seat-belt reminders, (4) reconsider road-safety target setting so that the focus is on reducing fatalities and not on reducing fatality rate per distance driven, and (5) consider new strategies to reduce vehicle distance driven.

 

February 8, 2013 Posted by | Consumer Safety | , , , | 1 Comment

   

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