People who have had head injuries report more violent behavior

ScienceDaily (June 2, 2011) — Young people who have sustained a head injury during their lifetime are more likely to engage in violent behavior, according to an eight-year study from the University of Michigan School of Public Health.

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Further, the research found that young people who suffered a recent head injury (within a year of being questioned for the study) were even more likely to report violent behavior.

The report, which appears in the current issue of the journal Pediatrics, is one of the few studies to examine long-term effects of head injuries in a general population of young adults. Most other similar studies were conducted in prison populations.

There's been a recent blitz of media and research attention regarding youth, college and professional athletes who suffer head injuries and concussions while playing. This study is broader, but confirms previous findings about the connection between violence and head injuries, says lead author Sarah Stoddard, a research assistant professor at the School of Public Health.

"These are not necessarily sports-playing injuries," said Stoddard, who also is a research fellow at the U-M School of Nursing. "They could be from a car accident or from previous violent behavior, but it does support some of the sports research that's been going on with concussions."

Stoddard used data from the School of Public Health's Flint Adolescent Study, which looks at many issues regarding urban youth. Marc Zimmerman, professor of public health and chair of the U-M Department of Health Behavior and Health Education, is the principal investigator on that study.

The researchers followed a group of ninth-graders from four schools in Flint, Mich., into young adulthood. They conducted annual interviews over eight years. In years five and six, participants were asked if they had ever sustained a head injury. Those who said yes -- about 23 percent -- reported more violent behavior in year eight of the study.

Moreover, Stoddard and Zimmerman examined the proximal relationship between a head injury and violent behavior and found that an injury reported in year seven of the study predicted violent behavior in year eight.

"We found that the link between a head injury and later violence was stronger when a head injury was more recent, even after controlling for other factors including previous violent behavior," Stoddard said.

The results also suggest that adolescents and young adults who have suffered a head injury that did not interfere with their ability to participate in an hour-long interview may still experience significant adverse developmental or behavioral effects.

The researchers defined a head injury as having been knocked unconscious or sustaining a concussion or a fractured skull.

Traumatic brain injury is a serious public health issue, they say. An estimated 1.7 million people annually sustain a TBI, and that only includes people who get medical care, so the number is likely much higher. Roughly 75 percent of head injuries are mild and many do not receive medical attention, but any TBI disrupts the function of the brain. Long-term impact can include changes in cognition, language and emotion, including irritability, impulsiveness and violence.

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How does anesthesia disturb self-perception?

ScienceDaily (Jan. 24, 2011) — An Inserm research team in Toulouse, led by Dr Stein Silva (Inserm Unit 825 "Brain imaging and neurological handicaps"), working with the "Modelling tissue and nociceptive stress" Host Team (MATN IFR 150), were interested in studying the illusions described by many patients under regional anaesthetic. In their work, to be published in the journal Anesthesiology, the researchers demonstrated that anaesthetising an arm affects brain activity and rapidly impairs body perception.

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The ultimate aim of the work is to understand how neuronal circuits are reorganised at this exact moment in time and to take advantage of anaesthesia to reconfigure them correctly following trauma. This would allow anaesthetic techniques to be used in the future to treat pain described by amputated patients in what are known as "phantom limbs."

Neuroscience research in recent years has shown that the brain is a dynamic structure. Phenomena such as learning, memorising or recovery from stroke are made possible by the brain's plastic properties. Brain plasticity does not, however, always have a beneficial effect.

For example, some amputated patients suffering from chronic pain (known as phantom limb pain) feel as though their missing limb were "still there." Such "phantom limb" illusions are related to the appearance in the brain of incorrect representations of the missing body part.

Persons under regional anaesthetic describe these very same false images.

Based on these observations, Inserm's researchers wished to discover whether anaesthesia could, in addition to fulfilling its primary function, induce comparable phenomena in the brain. If this were so, anaesthetics could be used as new therapeutic tools capable of modulating brain activity.

With this in mind, a team headed by Dr Stein Silva monitored 20 patients who were to have one of their arms anaesthetised before surgery. The patients were shown 3D images of the hand, shot from different angles, and their ability to distinguish the right hand from the left was assessed. Results showed how anaesthesia affected the patients' ability to perceive their body correctly.

The researchers observed three phenomena based on these tests:

All the patients described false sensations in their arm (swelling, difference in size and shape, imagined posture). In general, patients under anaesthetic took longer to distinguish between a left and right hand and made far more mistakes than persons not under anaesthetic. The best results were obtained when the anaesthetised limb was visible.

In other words, anaesthetising the hand (peripheral deafferentation ) modifies brain activity and rapidly changes the way we perceive the outside world and our own body. The teams are now using functional brain imaging to characterise the regions concerned in the brain. They also hope that it will be possible to use anaesthesia for therapeutic purposes in the future by modulating post-lesional plasticity (chronic pain in amputated patients, improved recovery in those suffering from brain lesions).

Inserm researcher Stein Silva, an anaesthetist and the chief author of the study, believes that it will no doubt be necessary to develop new anaesthetic techniques to inhibit or directly stimulate the brain images associated with painful phenomena.

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A novel function of anti-diuretic hormone vasopressin in the brain

ScienceDaily (Jan. 20, 2011) — The anti-diuretic hormone "vasopressin" is released from the brain, and known to work in the kidney, suppressing the diuresis. Now, a Japanese research team led by Professor Yasunobu Okada, Director-General of National Institute for Physiological Sciences (NIPS), and Ms. Kaori Sato, a graduate student of The Graduate University for Advanced Studies, has clarified the novel function of "vasopressin" that works in the brain, as well as in the kidney via the same type of the vasopressin receptor, to maintain the size of the vasopressin neurons.

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It might be a useful result for clarification of the condition of cerebral edema which swells along with the brain trauma or the cerebral infarction, and for its treatment method development. This result of the study is reported in the Science Signaling magazine.

The research team focused on the vasopressin neurons which exist in a hypothalamus of the brain. The vasopressin is essentially released from the vasopressin neurons into blood circulation and acts on the kidney as anti-diuretic, when the blood plasma becomes more concentrated. In contrast, they ascertained that the vasopressin neurons release the vasopressin into the brain, not in blood, when the surrounding body fluid becomes more diluted than usual. Usually, the more diluted the body fluid becomes, the bigger the neuronal cell swells. However, their finding shows that the vasopressin in the brain maintains the size of the vasopressin neurons even when the body fluid becomes more diluted. In addition, it was clarified that the vasopressin sensor protein (receptor) which was currently considered to be only in the kidney, was related to this function in the brain.

This study became possible by labeling vasopressin neurons of the rat brain hypothalamus with green fluorescent protein (GFP)．(The transgenic rat was developed by Professor Yoichi Ueta; University of Occupational and Environmental Health, Japan.)

Professor Okada says that "It is a surprising result that the same type of the vasopressin receptor as the kidney exists in the brain and the vasopressin works on it. It can be expected to clarify the condition of cerebral edema which swells along with the brain trauma or the cerebral infarction, and to develop its treatment method.

This result is supported by Grants-in-Aid for Scientific Research, the MEXT, Japan.

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Culprit found for increased stroke injury with diabetes

ScienceDaily (Jan. 24, 2011) — Strokes are a leading cause of mortality and adult disability. Those that involve intracerebral hemorrhage (bleeding in the brain) are especially deadly, and there are no effective treatments to control such bleeding. Moreover, diabetes and hyperglycemia (high blood glucose levels) are associated with increases in bleeding during hemorrhagic stroke and worse clinical outcomes.

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But Joslin Diabetes Center researchers now have identified one key player that contributes to this increased bleeding, a discovery that may pave the way toward treatments that minimize adverse stroke outcomes both for people with pre-existing diabetes and those with hyperglycemia identified at the time of stroke.

Studies in the lab of Joslin Investigator Edward Feener, Ph.D., pinpointed a new mechanism involving a protein called plasma kallikrein that interferes with the normal clotting process in the brain following blood vessel injury with diabetes. Their work is reported online in the journal Nature Medicine.

The scientists began by injecting a small amount of blood into the brains of rats with diabetes and of control animals without diabetes. The difference was dramatic -- the diabetic animals bled over a much greater area of the brain.

Work in the Feener lab had previously implicated plasma kallikrein in diabetic eye complications. When the experimenters pre-treated the diabetic animals with a molecule that inhibits the protein's effects, brain damage from the blood injections dropped to levels similar to that in the control animals. Conversely, when pure plasma kallikrein was injected into the brain, it produced little impact on the control animals but rapidly increased major bleeding in the animals with diabetes.

Further studies by the Joslin researchers showed that normalizing blood glucose levels in diabetic animals could block the effect from plasma kallikrein, and that rapidly inducing hyperglycemia in control animals mimicked the effects of diabetes on brain hemorrhage. This suggests that high blood sugar at the time of brain hemorrhage, rather than diabetes per se, is responsible for the increased bleeding.

"Given the prevalence of strokes and the damage they inflict, these findings are exciting because they suggest the possibility that rapid control of blood sugar levels may provide an opportunity to reduce intracerebral hemorrhage, which is a clinical situation that has very limited treatment options," says Dr. Feener, who is also an associate professor of medicine at Harvard Medical School. "This work could have broad implications since about half of patients with acute hemorrhagic stroke have hyperglycemia, whether or not they have pre-existing diabetes."

The work also raises the possibility of developing drugs that target plasma kallikrein and may provide protective measures in people with diabetes or others at high risk for stroke. Such drugs might also prove useful for patients suffering from the more common ischemic strokes, which usually begin as blocked vessels in the brain but can transform into hemorrhages.

Surprisingly, while plasma kallikrein has been studied for decades, the Joslin scientists found that the protein boosts brain bleeding through a previously unknown mechanism -- by blocking platelet activation near damaged blood vessels.

Joslin's Jia Liu and Ben-Bo Gao were co-lead authors on the Nature Medicine paper. Other contributors include Joslin's Allen Clermont, and Price Blair and Robert Flaumenhaft of Beth Israel Deaconess Medical Center, and Tamie Chilcote and Sukanto Sinha of ActiveSite Pharmaceuticals. Lead funding came from the National Institutes of Health and the American Heart Association.

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A psychopath lacks empathy just like a person with frontal head injury, study suggests

ScienceDaily (Jan. 25, 2011) — People diagnosed as psychopathic have difficulty showing empathy, just like patients who have suffered frontal head injury. This has been shown in a new study from the University of Haifa. "Our findings show that people who have psychopathic symptoms behave as though they are suffering frontal brain damage," said Dr. Simone Shamay-Tsoory, who conducted the study.

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Psychopathy is a personality disorder that finds expression in extreme anti-social behavior and intentional harm to others, including a lack of compassion and empathy. An existing explanation for such behavior suggests inability to comprehend the existence of emotions in others. However, the fact that many psychopaths act with sophistication and deceit with intention to harm others, indicates that they actually have a good grasp of the mental capacity of others -- and are even capable of using that knowledge in order to cause them harm.

Earlier research by Dr. Shamay-Tsoory has examined individuals with frontal head injury, i.e., damage to parts of the brain that are responsible for emotional functioning. She has shown that people suffering this type of brain damage have difficulty showing empathy. Having observed similar emotional deficiency in psychopathic behavior, she set out to see if there is in fact a similarity between the two cases.

The current study assessed 17 people who had been diagnosed by psychiatrists as psychopathic -- and not suffering from any known brain damage; and another 25 individuals suffering frontal lobe injury. Each of the participants underwent a computerized test examining cognitive ability to recognize feelings in another and the ability to demonstrate empathy for another's emotions. They were also tested to gage their capacity to understand another's thoughts. The results of these tests showed that both groups demonstrated a similar difficulty in showing empathy, while two control groups of individuals with no known mental disorders or brain damage and individuals with non-frontal brain damage both showed different results with positive empathy capabilities.

"Seeing as psychopathic behavior is similar to that of a person with brain damage, it could be that it could benefit from similar forms of treatment," Dr. Shamay-Tsoory noted.

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New era of advances in brain research: As recording technology rapidly improves, neurons give up their secrets cell by cell

ScienceDaily (Jan. 30, 2011) — Scientists at The Rehabilitation Institute of Chicago (RIC) report that, thanks to improvements in technology and data analysis, our understanding of the functional principles that guide the development and operation of the brain could improve drastically in the next few years. The advances could herald a neuroscientific revolution, much as increasing processor speeds paved the way for the computing revolution of the last half century.

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In the February, 2011 issue of Nature Neuroscience, the researchers, Dr. Ian H. Stevenson and Dr. Konrad P. Kording, performed a meta-analysis of 56 studies conducted since the 1950s (the advent of multi-electrode recordings) in which the activity of neurons was recorded in animals or humans. They found that the number of simultaneously recorded single neurons has grown exponentially since the 1950s, doubling approximately every seven years.

The researchers likened the progress in neuronal recording techniques to Moore's law, which describes the exponential growth of processing speed that has doubled approximately every two years, making computers smaller and technology accessible to more people.

"As it becomes easier for us to access and interpret information coming from the brain, we will be able to better help those with disabilities and conditions of the nervous system," said Dr. Kording. "Our goal is to take what we are learning about how and why the brain works so we can quickly and successfully use it to help patients. By decoding how neurons communicate with each other, we may one day be able to restore connections by conditioning different neurons to talk to each other, or to talk to each other in different ways, thereby restoring ability in our patients."

The "firing" or "spiking" of a neuron is really a signal sent along a gradient to other neurons and throughout the entire nervous system. These signals send messages and convey important information, including representations about the world and messages that control our behaviors and actions.

According to Dr. Kording, "Recording of only a single neuron at a time was possible in the late 1950s. Now, researchers can record activity from hundreds of neurons simultaneously, gathering valuable information about when and why neurons fire or do not fire."

In patients with conditions caused by lost connections in the brain, such as stroke or spinal cord injury, information from the brain sent via neurons cannot get relayed to certain limbs or parts of the body. Researchers at RIC are using data from neurons to pioneer research designed to restore connections and ability using novel technologies. In fact, RIC researchers recently reported that they have identified novel ways of potentially re-routing the flow of information in the nervous system using stimulation technology. Currently, RIC researchers are on the cutting-edge of exploring the use of novel brain-machine interface, functional electronic stimulation and virtual reality technology to restore function in individuals suffering from paralysis caused by spinal cord injuries or stroke.

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Retired NFL players misuse painkillers more than general population, study finds

ScienceDaily (Jan. 30, 2011) — Retired NFL players use painkillers at a much higher rate than the rest of us, according to new research conducted by investigators at Washington University School of Medicine in St. Louis.

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The researchers say the brutal collisions and bone-jarring injuries associated with football often cause long-term pain, which contributes to continued use and abuse of painkilling medications.

The study is published online in the journal Drug and Alcohol Dependence. It involved 644 former NFL players who retired from football between 1979 and 2006. Researchers asked them about their overall health, level of pain, history of injuries, concussions and use of prescription pain pills.

The study found that 7 percent of the former players were currently using painkilling opioid drugs. That's more than four times the rate of opioid use in the general population. Opioids are commonly prescribed for their analgesic, or pain-relieving, properties. Medications that fall within this class of drugs include morphine, Vicodin, codeine and oxycodone.

"We asked about medications they used during their playing careers and whether they used the drugs as prescribed or whether they had ever taken them in a different way or for different reasons," says principal investigator Linda B. Cottler, PhD, professor of epidemiology in psychiatry at Washington University. "More than half used opioids during their NFL careers, and 71 percent had misused the drugs. That is, they had used the medication for a different reason or in a different way than it was prescribed, or taken painkillers that were prescribed for someone else."

Those who misused the drugs during their playing days were more likely to continue misusing them after retiring from football. Some 15 percent of those who misused the drugs as active players still were misusing them in retirement. Only 5 percent of former players who took the drugs as prescribed misused them after they retired from the NFL.

Cottler, director of the Epidemiology and Prevention Research Group in the Department of Psychiatry, says it's not clear from the study whether retired players became dependent on the drugs. What is clear from the survey, she says, is that retired NFL players continue to live with a lot of pain.

"The rate of current, severe pain is staggering," she says. "Among the men who currently use prescription opioids -- whether misused or not -- 75 percent said they had severe pain, and about 70 percent reported moderate-to-severe physical impairment."

Pain was one of the main predictors of current misuse. Another was undiagnosed concussion. Retired NFL players in the study experienced an average of nine concussions each. Some 49 percent had been diagnosed with a concussion at some point during their playing careers, but 81 percent suspected they had concussions that were not diagnosed. Some players believed they may have had up to 200 concussions during their playing days.

"Many of these players explained that they didn't want to see a physician about their concussions at the time," says Simone M. Cummings, PhD, a senior scientist in psychiatry who conducted phone interviews with the former players. "These men said they knew if they reported a concussion, they might not be allowed to play. And if you get taken out of a game too many times, you can lose your spot and get cut from the team."

She says players with suspected-but-undiagnosed concussions reported they borrowed pills from teammates, friends or relatives to treat the pain themselves, thus misusing opioids in an attempt to remain in the NFL. Although 37 percent of the retired players reported that they had received opioids only from a doctor, the other 63 percent who took the drugs during their NFL careers admitted that on occasion they got the medication from someone other than a physician.

Retired players currently misusing opioid drugs also are more likely to be heavy drinkers, according to Cottler.

"So these men are at elevated risk for potential overdose," she says. "They reported more than 14 drinks a week, and many were consuming at least 20 drinks per week, or the equivalent of about a fifth of liquor."

The ESPN sports television network commissioned the study, which also was funded by the National Institute on Drug Abuse. The ESPN program "Outside the Lines" spoke informally to many retired players about their use of painkillers. One reported taking up to 1,000 Vicodin tablets per month. Another reported ingesting 100 pills per day and spending more than $1,000 per week on painkillers.

Former St. Louis Rams offensive lineman Kyle Turley said in a statement to ESPN that he knew of many players who took drugs to help them deal with the pain inflicted by the injuries they sustained in the NFL.

"I know guys that have bought thousands of pills," Turley said. "Tons of guys would take Vicodin before a game."

The researchers say offensive linemen had particularly high rates of use and misuse of opioids.

"The offensive linemen were twice as likely as other players to use or misuse prescription pain medicines during their NFL careers," Cottler says. "In addition, this group tends to be overweight and have cardiovascular problems, so they represent a group of former players whose health probably should be monitored closely."

In fact, Cottler says it would be a good idea to continue monitoring everyone who has played in the NFL. She says this study revealed that some 47 percent of retired players reported having three or more serious injuries during their NFL careers, and 61 percent said they had knee injuries. Over half, 55 percent, reported that an injury ended their careers.

"These are elite athletes who were in great physical condition when their playing careers began," she says. "At the start of their careers, 88 percent of these men said they were in excellent health. By the time they retired, that number had fallen to 18 percent, primarily due to injuries. And after retirement, their health continued to decline. Only 13 percent reported that they currently are in excellent health. They are dealing with a lot of injuries and subsequent pain from their playing days. That's why they continue to use and misuse pain medicines."

Cottler LB (WU), Abdallah AB (WU), Cummings SM (WU), Barr J (ESPN), Banks R (ESPN), Forchheimer R (ESPN). Injury, pain and prescription opioid use among former NFL football players, Drug and Alcohol Dependence, vol. 113(3), Jan. 28, 2011.

This work was commissioned and supported by a grant from ESPN, with additional funding from the National Institute on Drug Abuse of the National Institutes of Health.

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