Posts tagged TBI
Articles and news from the latest research reports.
From football to flies: lessons about traumatic brain injury
Faced with news of suicides and brain damage in former professional football players, geneticist Barry Ganetzky bemoaned the lack of model systems for studying the insidious and often delayed consequences linked to head injuries.
Then he remembered an unexplored observation from nearly 40 years ago: a sharp strike to a vial of fruit flies left them temporarily stunned, only to recover a short time later. At the time he had marked it only as a curiosity.
Now a professor of genetics at UW–Madison, Ganetzky is turning his accidental discovery into a way to study traumatic brain injury (TBI). He and David Wassarman, a UW professor of cell and regenerative biology, report this week (Oct. 14) in the Proceedings of the National Academy of Sciences on the first glimpses of the genetic underpinnings of susceptibility to brain injuries and links to human TBI.
TBIs occur when a force on the body jostles the brain inside the head, causing it to strike the inside of the skull. More than 1.7 million TBIs occur each year in the United States, about one-third due to falls and the rest mainly caused by car crashes, workplace accidents, and sports injuries. TBIs are also a growing issue in combat veterans exposed to explosions.
In many cases, the immediate effects of TBI are temporary and may seem mild — confusion, dizziness or loss of coordination, headaches, vision problems. But over time, impacts may lead to neurodegeneration and related symptoms, including memory loss, cognitive problems, severe depression, or Alzheimer’s-like dementia. Together TBIs cost tens of billions of dollars annually in medical expenses and indirect costs such as lost productivity.
Though TBIs can be classified from “mild” to “severe” based on symptoms, there is a poor understanding of the underlying medical causes.
“Unlike many important medical problems — high blood pressure, cancer, diabetes, heart disease — where we know something about the biology, we know almost nothing about TBI,” Ganetzky says. “Why does a blow to the head cause epilepsy? Or how does it lead down the road to neurodegeneration? Nobody has answers to those questions — in part, because it’s really hard to study in humans.”
Enter the fruit fly. The fly brain is encased in a hard cuticle analogous to the skull, and the basic mechanisms affecting nervous system function are the same in flies and mammals. In the new study, Ganetzky and Wassarman describe a way to reproducibly inflict traumas that seem to mimic the injuries and symptoms of human TBI.
“Now we have a system where we can look at the variables that are the inputs into TBI and determine the relative contributions of each to the pathological outcomes. That’s the real power of the flies,” says Wassarman.
As with humans, few flies die from the immediate impact. Afterward, though, the treated flies show many of the same physical consequences as humans who sustain concussions or other TBIs, including temporary incapacitation, loss of coordination and activation of the innate immune response in the short term, followed by neurodegeneration and sometimes an early death.
The researchers, led by Rebeccah Katzenberger, senior research specialist in the UW Department of Cell and Regnerative Biology, also found that age seems to play an important role. Older flies are more susceptible than younger ones to the effects of the impact and, Wassarman says, many of the outcomes of TBI are very similar to normal aging processes.
With this model, the researchers say, they can now draw on the vast collection of genetic tools and techniques available for fruit flies to probe the underlying drivers of damage.
“What we really want is to understand the immediate and long term consequences in cellular and molecular terms,” says Ganetzky. “From that understanding we can proceed in a more directed way to diagnostics and therapeutics.”
One of the key things they have already identified is the crucial role genetics plays in determining the outcome of an injury, revealed by the high degree of variability seen among different strains of flies. This finding may explain why all potential TBI drugs to date have failed in clinical trials despite showing promise in individual rodent models.
As Wassarman explains, “The heart of the problem of solving traumatic brain injury is that we’re all different.”
They are continuing to develop the model through large-scale genetic analysis and have already found that different sets of genes correlate with susceptibility in flies of different ages. With their system, they can also examine the effects of repeated injuries.
Ganetzky sees tremendous potential for developing applications from the fly-based approach and the Wisconsin Alumni Research Foundation (WARF) has filed for patent protection on the discovery.
“These exciting findings that we can study traumatic brain injury — a disorder of growing concern for athletes, the military, and parents — in the elegantly simple model of fruit flies is sure to interest those researchers and companies looking to address this concern,” says Jennifer Gottwald, WARF licensing manager. “The use of this model can accelerate the work of the medical research community in finding treatments and therapies to help patients.”
(Source: news.wisc.edu)
Age doesn’t impact concussion symptoms: study
Recent scientific findings have raised the fear that young athletes may fare worse after sustaining a sports-related concussion than older athletes.
Researchers in the Vanderbilt Sports Concussion Center compared symptoms associated with concussion in middle- and high-school aged athletes with those in college-age athletes and found no significant differences between the two age groups.
The study, “Does age affect symptom recovery after sports-related concussion? A study of high school and college athletes,” was published online Sept. 24 ahead of print in the Journal of Neurosurgery: Pediatrics.
Lead authors were Vanderbilt University School of Medicine students Young Lee and Mitchell Odom. Other researchers were Scott Zuckerman, M.D., Gary Solomon, Ph.D., and Allen Sills, M.D.
In this retrospective study, the researchers reviewed a database containing information on pre-concussion and post-concussion symptoms in two different age groups: younger (13-16 years old) and older (18-22 years old). Athletes (92 in each group) were evenly matched with respect to gender, number of previous concussions, and time to the first post-concussion test.
Each athlete completed individual pre- and post-concussion questionnaires that covered a variety of symptoms associated with concussion, some of which were headache, nausea, dizziness, fatigue, sleep problems, irritability and difficulties with concentration or memory. Each athlete’s post-concussion scores were compared to his or her own individual baseline scores.
The number or severity of symptoms cited at baseline and post-concussion showed no significant difference between the two age groups. Symptoms returned to baseline levels within 30 days after concussion in 95.7 percent of the younger athletes and in 96.7 percent of the older athletes.
“In the evaluation of sports-related concussion, it is imperative to parse out different ways of assessing outcomes: neurocognitive scores versus symptom endorsement versus balance issues, school performance, etc,” Zuckerman said.
“It appears that symptoms may not be a prominent driver when assessing outcomes of younger versus older athletes. We hope that our study can add insight into the evaluation of youth athletes after sports-related concussion.”
(Source: news.vanderbilt.edu)
Stem cells help repair traumatic brain injury by building a “biobridge”
University of South Florida researchers have suggested a new view of how stem cells may help repair the brain following trauma. In a series of preclinical experiments, they report that transplanted cells appear to build a “biobridge” that links an uninjured brain site where new neural stem cells are born with the damaged region of the brain.
Their findings were recently reported online in the peer-reviewed journal PLOS ONE.
“The transplanted stem cells serve as migratory cues for the brain’s own neurogenic cells, guiding the exodus of these newly formed host cells from their neurogenic niche towards the injured brain tissue,” said principal investigator Cesar Borlongan, PhD, professor and director of the USF Center for Aging and Brain Repair.
Based in part on the data reported by the USF researchers in this preclinical study, the U.S. Food and Drug Administration recently approved a limited clinical trial to transplant SanBio Inc’s SB632 cells (an adult stem cell therapy) in patients with traumatic brain injury.
Stem cells are undifferentiated, or blank, cells with the potential to give rise to many different cell types that carry out different functions. While the stem cells in adult bone marrow or umbilical cord blood tend to develop into the cells that make up the organ system from which they originated, these multipotent stem cells can be manipulated to take on the characteristics of neural cells.
To date, there have been two widely-held views on how stem cells may work to provide potential treatments for brain damage caused by injury or neurodegenerative disorders. One school of thought is that stem cells implanted into the brain directly replace dead or dying cells. The other, more recent view is that transplanted stem cells secrete growth factors that indirectly rescue the injured tissue.
The USF study presents evidence for a third concept of stem-cell mediated brain repair.
The researchers randomly assigned rats with traumatic brain injury and confirmed neurological impairment to one of two groups. One group received transplants of bone marrow-derived stem cells (SB632 cells) into the region of the brain affected by traumatic injury. The other (control group) received a sham procedure in which solution alone was infused into the brain with no implantation of stem cells.
At one and three months post-TBI, the rats receiving stem cell transplants showed significantly better motor and neurological function and reduced brain tissue damage compared to rats receiving no stem cells. These robust improvements were observed even though survival of the transplanted cells was modest and diminished over time.
The researchers then conducted a series of experiments to examine the host brain tissue.
At three months post-traumatic brain injury, the brains of transplanted rats showed massive cell proliferation and differentiation of stem cells into neuron-like cells in the area of injury, the researchers found. This was accompanied by a solid stream of stem cells migrating from the brain’s uninjured subventricular zone — a region where many new stem cells are formed – to the brain’s site of injury.
In contrast, the rats receiving solution alone showed limited proliferation and neural-commitment of stem cells, with only scattered migration to the site of brain injury and virtually no expression of newly formed cells in the subventricular zone. Without the addition of transplanted stem cells, the brain’s self-repair process appeared insufficient to mount a defense against the cascade of traumatic brain injury-induced cell death.
The researchers conclude that the transplanted stem cells create a neurovascular matrix that bridges the long-distance gap between the region in the brain where host neural stem cells arise and the site of injury. This pathway, or “biobridge,” ferries the newly emerging host cells to the specific place in the brain in need of repair, helping promote functional recovery from traumatic brain injury.
Fattah Introduces House Resolution Recognizing World Alzheimer’s Month
Congressman Chaka Fattah (PA-02), a Congressional champion of research and funding for brain-related diseases, introduced a resolution Friday in the U.S. House of Representatives recognizing September as World Alzheimer’s Month. Worldwide, more than 35 million people suffer from Alzheimer’s, and in the United States more than five million individuals live with the debilitating disease.
“The impact of Alzheimer’s is too great for us not to pour more energy and funding into finding a cure for this debilitating disease,” Fattah said. “Beyond the millions worldwide and here at home who suffer from the disease, it puts a significant toll on the millions more family and friends who care for loved ones living with Alzheimer’s and dementia. We must continue to rally stakeholders around the world in the effort to prevent and treat Alzheimer’s.”
The resolution, H. Res. 364 supports the goals of World Alzheimer’s Month: to increase awareness about the disease, its impact on the lives of those affected by it, and the efforts of those seeking to cure Alzheimer’s. It also acknowledges the progress and improvements neurological research has made in the diagnosis and treatment of Alzheimer’s and other forms of dementia.
"As World Alzheimer’s Awareness Month comes to an end, it’s worth remembering that for millions of families across the country, every month is Alzheimer’s month," said George Vradenburg, chairman and co-founder of USAgainstAlzheimer’s. "However, with continued leadership from members of Congress like Rep. Chaka Fattah (PA-02) and others, we can secure the funding resources necessary to stop this disease by 2025."
Fattah added: “This month and every month we must continue to work to elevate the issue, seek new early prevention and treatment strategies, and work towards ultimately finding a cure. We know that neurological research advances this progress, and brings us ever closer to a cure.”
Throughout September, Congressman Fattah continued his work heightening awareness of Alzheimer’s and other neurological diseases. On Saturday, Fattah addressed a day-long conference on Traumatic Brain Injury (TBI) at the University of Pennsylvania. Earlier in the month, Fattah spoke at a California Mental Health Symposium that helped raised more than $2.8 million for research and education.
Fattah is the Ranking Democrat on the House Appropriations Committee’s Subcommittee on Commerce, Justice, Science and Related Agencies, which oversees funding for a significant amount of government-sponsored research. In 2011, Fattah created the Fattah Neuroscience Initiative (FNI) to expand the dialogue around brain diseases and foster cross-sector collaboration for research and funding opportunities.
Soldiers with blast injuries suffer pituitary hormone problems
Researchers studying British soldiers who fought in Afghanistan have highlighted hormonal problems that commonly result from blast injuries.
Soldiers with injuries affecting the pituitary gland may suffer psychological and metabolic symptoms which impede their recovery.
The researchers, from Imperial College London and the Royal Centre for Defence Medicine, say identifying these sufferers will enable them to receive appropriate hormone replacement therapy.
The research was funded by the Medical Research Council is published in the journal Annals of Neurology.
The study looked at 19 British soldiers with moderate to severe brain injury caused by blasts from improvised explosive devices (IEDs) while on duty in Afghanistan, and a group of 39 individuals with moderate to severe traumatic brain injuries caused by road traffic accidents, falls and assaults.
It found that a much higher proportion of soldiers with blast injuries had pituitary hormone problems (32 per cent) than in the non-blast control group (2.6 per cent).
One in five of the soldiers ended up receiving hormone treatment with growth hormone, testosterone and/or hydrocortisone – a replacement for the stress hormone cortisol.
The study also showed that the soldiers who had pituitary dysfunction following blast injury had more severe damage to white matter connections within the brain, and more severe cognitive problems, such as being slow in processing information, than those who did not have hormone problems.
The recent conflicts in Iraq and Afghanistan have seen rapid advances in personal protective equipment and in the medical management of severe trauma. These gains have meant that increasing numbers of soldiers are surviving previously fatal and complex injuries.
Injuries caused by IEDs are so numerous that they have been called the ‘signature injury’ of these conflicts. Between December 2009 and March 2012, 183 UK soldiers survived a moderate to severe blast traumatic brain injury in Afghanistan. The number of such injuries among US troops is much higher. The complex physical forces involved in a blast have led to much speculation about how the blast wave itself causes brain injury.
Dr Tony Goldstone, from the MRC Clinical Sciences Centre at Imperial College London, who led the study, said: “This study was set up to see if there were facets unique to the kind of trauma caused to the brain by IEDs. We found that there was a high prevalence of hormonal problems in soldiers with these kinds of injuries.
“This study involved a relatively small number of soldiers, and so assessment of additional patients will be needed to confirm such a prevalence rate. However the results do emphasise the importance of actively screening for pituitary problems in all soldiers and others who have had moderate to severe brain injury from exposure to blast. This will enable identification of those who may benefit from hormonal treatments to aid their rehabilitation, recovery and quality of life.”
The patients were treated in the multi-disciplinary traumatic brain injury clinic at the Imperial Centre for Endocrinology at Imperial College Healthcare NHS Trust and scanned at the Computational, Cognitive and Clinical Neuroimaging Laboratory at Imperial College London by Professor David Sharp and Major David Baxter.
Air Marshal Paul Evans, Surgeon General said: “I fully support the research that has been undertaken by Imperial College London and the Ministry of Defence. As Surgeon General, I am committed to ensuring Service personnel benefit from the latest advances in medical research and we continue to conduct research into traumatic brain injury with colleagues at Imperial College London as well as our US and other NATO partners. A Defence Medical Services working group identifies priority areas for TBI research and MOD policy continues to be reviewed in light of emerging best practice. Working in partnership will ensure our personnel benefit as well as enable best practice to be shared between the MOD and NHS.”
Professor David Lomas, Chair of the MRC’s Population and Systems Medicine Board, which funded the research, said: “Trauma is a serious health problem that has a major impact on people in both a civilian and military setting. By linking academic and military research programmes through studies such as this we will build a greater understanding of acute trauma that will inform future approaches to trauma management, to ensure that people suffering major injury receive the most advanced specialist care.”
New approach helps those with traumatic brain injury
Greg Noack was 24 when he moved from Ontario to Victoria, B.C. He had just graduated from college and was looking forward to a fresh start.
One early morning in 1996, as he was returning home from his graveyard shift at the hotel, Noack was attacked from behind by a group of men.
He doesn’t remember being struck on the head. He does remember waking from a 15-day coma to learn he had suffered a traumatic brain injury (TBI).
Noack, through the care of his health-care team, relearned how to walk, write, and feel particular emotions.
“I was enamoured by what my therapists were able to do for me,” said Noack. “I was lucky that I got back most of my function.”
Three years post-injury, Noack enrolled in Sault College’s Occupational Therapist Assistant/Physical Therapist Assistant Program and graduated with honours.
Shortly after, Noack was hired by the Toronto Rehab Acquired Brain Injury Rehab team as an occupational therapist assistant and later became a rehab therapist.
Most recently, he was seconded to Dr. Robin Green’s traumatic brain injury research team.
Dr. Green, Senior Scientist and Neuropsychologist, Toronto Rehab and Canada Research Chair in Traumatic Brain Injury, and her Toronto Rehab team have been studying impediments to brain injury recovery as well as treatments to offset the impediments.
Dr. Green’s work suggests that moderate-severe TBI may be a progressive neurological disorder –a whole new way of perceiving the condition.
“What may be occurring after a serious brain injury,” said Dr. Green, “is that damaged tissue is leaving healthy areas of the brain disconnected and under stimulated. Over time, healthy areas may deteriorate.”
Importantly, they discovered that in people with chronic moderate-severe TBI, environmental enrichment – increased physical, social and cognitive stimulation - can offset this deterioration.
Her research paper, entitled “Environmental enrichment may protect against hippocampal atrophy in the chronic stages of traumatic brain injury,” was published September 24 in Frontiers in Human Neuroscience.
In their study of 25 patients with moderate-severe TBI, her team found a positive reaction to environmental enrichment.
Those who reported greater amounts of environmental enrichment – for example, reading, problem solving exercises, puzzles, physical activity, socializing – at 5 months after their injury showed less shrinkage of the hippocampus (associated with memory functioning) from 5 to 28 months post-injury.
“People with moderate-severe TBI are commonly unable to return to the same level of engagement in their work, school or social lives as before the injury,” said Dr. Green. “However, those with greater environmental enrichment may be keeping vulnerable areas stimulated. Environmental enrichment is also known to increase production of neurons in the hippocampus and to promote their integration into existing brain networks.”
Based on the findings from their study, Green’s team is now engaged in research designed to proactively offset deterioration, which includes the delivery of environmental enrichment to patients. Noack is instrumental in delivering enriched therapy for TBI patients who are enrolled in one of Dr. Green’s research studies.
“One thing I loved about this study is that it facilitated greater customization of a patient’s care,” said Noack. “I could see how my patients benefited from the increased amount of stimulation through extended therapy.”
“Although the brains of patients are showing negative changes, patients are still showing recovery of their functioning in spite of it,” said Dr. Green. “If we are able to offset the negative brain changes through the treatments we are developing, we may be able to very significantly improve patients’ recovery and the quality of their aging with a brain injury.”
(Source: uhn.ca)
The Concussed Brain at Work: fMRI Study Documents Brain Activation During Concussion Recovery
For the first time, researchers have documented irregular brain activity within the first 24 hours of a concussive injury, as well as an increased level of brain activity weeks later—suggesting that the brain may compensate for the injury during the recovery time.
The findings are published in the September issue of the Journal of the International Neuropsychological Society
Thomas Hammeke, PhD, professor of psychiatry and behavioral medicine at the Medical College of Wisconsin, is the lead author. Collaborators at the Cleveland Clinic; St. Mary’s Hospital in Enid, Okl.; the University of North Carolina; Franklin College in Franklin, Ind., and the Marshfield Clinic in Marshfield, Wis., co-authored the paper.
To study the natural recovery from sports concussion, 12 concussed high school football athletes and 12 uninjured teammates were evaluated at 13 hours and again at seven weeks following concussive injury.
The concussed athletes showed the expected postconcussive symptoms, including decreased reaction time and lowered cognitive abilities. Imaging via fMRI (functional magnetic resonance imaging) showed decreased activity in select regions of the right hemisphere of the brain, which suggests the poor cognitive performance of concussion patients is related to that underactivation of attentional brain circuits.
Seven weeks post-injury, the concussed athletes showed improvement of cognitive abilities and normal reaction time. However, imaging at that time showed the post-concussed athletes had more activation in the brain’s attentional circuits than did the control athletes.
“This hyperactivation may represent a compensatory brain response that mediates recovery,” said Dr. Hammeke. “This is the first study to demonstrate that reversal in activation patterns, and that reversal matches the progression of symptoms from the time of the injury through clinical recovery.”
“Deciding when a concussed player should return to the playing field is currently an inexact science,” said Dr. Stephen Rao, director of the Schey Center for Cognitive Neuroimaging at the Cleveland Clinic and a senior author. “Measuring changes in brain activity during the acute recovery period can provide a scientific basis for making this critical decision.”
Each year, an estimated 3.8 million people sustain a traumatic brain injury (TBI). TBI is a contributing factor to a third of all injury-related deaths in the United States. More than three-quarters of the TBI’s that occur are concussions or other forms of mild TBI, many of which may go undiagnosed.
(Image: Corbis)
Scientists Develop New Way to Measure Cumulative Effect of Head Hits in Football
Scientists at Wake Forest Baptist Medical Center have developed a new way to measure the cumulative effect of impacts to the head incurred by football players.
The metric, called Risk Weighted Cumulative Exposure (RWE), can capture players’ exposure to the risk of concussion over the course of a football season by measuring the frequency and magnitude of all impacts, said senior author of the study Joel Stitzel, Ph.D., chair of biomedical engineering at Wake Forest Baptist and associate head of the Virginia Tech - Wake Forest University School of Biomedical Engineering and Sciences.
The study is published in the current online edition of the Annals of Biomedical Engineering.
Based on data gathered throughout a season of high school football games and practices, the researchers used RWE to measure the cumulative risk of injury due to linear and rotational acceleration separately, as well as the combined probability of injury associated with both.
“This metric gives us a way to look at a large number of players and the hits they’ve incurred while playing football,” Stitzel said. “We know that young players are constantly experiencing low-level hits that don’t cause visible injury, but there hasn’t been a good way to measure the associated risk of concussion.”
Concussion is the most common sports-related head injury, with football players having the highest rate among high school athletes, according to the study. It is estimated that nearly 1.1 million students play high school football in the United States. However, research on the biomechanics of football-related head impacts traditionally has concentrated on the collegiate level rather than on the high school level.
With such a large number of players in the sport, it is critical to understand the risk associated with different levels of impact and accurately estimate cumulative concussion risk over the course of a practice, game, season or lifetime, Stitzel said.
In the Wake Forest Baptist study, the researchers measured the head impact exposure in 40 high school football players by using sensors placed in their helmets to record linear and rotational acceleration. A total of 16,502 impacts were collected over the course of one football season and the data were analyzed as a group and as individual players.
Impacts were weighted according to the associated risk from linear acceleration and rotational acceleration alone, as well as to the combined probability of injury associated with both. This is an improved method of capturing the cumulative effects from each impact because it accounts for nonlinear relationships between impact magnitude and the associated risk of injury, Stitzel said.
“All hits involve both linear and rotational acceleration, but rotation coveys the idea that your head is pivoting about the neck whereas linear acceleration is experienced from a direct blow in more of a straight line through the center of mass of the head,” Stitzel said.
The median impact for each player ranged from 15.2 to 27.0 g, with an average value of 21.7 g, which shows the wide variability in the force of impacts.
The study found that impact frequency was greater during games (15.5) than during practices (9.4). However, overall exposure over the course of the season was greater during practices.
This information may help teams reduce exposure to head impacts during practices by teaching proper tackling techniques that could reduce exposure to impacts that may result in a higher concussion rate, the researchers reported.
Additionally, the study found a wide variation in player exposure within the team, with a 22-fold variation in the exposure per impact for practices and a 47-fold variation in the exposure for impact for games.
Studies like this are vital to understanding the biomechanical basis of head injuries related to football, Stitzel said. The metric fully captures a player’s exposure over the course of the season and will be used in conjunction with other pre- and post-season evaluations, including MRI and neurological tests conducted as part of this study.
The research team hopes that this work may ultimately improve helmet safety and design to make football a safer sport.
(Image: Getty Images)
Concussion Patients Show Alzheimer’s-like Brain Abnormalities
The distribution of white matter brain abnormalities in some patients after mild traumatic brain injury (MTBI) closely resembles that found in early Alzheimer’s dementia, according to a new study published online in the journal Radiology.
“Findings of MTBI bear a striking resemblance to those seen in early Alzheimer’s dementia,” said the study’s lead author, Saeed Fakhran, M.D., assistant professor of radiology in the Division of Neuroradiology at the University of Pittsburgh School of Medicine. “Additional research may help further elucidate a link between these two disease processes.”
MTBI, or concussion, affects more than 1.7 million people in the United States annually. Despite the name, these injuries are by no means mild, with approximately 15 percent of concussion patients suffering persistent neurological symptoms.
“Sleep-wake disturbances are among the earliest findings of Alzheimer’s patients, and are also seen in a subset of MTBI patients,” Dr. Fakhran said. “Furthermore, after concussion, many patients have difficulty filtering out white noise and concentrating on the important sounds, making it hard for them to understand the world around them. Hearing problems are not only an independent risk factor for developing Alzheimer’s disease, but the same type of hearing problem seen in MTBI patients has been found to predict which patients with memory problems will go on to develop Alzheimer’s disease.”
For the study, Dr. Fakhran and colleagues set out to determine if there was a relationship between white matter injury patterns and severity of post-concussion symptoms in MTBI patients with normal findings on conventional magnetic resonance imaging (MRI) exams. The researchers studied data from imaging exams performed on 64 MTBI patients and 15 control patients, using an advanced MRI technique called diffusion tensor imaging, which identifies microscopic changes in the brain’s white matter.
The brain’s white matter is composed of millions of nerve fibers called axons that act like communication cables connecting various regions of the brain. Diffusion tensor imaging produces a measurement, called fractional anisotropy, of the movement of water molecules along axons. In healthy white matter, the direction of water movement is fairly uniform and measures high in fractional anisotropy. When water movement is more random, fractional anisotropy values decrease.
Of the MTBI patients, 42 (65.6 percent) were men, and the mean age was 17. Sports injury was the reason for concussion in two-thirds of the patients. All patients underwent neurocognitive evaluation with Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT). The researchers analyzed correlation between fractional anisotropy values, the ImPACT total symptom score, and findings of sleep-wake disturbances.
Sleep-wake disturbances are among the most disabling post-concussive symptoms, directly decreasing quality of life and productivity and magnifying post-concussion memory and social dysfunction.
The results showed a significant correlation between high ImPACT total symptom score and reduced fractional anisotropy at the gray-white junction, most prominently in the auditory cortex. Significantly decreased fractional anisotropy was found in patients with sleep-wake disturbances in the parahippocampal gyri relative to patients without sleep-wake disturbances.
“When we sleep, the brain organizes our experiences into memories, storing them so that we can later find them,” Dr. Fakhran said. “The parahippocampus is important for this process, and involvement of the parahippocampus may, in part, explain the memory problems that occur in many patients after concussion.”
According to Dr. Fakhran, the results suggest that the true problem facing concussion patients may not be the injury itself, but rather the brain’s response to that injury.
“Traditionally, it has been believed that patients with MTBI have symptoms because of abnormalities secondary to direct injury,” he said. “Simply put, they hit their head, damaged their brain at the point of trauma and thus have symptoms from that direct damage. Our preliminary findings suggest that the initial traumatic event that caused the concussion acts as a trigger for a sequence of degenerative changes in the brain that results in patient symptoms and that may be potentially prevented. Furthermore, these neurodegenerative changes are very similar to those seen in early Alzheimer’s dementia.”
The researchers hope that these findings may lead to improved treatments in the future.
“The first step in developing a treatment for any disease is understanding what causes it,” Dr. Fakhran said. “If we can prove a link, or even a common pathway, between MTBI and Alzheimer’s, this could potentially lead to treatment strategies that would be potentially efficacious in treating both diseases.”
(Source: prweb.com)
When Head Meets Soccer Ball, How Does Your Brain Fare?
Soccer players who frequently head-butt the ball—a commonly used tactic for passing or scoring in a game—may be risking brain injury, memory loss, and impaired cognitive ability, according to a study published in the journal Radiology.
Brain injury and the lasting effects of concussion in sport have become a major health issue in recent years, especially in such hard-hitting sports as American football. Although the thump of a soccer ball on a forehead seems fairly innocuous, compared with a crashing tackle on the three-yard line, a soccer player may “head” the ball hundreds or even thousands of times during the course of the season. The cumulative effect of many “sub-concussive” blows to the brain has been unknown and unstudied until now.
"We chose to study soccer because it is the world’s most popular sport," says the report’s lead author Michael Lipton, associate director of the Gruss Magnetic Resonance Research Center at the Albert Einstein College of Medicine in New York. "It is widely played by millions of people of all ages, including children, and there is concern that heading the ball, an essential part of the game, might cause damage to the brain."
Lipton and his colleagues examined 37 amateur players, all adults, who had played soccer for an average of 22 years each and had played regularly over the previous year. They filled out questionnaires about their playing style and how frequently they headed the ball on the field and in training drills. Then they were given memory tests and highly sophisticated brain scans, using a type of MRI called diffusion-tensor imaging that looks at microscopic changes in the white matter in the brain. White matter is the tissue that conveys messages from one region of the brain to another.
The researchers found that players had to head the ball a certain number of times in a season before white matter abnormalities started to appear on imaging. The threshold varied from player to player but was generally in the range of 900 to 1,500 headers in a season. Beyond this threshold, the brain abnormalities quickly became more apparent. Those who headed the ball more than 1,800 times in a season scored measurably worse on memory tests than those who had headed the ball less frequently. The difference in scores was in the range of 10 to 20 percent.
"To put this into perspective I should make it clear that all of these players’ functions were still within norms," said Lipton. "These are all basically functional young professionals and students."
So, should soccer players—and parents of young soccer players—be worried?
"All we have at this point is some evidence that shows an association between heading and what looks like brain injury. However, we do not yet have the type of data that permits us to prove a causal role for heading or to generalize our findings to other specific individuals. In the meantime, controlling the amount of heading that people do may provide an approach for preventing brain injury as a consequence of heading."
"I should emphasize that we very much see soccer as an excellent source of beneficial physical activity. This should not be curtailed. Our message is to understand the role of heading in the game and look at how we can enhance the safety of soccer play and facilitate its expansion."