Study: Traumatic brain injury and dementia in older adults

A study shows that older adults who previously had a traumatic brain injury are at a higher risk of developing dementia.

Traumatic brain injury (TBI) appears to be associated with an increased risk of dementia in adults 55 years and older, according to a study published online by JAMA Neurology.

Controversy exists about whether there is a link between a single TBI and the risk of developing dementia because of conflicting study results. The Centers for Disease Control and Prevention says that Americans 55 years and older account for more than 60 percent of all hospitalizations for TBI, with the highest rates of TBI-related emergency department (ED) visits, inpatient stays and deaths happening among those patients 75 years and older. Therefore, understanding the effects of a recent TBI and the subsequent development of dementia among middle or older adults has important public health implications.

Researchers Raquel C. Gardner, M.D., of the University of California, San Francisco, and colleagues examined the risk of dementia among adults 55 years and older with recent TBI compared with adults with non-TBI body trauma (NTT), which was defined as fractures but not of the head or neck. The study included 164,661 patients identified in a statewide California administrative health database of ED and inpatient visits.

In the study, a total of 51,799 patients with trauma (31.5 percent) had TBI. Of those, 4,361 patients (8.4 percent) developed dementia compared with 6,610 patients (5.9 percent) with NTT. The average time from trauma to dementia diagnosis was 3.2 years and it was shorter in the TBI group compared with the NTT group (3.1 vs. 3.3 years). Moderate to severe TBI was associated with increased risk of dementia at 55 years or older, while mild TBI at 65 years or older increased the dementia risk.

"Whether a person with TBI recovers cognitively or develops dementia, however, is likely dependent on multiple additional risk and protective factors, ranging from genetics and medical comorbidities to environmental exposures and specific characteristics of the TBI itself," the authors note.

Editorial: Role of Big Data in Understanding Late-Life Cognitive Decline

In a related editorial, Steven T. DeKosky, M.D., of the University of Pittsburgh School of Medicine, writes: "In this issue of JAMA Neurology, Gardner and colleagues used a very large database to examine the risk of dementia following significant trauma, specifically whether body trauma (fractures) or traumatic brain injury (TBI) differed in dementia incidence during follow-up."

"Unfortunately, there was not a nontrauma control group included, which may have answered the question of whether NTT (i.e. body trauma itself) raised the risk of dementia significantly above age-equivalent controls without nonbrain trauma (perhaps from inflammation or other complications)," DeKosky continues.

"Judicious use of data by skilled researchers who are familiar with the entire range of dementia research from pathobiology to health care needs will enable us to ask important questions, evolve new or more informed queries, and both lead and complement the translational questions that are before us. Dementia is both a global problem and a pathological conundrum; thus, the complementary use of big data and basic neuroscience analyses offers the most promise," he concludes.

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Timing of traumatic brain injury treatment

This article explains the importance of timely treatment for traumatic brain injury in the hospital / critical care setting.

Researchers at the University of Adelaide have discovered two potential treatments for traumatic brain injury that are most effective when given at different stages after the injury has occurred.

Laboratory studies conducted in the University's School of Medical Sciences have confirmed that changes in brain water channels over time play a critical role in traumatic brain injury.

For his PhD at the University, researcher Dr Joshua Burton tested two compounds that alter the natural flow of water activity in and out of the brain. He found that recovery from brain injury can be greatly assisted when these compounds are given at the right times.

Dr Burton's work could point to the potential development of new drugs as well as new approaches to preventing brain damage and death. The research also has implications for treatment of brain swelling after stroke.

"One of the serious consequences of traumatic brain injury is an increase in brain moisture content and associated brain swelling, which significantly impacts patients' neurological outcomes. This swelling can occur for days after the initial injury and is frequently life-threatening," Dr Burton says.

"The water channels normally function to protect the brain, but in the case of traumatic injury or stroke they become a pathway of vulnerability that allows swelling. Unfortunately, the swelling creates pressure within the skull -- there's nowhere for the brain to expand to -- decreasing oxygen levels and blood to the brain."

Dr Burton has found that applying a drug that closes the water channels can inhibit initial water entry, helping to close the window of vulnerability. A second drug used later in the progression of the injury acts to enhance the water channel activity, letting superfluous moisture out when needed. "By using both of these compounds -- a blocker at the early stage of injury, and an activator at the later stage -- we're able to complement the brain's natural healing processes and maintain a reduced level of swelling," he says.

This work builds on more than a decade of research conducted by the University of Adelaide's Professor Andrea Yool on the water channel proteins known as "aquaporins."

"Dr Burton's work is groundbreaking because it clarifies the roles of aquaporins in the brain during the short and long-term responses to traumatic head injury. This work also demonstrates for the first time that recently discovered drug-like compounds can be used in series to initially reduce water entry and then enhance water exit over time," Professor Yool says.

"Most current therapeutic approaches are limited in their ability to reduce injury-induced brain swelling, and no treatments are available to resolve excess fluid at a later stage. While much more research is needed, there is exciting potential here for new interventions in clinical situations. New approaches that can improve the outlook for patients, especially in the later stages of injury development, would be of great benefit," she says.

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Concussions in the U.S. - Some helpful information on brain injury

This article explains all about concussion in the U.S., how to treat them, and common misconceptions about concussions.

Concussion, sometimes referred to as mild traumatic brain injury, is one of the most commonly encountered sports injuries. Studies vary but rates are estimated at two million sport related concussions per year in the United States. It is also commonly believed that these are under reported injuries due to lack of recognition of the concussion and the desire of athletes to not miss time from their activity.

Research has led to change in our approach to treatment of the injuries. New guidelines do not use a set time away from activity and emphasize a gradual return to play. While concussions often occur from direct contact to the head or face, they may also occur from rotational forces without contact such as a tumbling fall. Although research continues to help understand what happens to the brain in a concussion, it appears that the neurons (brain cells) sustain a small injury that creates an "energy crisis." This generally lasts 7-10 days and physical or cognitive activity during this time period may worsen symptoms and prolong recovery. ...

Collision sports (football, hockey, etc.) generally have the highest overall rates of concussion; however, they can be seen in all sporting activity. Fortunately, the overall rates of concussions are relatively low even in collision sports. Certain risk factors are associated with an increased risk of concussion or prolonged recovery. Genetics, gender, playing position, migraines, history of multiple concussions and mental disorders (depression, anxiety and ADHD) all may play a role in how an athlete is affected by a concussive injury.

However it is still unclear how much influence each of these factors has on an individual athlete's risk. The diagnosis of a concussion can be complex as the signs and symptoms of concussions can be found in many other conditions and there is not a singular test we can use to determine if a concussion has occurred. Sometimes the diagnosis is very straight forward, for example when there has been a brief loss of consciousness, but many times the changes seen in the athlete are very subtle. The diagnosis of a concussion is mainly based on the history and physical examination. Symptoms of a concussion may include headache, dizziness, nausea/vomiting, amnesia, brief loss of consciousness and inability to concentrate. These symptoms may last for several days to a few weeks.

Imaging, CT scan or MRI, rarely indicate concussions, unless there is a finding on examination that suggests a structural injury ( e.g. bleeding or swelling). Newer computerized tests may add value in some cases, but these tests are not used to diagnose concussions and it is unclear if using these tests improve the outcomes of concussed athletes. Previous grading scales used symptoms at the time of the concussion to determine the severity of the concussion. New guidelines now suggest that we not grade concussions at all and that we only determine that a concussion has occurred. The reasoning for this lies in newer research that shows symptoms at the time of the initial injury do not correlate with the severity of the injury and recovery time. Additionally, grading does not change our treatments as resting until symptoms have resolved is the initial treatment regardless of the injury.

Treatment

When an athlete is suspected of having a concussion, they should be removed immediately from competition. Symptoms should be monitored and the athlete should not be returned to competition until they are evaluated by a qualified medical professional. This evaluation should occur as soon as possible. The athlete should be monitored closely for several hours after a concussion. It is important to stress that both physical and mental rest speed the recovery of concussions. It is okay for the athlete to sleep and should avoid over stimulation such as video games or loud crowded activities. Athletes may need to stay out of school or have modified class schedules.

Ask your health care provider for more specific recommendations. Returning the athlete to play starts when the athlete is symptom free. It will take 3-7 days for full return to sports (depending on the sport) with an athlete gradually increasing their activity level every 24 hrs. Returning to class can occur over the same timeframe and athletes should be monitored as well for any increase or recurrence of symptoms. Activity can surface underlying concussion symptoms and athletes should be instructed to notify their coach, trainer or physician if they redevelop any symptoms during the recovery period. This process allows faster and safer return to sporting activity. Computerized neuropsychological testing is sometimes used to help monitor an athlete's progress but is never used on its own to determine a diagnosis or an athlete's readiness to return to play. There are many common misconceptions about concussive injuries.

The following are several myths about concussion:

Every athlete who sustains a hard hit must have a concussion. Although our knowledge about the forces involved in concussion is improving we still have not found a level of force that definitely causes a concussion. At times high forces do not cause an injury and relatively lower ones may. This means that we should not overact to every head impact but also need to listen to athletes who complain of concussive like symptoms after any head contact. Because there is no known force level for concussion in-helmet devices that are marketed to consumers as "concussion alarms," they are not recommended as they will likely lead to both over and under diagnosis of concussive injuries.

Better helmets and mouth guards will prevent concussions. Unfortunately there is no good scientific evidence that helmets of any type (hard shells, soft-padded or head bands) or mouth guards can prevent or reduce the risk of concussions. Hard helmets can reduce the risk of more serious head injuries (bleeding, skull fractures etc.) and should be worn in high risk sports. Mouth guards can prevent dental injuries and should be worn for sports with a high risk of these injuries. Helmet-add ons additionally are not effective in concussion prevention and using these will generally void any warranties associated with the helmet. Risk reduction may be possible in some settings with rule changes (e.g. no hitting from behind in hockey) and behavior changes (e.g. tackling technique in football).

Once you have a concussion you will always be more susceptible to having another one. While there appears to be an increased risk of recurrence in the first few weeks after a concussive injury it is unclear what factors may influence the risk of another injury in the future. Despite being a commonly held belief there is no evidence to suggest that athletes develop a decreasing force threshold after each injury. A few small studies have found the opposite....

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How to treat sleep problems following a concussion

New clinical guidelines have been released regarding how to treat sleep problems in people following a concussion.

The Defense and Veterans Brain Injury Center has released new clinical recommendations and support tools to assist in the identification and treatment of a sleep disturbance occurring in patients after a concussion (mild traumatic brain injury or mTBI). The suite of products assists health care providers in the identification of a sleep problem and provides recommendations for its treatment.
"Sleep disorders are common after a person sustains a concussion," said Col. Sidney Hinds, II, M.D., Defense and Veterans Brain Injury Center's, or DVBIC's, national director. "The prompt identification and treatment of sleep disorders are an important part of the recovery process for concussion. Sleep is critical to the brain's healing and recovery processes. Research shows that if sleep is regular and adequate, restorative processes are promoted." 

Since 2000, more than 300,000 U.S. service members have sustained a traumatic brain injury.

Common sleep disorders associated with traumatic brain injury, referred to as TBI, include insomnia, circadian rhythm sleep wake disorder and obstructive sleep apnea. Insomnia is the most common sleep disturbance after concussion.

The new Management of Sleep Disturbances following Acute Concussion/Mild TBI Clinical Recommendations suite is composed of clinical recommendations, a clinical support tool, a provider education slide deck and a patient education fact sheet.

"These clinical recommendations advise that all patients with concussion symptoms should be screened for the presence of a sleep disorder," said U.S. Public Health Service Capt. Cynthia Spells, DVBIC's clinical affairs officer. "Patients should be asked if they are experiencing frequent difficulty in falling or staying asleep, excessive daytime sleepiness or unusual events during sleep. The initial step in the diagnosis of a sleep disorder includes a focused sleep assessment."

Non-pharmacological measures to treat insomnia that focus on stimulus control and good sleep hygiene are the preferred methods of treatment. Short-term use of sleep medication may be necessary in addition to these measures if they are not effective by themselves.

Spells said stimulus control means controlling your environment to help promote sleep. Examples of stimulus control measures include relaxing before bedtime, going to bed only when sleepy, getting out of bed when unable to sleep, removing electronics (TV, smart phone, computer) from the bedroom and using the bedroom only for sleep and intimacy.

Sleep hygiene habits include avoiding caffeine and other stimulants close to bedtime, daily physical activity but not exercising close to bedtime, arising at the same time every morning, getting natural light exposure every day, and avoiding alcohol, nicotine and large meals close to bedtime.

Spells said the new sleep disturbance clinical recommendations and support tool product suite was developed by the Department of Defense in collaboration with the Department of Veterans Affairs and civilian medical professionals.

"Although tailored for the military and VA health care systems, these recommendations may be used by civilian health care providers treating concussion associated sleep disorders," Spells said. "Many service members and veterans, especially those serving in the National Guard and Reserve, receive care from civilian health care specialists." 

DVBIC serves as the Department of Defense subject matter expert on TBI and manager of the TBI pathway of care.
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Study: Concussion can mean depression years later

A study done in mice shows that concussions can lead to the development of depression later in life.

A head injury can lead immune-system brain cells to go on "high alert" and overreact to later immune challenges by becoming excessively inflammatory -- a condition linked with depressive complications, a new animal study suggests.

The findings could help explain some of the midlife mental-health issues suffered by individuals who experience multiple concussions as young adults, researchers say. And these depressive symptoms are likely inflammation-related, which means they may not respond to common antidepressants.

An added complication is that aging already increases brain inflammation. So on top of normal aging concerns, people who have had a traumatic brain injury (TBI) experience added inflammation caused by magnified immune responses to so-called "secondary challenges," such as a second head injury, infections or other stressors.

In mice, these high-alert cells in the brain -- called microglia -- had an exaggerated response to an immune challenge one month after a moderate brain injury. This increased brain inflammation corresponded with the development of depressive behaviors that were not observed in uninjured mice.

"If we had waited three, six or nine months, the symptoms probably would have gotten even worse," said lead author Jonathan Godbout, associate professor of neuroscience at The Ohio State University and a researcher in the Institute for Behavioral Medicine Research.

"A lot of people with a history of head injury don't develop mental-health problems until they're in their 40s, 50s or 60s. That suggests there are other factors involved, and that's why we're looking at this two-hit idea -- the brain injury being the first and then an immune challenge. It's as if one plus one plus one equals 15. There can be a multiplier effect."

The research is published online in the journal Biological Psychiatry.

This work applies to concussive brain injuries that result in a diffuse -- or spread out -- trauma to the brain. These are also concussive injuries from which people and animals recover fairly quickly, typically showing no problems with thinking or moving about a week after the injury to the brain.

In the study, researchers compared uninjured mice with mice that had experienced a moderate TBI. Injured mice showed some initial coordination problems, but those resolved within a week.

The injured mice also showed signs of depressive symptoms that improved within one month. Godbout and colleagues attributed those symptoms to the expected neuroinflammation that occurs after a traumatic brain injury. In these mice, most of the inflammation had cleared within seven days.

Thirty days after injury, researchers examined the brains of the injured mice to determine whether immune cells had remained on high alert since the injury. As expected, the injured brains contained microglia that had stayed in a "primed" state -- meaning they were on standby to respond to a challenge to the immune system. The cells in the brains of uninjured mice did not have the same characteristics.

Under normal circumstances, microglia are the first line of defense and help protect the brain after injury or infection by making proteins and other chemicals that generate just enough inflammation to repair the problem. When they are primed, however, these cells are in a higher state of alert and when they are activated, they generate an amplified immune response that lasts longer than necessary. When these systems are activated with nothing to fight, the circulating chemicals and proteins generate excessive inflammation.

"The young adult mice that have a diffuse head injury basically recover to normal, but not everything is normal. The brain still has a more inflammatory makeup that is permissive to hyperactivation of an immune response," Godbout said.

At 30 days after TBI, the mice were injected with lipopolysaccharide (LPS) -- the dead, outer cell wall of bacteria that stimulates an immune reaction in animals. Tests showed that over the course of 24 hours after the injection, TBI mice were much less social than uninjured mice -- one type of depressive symptom in these animals. The brains of the TBI mice also had dramatically higher levels of two inflammation-related proteins than did brains from normal mice.

Seventy-two hours after the LPS challenge, injured mice showed additional depressive symptoms, including minimal interest in sugar water -- a sign that they avoided what is typically a pleasurable activity. They also showed increased resignation, or a sign of "giving up."

Uninjured mice behaved normally and the levels of inflammatory proteins in their brains had returned to baseline over the same time period.

"These results tell us the TBI mice are having an amplified and prolonged activation of microglia, and that was associated with development of depressive symptoms in the mice," Godbout said.

His lab is now investigating potential treatments that could either prevent the priming of microglia immediately after injury or later reverse the high-alert characteristics of these cells.

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Pain following traumatic brain injury in children

A study on persistent pain in children following traumatic brain injury, such as concussions, showed that children benefit from early interventions.

This is the first study to examine the prevalence of persistent pain over long-term follow-up in adolescents after TBI and its impact on health-related quality of life. These findings indicate that adolescents with TBI may benefit from timely evaluation and intervention to minimize the development and impact of pain.

• Traumatic brain injury (TBI) is a leading cause of pediatric disability. Although persistent pain has been recognized as a significant postinjury complication, there is a paucity of data concerning the postinjury pain experience of youth.
• This study aimed to examine the prevalence of persistent pain in adolescents after TBI, identify risk factors for pain, and evaluate the impact of pain on adolescent health-related quality of life.
• Participants included 144 adolescents with mild to severe TBI who were followed over 36 months after injury. At 3-, 12-, 24-, and 36-month assessments, measures of pain intensity, depression, posttraumatic stress disorder, and health-related quality of life were completed by adolescents.
• Findings demonstrated that 24.3% of adolescents reported persistent pain (defined as usual pain intensity >3/10) at all assessment points after TBI.
• Female sex (odds ratio = 2.73, 95% confidence interval = 1.12–6.63) and higher levels of depressive symptoms at 3 months after injury (odds ratio = 1.26, 95% confidence interval = 1.12–1.43) were predictors of persistent pain at 36 months.
• Furthermore, mixed linear models indicated that early pain experience at 3 months following TBI was associated with a significantly poorer long-term health-related quality of life.

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Concussion protection from helmets: There is no safest football helmet

Regardless of how new or old and expensive or inexpensive a helmet is, they all provide the same level of protection from concussions.

Given the recent controversies over concussions in the NFL, you're probably a little leery about letting your kid play football. We can't blame you. Even future Hall of Famer Kurt Warner told the "Dan Patrick Show" last year that he'd be scared for his sons' safety if they followed their gridiron dreams.

Concussions are a problem for football players, from the pro ranks right on down to pony leaguers. Teenage boys suffer the most sports-related traumatic brain injuries – including concussions – each year, most of which stem from playing football or crashing bicycles. No question: There's risk involved in sending your son out to get pummeled at the 50-yard line, so you want him to sport the best helmet available. Just don't get lured into shelling out big bucks or pressuring his school to buy the latest and greatest helmet. According to a new study, safest does not mean newest, flashiest, or most expensive.

Researchers tracked more than 1,300 high school football players throughout the 2012 season and found that all helmets, regardless of brand, model, or whether they were shiny-new or up to 10 years old, offered the same protection from concussions. Which means that when one brand claims its helmets are safer than the competitors' – or that its spendiest model is the best you can get – it's basically an empty ploy for your pocketbook, says lead researcher Timothy McGuine of the University of Wisconsin Health Sports Medicine Center.

According to McGuine, football helmets are tested and strictly regulated by the National Operating Committee on Standards for Athletic Equipment. To make sure they stay in prime working order, all helmets sold to schools must be serviced by the manufacturer every two years and pitched after 10. The result: "Not one NOCSAE-approved helmet is bad," McGuine says. "They're all hard shells with slightly different padding and fixation systems, but to say one is better than another just isn't true."

Given his findings, McGuine says to rest easy when it comes to helmet quality and your kid's concussion risk. Yes, brain injuries are always possible in contact sports, but he's confident football players' heads are as safe as they can be with today's helmets, regardless of whether they cost $250 or $850.

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Children with ADHD have longer-lasting head injuries

Children who have ADHD may have head injuries that last longer than those without ADHD.

Children with attention-deficit hyperactivity disorder should be steered away from contact sports such as football or basketball because these kids may be at greater risk of long-lasting head injury than their peers, a new study recommends.

Scientists found that children with ADHD -- who are already prone to risk-taking behaviors -- were much more likely than kids without the disorder to suffer a moderate disability after sustaining a mild traumatic brain injury from events such as car accidents, falls and injuries from high-impact sports.

"This was a phenomenon that I had noticed in my own practice -- some children with ADHD didn't recover as well following a traumatic brain injury," said senior study author Dr. Stephanie Greene, an assistant professor of neurological surgery at Children's Hospital of Pittsburgh. Some of the symptoms of traumatic brain injury are also symptoms of ADHD -- disinhibited behavior and impaired memory, she noted. "The effects of the [traumatic brain injury] may be additive to those of ADHD," she explained.

Encouraging activities in which the chances of brain injury are lower -- for example, swimming or track instead of football or basketball -- is a way in which parents can provide an outlet for energy while protecting their child's brain, she added.

The study is published online June 25 in the Journal of Neurosurgery: Pediatrics.

About 8 percent of American children have ADHD, a neurological disorder characterized by problems focusing, being overactive and exhibiting poor impulse control, according to the U.S. Centers for Disease Control and Prevention. Traumatic brain injury results in more than 7,000 deaths, 60,000 hospitalizations and 600,000 emergency room visits annually in the United States, according to the study. Prior research has linked several aspects of ADHD and traumatic brain injury.

In the new study, Greene and her colleagues reviewed medical charts of all patients at Children's Hospital of Pittsburgh who had ADHD and were diagnosed with a mild traumatic brain injury between 2003 and 2010. Forty-eight of these children were compared with a control group of 45 children without ADHD who had also sustained a mild traumatic brain injury.

The researchers found that 25 percent of the ADHD group suffered a moderate disability, and 56 percent had completely recovered after a nearly six-month follow-up period. In contrast, among the patients without ADHD, only 2 percent suffered a moderate disability and 84 percent had completely recovered after a much shorter follow-up of seven weeks. Moderate disability was defined as needing supervision or help for physical or behavioral problems, or having residual problems with learning or functioning.

Dr. Andrew Adesman, chief of developmental and behavioral pediatrics at Steven and Alexandra Cohen Children's Medical Center of New York in New Hyde Park, praised the study's design and said the authors excelled at explaining the possible implications of the findings.

"As someone who specializes in the evaluation and care of children with ADHD, I know they are at increased risk of injury," he said. "I think this study is suggesting that if they do experience a significant head injury, they may have greater long-term problems from that. Why that's true is hard to know."

The study made several recommendations stemming from the results, including that doctors should counsel families of children with ADHD about expected outcomes after a head injury; that more intensive treatment and rehabilitation for these patients be initiated; and that parents perhaps discourage children with ADHD from sports or hobbies that carry higher risks of sustaining a traumatic brain injury.

"Part of the problem with children with ADHD is that they often have poor impulse control, which means that they are at higher risk of sustaining a [traumatic brain injury] by engaging in risk-taking behaviors in daily life, separate from sports," Greene said. "When risky sports are added to the already elevated risk of [traumatic brain injury], the chances of a child sustaining a [traumatic brain injury] with potentially lingering effects become unacceptably high."

But Adesman said the findings need to be replicated before he would agree with curtailing contact sports for children with ADHD.

"I would not steer all kids with ADHD away from contact sports based on single study," he said. "Certainly we know that kids can experience accidents thru a variety of means . . . sports accidents made up a very small percent of accidents" in this study.

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Heading Soccer Balls and Brain Injury

A study shows that heading a soccer ball can result in brain injury resembling a concussion.

Researchers at Albert Einstein College of Medicine of Yeshiva University have shown that soccer players who frequently head the ball have brain abnormalities resembling those found in patients with concussion (mild traumatic brain injury). The study, which used advanced imaging techniques and cognitive tests that assessed memory, published online today in the journalRadiology.

"We studied soccer players because soccer is the world's most popular sport," said Michael L. Lipton, M.D., Ph.D., associate director of Einstein's Gruss Magnetic Resonance Research Center and medical director of MRI services at Montefiore, the University Hospital and academic medical center for Einstein. "Soccer is widely played by people of all ages and there is concern that heading the ball -- a key component of the sport -- might damage the brain." Dr. Lipton is also associate professor of radiology, of psychiatry and behavioral sciences and in the Dominick P. Purpura Department of Neuroscience at Einstein.

On average, soccer players head the ball six to 12 times during games, where balls can travel at speeds of more than 50 miles per hour. During practice drills, players commonly head the ball 30 or more times. The impact from a single heading is unlikely to cause traumatic brain damage such as laceration of nerve fibers. But scientists have worried that cumulative damage from heading's repeated subconcussive impacts might be clinically significant. "Repetitive heading could set off a cascade of responses that leads to degeneration of brain cells over time," noted Dr. Lipton.

To study possible brain injury from heading, the researchers used diffusion tensor imaging (DTI), an advanced MRI-based imaging technique, on 37 amateur adult soccer players (median age 31 years) who had all played the sport since childhood. Participants reported playing soccer for an average of 22 years and had played an average of 10 months over the previous year. Researchers ranked the players based on heading frequency and then compared the DTI brain images of the most frequent headers with those of the remaining players. All participants also underwent cognitive testing.

DTI "sees" the movement of water molecules within and along axons, the nerve fibers that constitute the brain's white matter. This imaging technique allows researchers to measure the uniformity of water movement (called fractional anisotropy, or FA) throughout the brain. Abnormally low FA within white matter indicates axon damage and has previously been associated with cognitive impairment in patients with traumatic brain injury.

"The DTI findings pertaining to the most frequent headers in our study showed white-matter abnormalities similar to what we've seen in patients with concussion," said Dr. Lipton. "Soccer players who headed the ball above a threshold between 885 to 1,550 times a year had significantly lower FA in three areas of the temporal-occipital white matter." Dr. Lipton noted that players with more than 1,800 headings per year were also more likely to demonstrate poorer memory scores compared to participants with fewer yearly headings.

"Our study provides compelling preliminary evidence that brain changes resembling mild traumatic brain injury are associated with frequently heading a soccer ball over many years," said Dr. Lipton. "While further research is clearly needed, our findings suggest that controlling the amount of heading that people do may help prevent brain injury that frequent heading appears to cause."

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