Routine hits playing football cause damage to the brain

August 7, 2019

Science Daily/Carnegie Mellon University

New research led by Carnegie Mellon University and the University of Rochester Medical Center indicates that concussions aren't the sole cause of damage to the brain in contact sports. A study of college football players found that typical hits sustained from playing just one season cause structural changes to the brain.

The researchers studied 38 University of Rochester players, putting accelerometers -- devices that measures accelerative force -- in their helmets for every practice and game. The players' brains were scanned in an MRI machine before and after a season of play.

While only two players suffered clinically diagnosed concussions during the time they were followed in the study, the comparison of the post- and pre-season MRIs showed greater than two-thirds of the players experienced a decrease in the structural integrity of their brain. Specifically, the researchers found reduced white matter integrity in the midbrain after the season compared to before the season. Furthermore, and indicating the injury was specifically related to playing football, the researchers found the amount of white matter damage was correlated with the number of hits to the head players sustained.

The study is published in the journal Science Advances.

 "Public perception is that the big hits are the only ones that matter. It's what people talk about and what we often see being replayed on TV," said senior study author Brad Mahon, an associate professor of psychology at Carnegie Mellon and scientific director of the Program for Translational Brain Mapping at the University of Rochester. "The big hits are definitely bad, but with the focus on the big hits, the public is missing what's likely causing the long-term damage in players' brains. It's not just the concussions. It's everyday hits, too."

The midbrain, located in the center of the head and just beneath the cerebral cortex, is part of a larger stalk-like rigid structure that includes the brain stem and the thalamus. The relative rigidity of the midbrain means it absorbs forces differently than surrounding softer tissues, making it biomechanically susceptible to the forces caused by head hits. The midbrain supports functions like eye movements, which are impacted by concussions and hits to the head. While head hits are known to affect many parts of the brain simultaneously, the researchers decided to focus the study on the midbrain, hypothesizing that this structure would be the "canary in the coal mine" for sub-concussive hits.

"We hypothesized and found that the midbrain is a key structure that can serve as an index of injury in both clinically defined concussions and repetitive head hits," said Adnan Hirad, an M.D./Ph.D. candidate at the University of Rochester's Medical Scientist Training Program and lead author of the study. "What we cataloged in our study are things that can't be observed simply by looking at or behaviorally testing a player, on or off the field. These are 'clinically silent' brain injuries."

Each player in the study received an MRI scan within two weeks of the start of each season and within one week at the end. The helmet accelerometers measured linear and rotational acceleration during all practices and games, recording all contact that produced forces of 10 gs or greater. Astronauts on the space shuttle experienced 3 gs during lift-off. Race car drivers feel the effects of 6 gs, and car crashes can produce brief forces of more than 100 gs.

The 38 NCAA Division III players experienced nearly 20,000 hits across all practices and games. Of those hits, the median force was around 25 gs, with half of the hits exceeding that amount. Only two of the nearly 20,000 hits resulted in concussions.

"We measured the linear acceleration, rotational acceleration and direction of impact of every hit the players sustained. This allowed us to create a three-dimensional map of all of the forces their brains sustained," Hirad said.

The MRI scans measured structural changes in the brain that took place over the course of each season. They found that rotational acceleration (impact causing the head to twist) more so than linear acceleration (head-on impact) is correlated with the observed changes in the structural integrity of white matter in the midbrain.

"This study suggests that midbrain imaging using diffusion MRI might be a way in the future to diagnose injury from a single concussive head hit and/or from repetitive sub-concussive head hits," said Dr. Jeffrey Bazarian, professor of Emergency Medicine, Neurology, Neurosurgery and Public Health Sciences at the University of Rochester Medical Center and a co-author of the study.

The second part of the study served as an independent means to validate the researchers' approach to the football cohort. This group included 29 athletes from various other contact sports who had a clinically defined concussion and 58 who didn't.

The concussed participants underwent MRI scans and offered blood samples within 72 hours of injury. Like the football cohort, those players exhibited reduced structural integrity in the midbrain. In addition, they exhibited increased tau, a protein, in their blood. As structural integrity in the brain decreases, tau increases.

"Tau is an important marker of acute changes in the brain and is thought to be, in the long term, implicated in neurodegenerative diseases like chronic traumatic encephalopathy, also known as CTE," Hirad said.

Given this new insight on repetitive head hits, what should we do?

"Our research, in the context of prior research over the past several years, is beginning to indicate that the accumulation of many sub-concussive hits is instrumental in driving long-term damage in football players' brains," Mahon said. "Future research will be required in order to translate our findings into concrete directives that are relevant to public health. An important direction for future research will be to carry out larger-scale longitudinal studies of contact sports athletes in various ages groups."

"We also need to re-evaluate how we make return-to-play decisions," Hirad said. "Right now, those decisions are made based on whether or not a player is exhibiting symptoms of a concussion like dizziness or loss of consciousness. Even without a concussion, the hits players are taking in practice and games appear to cause brain damage over time."

https://www.sciencedaily.com/releases/2019/08/190807142249.htm

Concussion rates are nearly double what we thought -- and summer is prime injury time

July 2, 2019

Science Daily/University Health Network

A new study has uncovered concussion rates that are nearly double what has previously been recorded, showcasing the need for increased education about concussion and access to more specialized, best-in-practice concussion care.

With concussions seeming more common than ever before, researchers at Toronto Rehabilitation Institute -- University Health Network, set out to answer the question, Are we looking at a true epidemic, or just better recognition?

By embarking on the largest-scale study on concussions ever undertaken in Canada, the researchers discovered that 150,000 of Ontarians (1.2% of province's population) are diagnosed with a concussion each year. That's almost twice as high as previously recorded, and may represent a closer estimate of the true picture of concussion in Ontario.

Their findings were published the Journal of Head Trauma Rehabilitation.

"Past research has looked at the incidence of concussion by examining a particular population; cause of injury; or use a single reporting source, such as records from the Emergency Department. This can under-represent estimates of the real incidence of concussion," says lead author, Laura Langer.

"Our study revealed concussion rates that are almost double what has been previously reported, and highlights the critical importance of looking at everyone who sought medical attention for their concussion."

These more accurate estimates support the importance ongoing awareness around concussion symptoms and management, and the need for more specialized concussion clinics near populations that need them the most.

Video: https://www.youtube.com/watch?v=aJcCd8QINvU&feature=youtu.be

Concussions in Ontario -- who is at risk?

By leveraging the ICES Data Repository -- a province-wide archive that integrates multiple clinical and administrative health databases -- the team captured an unprecedented, comprehensive, view of concussion rates in Ontario between 2008 and 2016.

Here is what they found:

·     About 150,000 Ontarians experience a concussion each year

·     Children under 5 years old experience the highest rate of concussion among all Ontarians

·     Adults over 65 -- especially women -- experience a higher rate of concussion than younger adults

·     26% all of concussions are diagnosed in the summer

·     Rural communities experience a higher rate of concussion than non-rural communities

·     Though most concussions are diagnosed in the Emergency Department, more and more patients with concussion symptoms are visiting their own doctors

Epidemic or better recognition?

According to the team, the high rate of reported concussions is likely influenced by a number of factors, including increased public awareness from athletes and the media, new mandatory reporting laws, and the release of numerous diagnostic and management guidelines for physicians and patients.

Future directions

Access to the ICES Data Repository presents a unique opportunity for Ontario to be a world leader in concussion care and research.

As patients increasingly look to their own doctors for a diagnosis, the researchers identify a need to continue raising awareness about causes and symptoms, and a growing obligation to educate doctors on concussion care.

Furthermore, since about 1 in 7 Ontarians with a concussion will experience persistent, post-concussive symptoms, it's critical to develop tools to identify who will face long-term problems, so we can individualize early treatments to prevent long-term complications.

The study was funded by, and conducted in collaboration with, Ontario Neurotrauma Foundation. Toronto Rehabilitation Institute is also financially supported by the Toronto Rehab Foundation.

This study made use of de-identified data from the ICES Data Repository, which is managed by ICES, a non-profit research institute that uses population-based health information to produce knowledge on a broad range of health care issues.

https://www.sciencedaily.com/releases/2019/07/190702152800.htm

Impact of repetitive heading in soccer needs more research, say experts

February 10, 2014

Science Daily/St. Michael's Hospital

Soccer is the most-popular and fastest-growing sport in the world and, like many contact sports, players are at risk of suffering concussions from collisions on the field.

But researchers warned in a paper published today that not enough attention has been given to the unique aspect of soccer -- the purposeful use of the head to control the ball -- and the long-term consequences of repetitive heading.

The literature review by Dr. Tom Schweizer, director of the Neuroscience Research Program of St. Michael's Hospital, was published in the journal Brain Injury.

More than 265 million people play soccer worldwide, including 27 million in North America. Due to the nature of the sport, players are particularly vulnerable to head and neck injuries. Most are caused by unintentional or unexpected contact, such as when a player collides with teammates, opponents or the playing surface.

There is significant concern in the sporting and medical worlds about the potential long-term cognitive and behavioral consequences for athletes who suffer acute or repeat concussions or multiple "sub-concussive" head impacts -- blows to the head not causing symptoms of concussions.

"The practice of heading, which might occur thousands of times over a player's career, carries unknown risks, but may uniquely contribute to cognitive decline or impairment in the short- or long-term," said Dr. Schweizer, a neuroscientist. "Thus, soccer players present a unique opportunity to study whether cumulative sub-concussive impacts affect cognitive functioning, similar to that of concussions."

Examining research papers that studied the incidence of concussion in soccer, he found that concussions accounted for 5.8 per cent to 8.6 per cent of total injuries sustained during games. One study found that 62.7 per cent of varsity soccer players had suffered symptoms of a concussion during their playing careers, yet only 19.2 per cent realized it. Another found that 81.8 per cent of athletes who had suffered a concussion had experienced two or more and that players with a history of concussion had a 3.15 times greater odds of sustaining another one than those who had never had a concussion. One study found concussions sustained during soccer accounted for 15 per cent of the total number of concussions in all sports. In particular, girls' soccer accounted for 8.2 per cent of sports-related concussions, the second highest sport after football.

Research papers that looked at the mechanism of injury found 41.1 per cent of concussions resulted from contact by an elbow, arm or hand to the head. One found that 58.3 per cent of concussions occurred during a heading duel. More females suffered concussions from player-to-surface and player-to-ball contact than males who had more player-to-player contact than females.

Defensemen and goalkeepers are at greatest risk of suffering a concussion, the study found. Dr. Schweizer said that for goalkeepers, the risk decreases as they get older and become more aware of where they are at any given time in relation to the goal posts. He said padding goal posts might be one way to reduce concussions in younger players who don't have such a developed sense of spatial relations.

Studies on the long-term effects of heading found greater memory, planning and perceptual deficits in forwards and defenders, players who execute more headers. One study found professional players reporting the highest prevalence of heading during their careers did poorest in tests of verbal and visual memory as well as attention. Another found older or retired soccer players were significantly impaired in conceptual thinking, reaction time and concentration. The few studies that used advanced imaging techniques found physical changes to the brains in players who had concussions.

Monica Maher, a co-author and University of Toronto master's degree student in neuroscience, said the researchers wanted to emphasize possible injury prevention methods.

"Use of protective headgear, limiting heading exposure or stressing proper heading technique in younger children and increasing concussion education are all suggestions to perhaps decrease the incidence of head injury and their subsequent effects in the long run," she said.

http://www.sciencedaily.com/releases/2014/02/140210114538.htm

Antioxidant therapy may have promising potential in concussion treatment

April 1, 2015

Federation of American Societies for Experimental Biology (FASEB)

Antioxidants may play a key role in reducing the long-term effects of concussions and could potentially offer a unique new approach for treatment, a new study suggests. Common among athletes and soldiers, it is estimated that 3.4 million concussions occur each year in the United States. The development of a readily available oral supplement would have the potential to improve brain function in a percentage of concussion sufferers.

Common among athletes and soldiers, it is estimated that 3.4 million concussions occur each year in the United States. The development of a readily available oral supplement would have the potential to improve brain function in a percentage of concussion sufferers.

The study adds to recent findings that concussions can lead to chronic traumatic encephalopathy. Head injuries often lead to chronic traumatic encephalopathy, a disease associated with long-term brain damage and behavioral symptoms including memory loss, impulsive behavior, depression and aggression. The number of retired athletes and veterans diagnosed with chronic traumatic encephalopathy has climbed in recent years.

"Concussions can contribute to long-term changes within the brain and these changes are the result of cell death, which may be caused by oxidative stress," said Brandon Lucke-Wold, a M.D./Ph.D. student at West Virginia University's Medical School who conducted the research. "This study shows that antioxidants such as lipoic acid can reduce the long-term deficits when given after a concussion."

In Lucke-Wold's research, rats were divided into three groups: a non-concussed control group, a group that experienced concussive injury and another concussed group that received lipoic acid supplementation. Seven days after the concussion, the rats were tested for seemingly impulsive behavior through an elevated maze. The rats exposed to concussion without lipoic acid had increased impulsive behavior, and spent more time exploring open spaces indicative of risk taking behavior.

"This increase in impulsive behavior was an indication of underlying brain damage," said Lucke-Wold, who will present the research at the American Society for Pharmacology and Experimental Therapeutics (ASPET) Annual Meeting during Experimental Biology 2015.

Analysis of brains of the group receiving supplementation showed markedly decreased impulsive behavior. "These findings make sense because lipoic acid works to help reduce toxic free radicals that can damage cells," said Lucke-Wold.

"By understanding the mechanisms behind brain injury following concussion, we can more effectively target treatment interventions to reduce these damaging effects," he added.

http://www.sciencedaily.com/releases/2015/04/150401132752.htm