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Publish date: Nov 14, 2011

Rochester study suggests concussive effects of cumulative hits 

By Brian Hendrickson

The discovery happened almost by accident, but the implications of Jeff Bazarian’s concussion study with the University of Rochester football team could alter common perceptions of the injury.

It started with a minor experiment. Jianhui Zhong, a professor of imaging sciences and physics, was introducing Bazarian to a “Diffusion Tensor Imaging” exam. The technology has been around for decades but has recently gained popularity for its ability to study sensitive biological systems more closely. Bazarian, an associate professor of emergency medicine at the University of Rochester Medical Center, was curious about how the DTI could help with the study of concussions.

So, with help from a local high school football team, the two scientists studied scans of 10 players before and after their seasons. They assumed the research would prove fruitless when only one studied player experienced a concussion.

Instead, it produced a eureka moment.

The scans of the injured player showed as much damage as his teammates who endured routine levels of contact, suggesting to Bazarian and Zhong that extreme hits that made athletes’ vision foggy and eyes starry – telltale signs of concussions – weren’t necessary to cause damage to their brains. Instead, it suggested the hits players endured play-to-play and week-to-week could accumulate and affect the brain’s health. Imagine linemen colliding after each snap, a running back getting bumped while powering through a hole, or linebackers finishing off a play. Those plays – the bedrock of game action – could be adversely affecting a player’s health over time, the results suggested.

Those findings, which will soon be published in the medical journal Magnetic Resonance Imaging and support similar findings in concussion studies performed at Purdue and the Cleveland Clinic, could impact the sport at a fundamental level. Everything from helmet designs to player time management to rules changes could be reevaluated.

“We didn’t anticipate that blows to the head that didn’t cause a concussion could cause abnormalities on the scan,” Bazarian said. “We started to think about this and we started to wonder if this was the type of injury that year-after-year could contribute to the traumatic encephalopathy that affected retired NFL players.”

Traumatic encephalopathy, a degenerative brain condition, has made headlines recently as a suspected long-term affect of concussions. Some believe it’s so serious that it could cause depression and, in the case of former Chicago Bears star Dave Duerson, potentially suicidal behavior. Bazarian sought and received one of 16 grants provided by the NFL to continue his research, this time with the University of Rochester football team. Bazarian’s grant was part of the $1.6 million NFL Charities awarded for research in 2011, 62 percent of which was directed to the study of concussions.

The funding helped Bazarian outfit 10 of Rochester’s players with special helmets designed by Riddell, which are outfitted with sensors to measure each hit a player receives. Called “accelerometers,” the sensors can detect the amount of direct force the impact delivers, and how much it causes the helmet to rotate.

Each player underwent a DTI scan before the 2011 season began, and will receive a second scan when the season ends. A cousin of the more commonly known MRI (magnetic resonance imaging), the DTI uses magnetism to measure the movement of water molecules through the body’s tissues, including brain cells called neurons. This provides a more detailed view of sensitive systems. The scan can show researchers each spaghetti-strand of neurons in the brain, and whether the damage from a hit has caused them to swell and stop working. By combining the DTI scan with the data from the accelerometers, Bazarian and Zhong can determine whether the number of collisions matches the degree of brain injury.

The data won’t yield usable information until after the season, and even that data will be too preliminary to cast judgments toward the safety and treatment of players. But Jeffrey Anderson, director of sports medicine for the University of Connecticut and chair of the NCAA’s Committee on Competitive Safeguards and Medical Aspects of Sports, said the information gained will still be important to helping researchers more completely understand the brain and its potential for injury.

“It’s hard to say no one should play football because something has been found,” Anderson said. “It’s hard to make that big a leap. … With all the work that’s been done, we’ve still got preliminary information. There’s still so much we don’t know. Anything that we get has become very valuable.”

For now, the data have provided daily bragging rights for players, who lightheartedly boast about the number of hits their helmets record after each practice. But some day Rochester coach Scott Greene said those hit counts could be used for safety, as well. If the study shows that those routine contacts can adversely affect a player’s health – something that was never suggested when Greene played at Michigan State and for four years in the NFL – those hit counts could direct medical staff to players who need extra rest or treatment.

“You look at the linemen, nobody thinks about the helmet-to-helmet blows,” Greene said. “But the helmet-to-helmet hits obviously build up over a season. We’re talking about the safety to people who play this sport. There’s a lot of different applications that this research can be used for.”

But the research is still far removed from any practical application. While Bazarian and Zhong are ready to publish their initial findings from the high school team, they still must replicate those results. That means finding similar patterns from scans at the end of this season, and seeing other researchers successfully duplicate their study.

They are also interested in testing the common practice of resting players to see if the patterns of damage they discovered will heal after an extended period of inactivity. To do that, players in the study group agreed to abstain from contact sports for six months after the season ends. At that point, a third DTI scan will be conducted to compare with the previous exams to check for signs of healing.

The three phases mean the study won’t begin to yield overall results until the end of next year. At that point, Bazarian and Zhong may know whether their accidental discovery could alter the understanding of concussions.

“At the end of the day, I think we’re just trying to avoid dementia from happening down the line,” Bazarian said. “I have three kids. I don’t want them getting hurt and having brain injury from something they love to do.”