Researchers probe the complex nature of concussion

March 31, 2018 by Nathan Collins, Stanford University
Researchers probe the complex nature of concussion
David Camarillo and colleagues used computer simulations and data collected from football gear to study the complex nature of concussion. Credit: Saul Bromberger and Sandra Hoover

It seems simple enough: Taking a hard hit to the head can give you a concussion. But, Stanford researchers report March 30 in Physical Review Letters, in most cases, the connection is anything but simple.

Combining data recorded from with computer simulations of the brain, a team working with David Camarillo, an assistant professor of bioengineering, found that concussions and other mild traumatic brain injuries seem to arise when an area deep inside the brain shakes more rapidly and intensely than surrounding areas. But, they also found that the mechanical complexity of the brain means there is no straightforward relationship between different bumps, spins and blows to the head and the likelihood of injury.

"Concussion is a silent epidemic that is affecting millions of people," said Mehmet Kurt, a former in Camarillo's lab. Kurt and Kaveh Laksari, also a former postdoctoral fellow with Camarillo, are co-lead authors on the paper. Yet exactly how concussions come about remains something of a mystery. "What we were trying to do is understand the biomechanics of the brain during an impact." Armed with that understanding, Kurt said, engineers could better diagnose, treat and hopefully prevent concussion.

Shaking the brain

In previous studies, Camarillo's lab had outfitted 31 with special mouthguards that recorded how players' heads moved after an impact, including a few cases in which players suffered concussions.

Laksari and Kurt's idea was to use that data, along with similar data from NFL players, as inputs to a computer model of the brain. That way, they could try to infer what happened in the brain that led to a . In particular, they could go beyond relatively simple models that focused on just one or two parameters, such as the maximum head acceleration during an impact.

The key difference between impacts that led to concussions and those that did not, the researchers discovered, had to do with how - and more importantly where - the brain shakes. After an average hit, the researchers' computer model suggests the brain shakes back and forth around 30 times a second in a fairly uniform way; that is, most parts of the brain move in unison.

In injury cases, the brain's motion is more complex. Instead of the brain moving largely in unison, an area deep in the brain called the ­- which connects the left and right halves of the brain - shakes more rapidly than the surrounding areas, placing significant strain on those tissues.

Further complications

Concussion simulations that point to the corpus callosum are consistent with empirical observations - patients with concussions do often have damage in the corpus callosum. However, Laksari and Kurt emphasize that their findings are predictions that need to be tested more extensively in the lab, either with animal brains or human brains that have been donated for scientific study. "Observing this in experiments is going to be very challenging, but that would be an important next step," Laksari said.

Perhaps as important as physical experiments are additional simulations to clarify the relationship between head impacts and the motion of the brain - in particular, what kinds of impacts give rise to the complex motion that appears to be responsible for concussions and other mild traumatic brain injuries. Based on the studies they have done so far, Laksari said, they know only that the relationship is highly complex.

Still, the payoff to uncovering that relationship could be enormous. If scientists better understand how the moves after an and what movement causes the most damage, Kurt said, "we can design better helmets, we can devise technologies that can do onsite diagnostics, for example in football, and potentially make sideline decisions in real time," all of which could improve outcomes for those who take a nasty hit to the .

Explore further: Brain protein changes could explain how concussions affect patients

More information: Kaveh Laksari et al, Mechanistic Insights into Human Brain Impact Dynamics through Modal Analysis, Physical Review Letters (2018). DOI: 10.1103/PhysRevLett.120.138101

Related Stories

New studies show brain impact of youth football

November 27, 2017

School-age football players with a history of concussion and high impact exposure undergo brain changes after one season of play, according to two new studies conducted at UT Southwestern Medical Center in Dallas and Wake ...

Zebrafish brain repair following concussion

January 2, 2018

A simple and inexpensive zebrafish model of concussion, reported in eNeuro, reveals the genetic pathways underlying the animal's remarkable ability to regenerate injured brain tissue. Understanding the mechanisms of regeneration ...

Recommended for you

En route to the optical nuclear clock

April 18, 2018

The nucleus of thorium-229 possesses a property that is unique among all known nuclides: It should be possible to excite it with ultraviolet light. To date, little has been known about the low-energy state of the Th-229 nucleus ...

When nuclei catch up with electrons

April 17, 2018

In an attosecond study of the H2 molecule, physicists at ETH Zurich found that for light atomic nuclei, as contained in most organic and biological molecules, the correlation between electronic and nuclear motions cannot ...

Researchers create new Bose-Einstein condensate

April 17, 2018

Researchers at Aalto University, Finland, have created a Bose-Einstein condensate of light coupled with metal electrons, so-called surface plasmon polaritons. Nearly 100 years ago, Albert Einstein and Satyendra Nath Bose ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.