Turning Up the Volume on a Silent Epidemic: Advanced Imaging & TBI

 
 
 
 - TBI: Athlete with iPad
Source: University of Notre Dame
 

Through the 17 weeks of the National Football League 2012 regular season and four weeks of playoffs, there were 170 reported concussions, according to a collaborative effort to track the injuries conducted by PBS’ Frontline and ESPN. Attention to head injuries in sports has spiked—indeed, such a comprehensive list of NFL concussions would have appeared nowhere in the mainstream media five years ago. The sea change is due in part to increasing reports of long-term repercussions from the injury in athletes and military veterans, but also because medical imaging is revealing more about this previously silent epidemic.

Concussions, or mild traumatic brain injuries (mTBI), differ from severe TBI based on severity—mTBI results in brief changes in mental state or consciousness, while severe TBI can lead to extended periods of unconsciousness and amnesia. Despite the distinction in initial severity, more evidence is indicating that long-term cognitive deficits can be experienced even with mTBI. Each year, there are at least 1.7 million TBIs in the U.S., with concussions making up about 75 percent, according to the Centers for Disease Control and Prevention.

At the launch of the Concussion Center at NYU Langone Medical Center in New York City in March, Steven L. Galetta, MD, chair of the department of neurology at NYU Langone Medical Center, explained that only 15 percent of people who suffer concussions actually seek treatment. There has been a doubling of the concussion rate over the last decade due to increased recognition of the condition, but more research is needed.

Take one tablet & call me in the morning

While imaging is playing in a huge role in the study of mTBI, researchers at the University of Notre Dame in South Bend, Ind., are working on an imaging-free method of identifying concussions in athletes using a tablet-based testing system.

The system works by having athletes speak into an iPad tablet to establish a baseline reading of a person before a potentially concussion-inducing sporting event. A second sample is taken after the event, and the system looks for traumatic brain injury indicators, such as distorted vowels, hyper nasality and imprecise consonants.

Nine concussions were confirmed out of 125 student participants in a 2012 campus boxing tournament using the technique, according to a Notre Dame press release. Another set of tests conducted during the 2013 boxing tournament is currently being evaluated.

“We need better biomarkers, better imaging predictors of who’s at greater risk,” says Galetta. In the past, a person who hit his or her head or an athlete who had his or her “bell rung” might have been given smelling salts and then sent on his or her way, but Galetta says we are in the beginning stages of a major shift in how concussion will be approached in the future, with advanced imaging playing a key role in the process.

Shifting opinions

The tipping point in this change of attitudes actually came before concussions in sports were thrust into the spotlight. Soldiers returning from Afghanistan and Iraq were exhibiting signs of neurological deficits, despite normal brain appearance on CT imaging, leading to a desire to learn more about the characteristics of brain injury, says Rao P. Gullapalli, PhD, of the University of Maryland School of Medicine in Baltimore.

“I think public awareness has increased and, unfortunately, it had to be the wars and these football players, because this problem has been there all along,” says Gullapalli. “It just did not get attention because people lived with these symptoms.”

While soldiers and athletes brought the issue to the popular media, within the field of neuroradiology, advanced MRI techniques like diffusion tensor imaging (DTI) showed brain injuries could exist even when conventional imaging showed nothing wrong structurally.

“[DTI] sort of opened our eyes to say ‘Oh my goodness, there is something going on in here indeed and this was probably the cause of their long-term outcomes,’” says Gullapalli. No two concussions are the same, he adds, but research into the subtle changes connected to post-concussive symptoms has demonstrated the importance of looking at the midbrain and thalamus. Nerve fibers project out to the cortex from the thalamus and any disruption on the cortex can translate to communication breakdowns within these fibers.

The ability to analyze function as opposed to just structure is key to understanding brain injuries, according to Richard D.