Engineer helping unravel mystery of traumatic brain injury

The American Academy of Neurology issued new guidelines last week for assessing school-aged athletes with head injuries on the field. The message: if in doubt, sit out.

With more than 3 million sports-related concussions occurring in the U.S. each year, from school children to professional athletes, the issue is a burgeoning health crisis.

While concussions may not be difficult to diagnose initially, the longer one waits, the more difficult treatment can be.

The efforts of a researcher and his colleagues at Washington University in St. Louis’ School of Engineering & Applied Science are helping to unravel the many mysteries of traumatic brain injury.

“There’s and urgent need to understand the problem of traumatic brain injuries, for the sake of athletes, military personnel and accident victims,” says Philip Bayly, PhD, the Lilyan and E. Lisle Hughes Professor of Mechanical Engineering.

“Anyone who has met someone who’s had a head injury knows how scary it is, and how frustrating it is that we know so little about the causal pathways, and thus the best therapeutic opportunities,” he says.

Bayly, chair of the Department of Mechanical Engineering & Materials Science, researches the mechanics of brain injury. He recently received a $2.25 million grant from the National Institutes of Health to better understand traumatic brain injuries.

Head injuries, concussions and the resulting trauma have been in public discussion recently as the National Football League (NFL) deals with a lawsuit regarding head injuries by about one-third of living former NFL players. The league is accused of not providing information connecting football-related head injuries to brain damage, memory loss and other long-term health issues.

Bayly’s team is working on ways to measure 3-D relative motion between in the brain and skull and estimate strain during mild head acceleration. Bayly hopes computer simulation can teach researchers about the basic physics of brain injury and ways to develop new approaches to prevention and therapy.

“Our studies provide experimental data on how the brain actually responds mechanically in response to mild external loads,” Bayly says. “This is especially critical to developing useful computer simulations, to make sure they reflect reality.
These simulations will in turn be used to design new equipment, evaluate rule changes in sports and determine exposure thresholds or diagnostic tests.”

Computer simulation is important in creating animal models that can be used to develop diagnostic and therapeutic approaches, he says.

“Understanding mechanical deformation in traumatic brain injury is also essential to anyone studying brain trauma by exposing cultured brain cells to mechanical stress,” Bayly says. “We need to understand how much stress to apply and in what directions.”

How can athletes minimize their risks?

“From a mechanical standpoint, they should avoid repeated high head accelerations,” Bayly says. “Head-to-head collisions and collisions with head-to-ground are clearly to be avoided.”

Bayly says to truly protect athletes, new rules need to be instated.

“I would actually advocate for eliminating sports like boxing, in which injury-level accelerations are known to occur routinely. More research is needed on sports where the threshold is less clear.”

There is where Bayly and his colleagues come in.

“We need to do the research to find out what kinds of repeated accelerations are responsible for producing the degeneration seen in chronic traumatic encephalopathy,” he says.

(Image: Jupiterimages / Getty Images)

Second impact syndrome: A devastating injury to the young brain

Physicians at Indiana University School of Medicine and the Northwest Radiology Network (Indianapolis, Indiana) report the case of a 17-year-old high school football player with second impact syndrome (SIS). A rare and devastating traumatic brain injury, SIS occurs when a person, most often a teenager, sustains a second head injury before recovery from an earlier head injury is complete. To the best of the authors’ knowledge, this is the first reported case in which imaging studies were performed after both injuries, adding new knowledge of the event. Findings in this case are reported and discussed in “Second impact syndrome in football: new imaging and insights into a rare and devastating condition. Case report,” by Elizabeth Weinstein, M.D., and colleagues, published today online, ahead of print, in the Journal of Neurosurgery: Pediatrics.

MRIs Reveal Signs of Brain Injuries Not Seen in CT Scans

Hospital MRIs may be better at predicting long-term outcomes for people with mild traumatic brain injuries than CT scans, the standard technique for evaluating such injuries in the emergency room, according to a clinical trial led by researchers at UCSF and the San Francisco General Hospital and Trauma Center (SFGH).

Published this month in the journal Annals of Neurology, the study led by UCSF neuroradiologist Esther Yuh, MD, PhD, followed 135 people treated for mild traumatic brain injuries over the past two years at one of three urban hospitals with level-one trauma centers: SFGH, the University of Pittsburgh Medical Center and University Medical Center Brackenridge in Austin, Texas. The study was called the NIH-funded TRACK-TBI (Transforming Research and Clinical Knowledge in Traumatic Brain Injury).

All 135 patients with mild traumatic brain injuries received CT scans when they were first admitted, and all were given MRIs about a week later. Most of them (99) had no detectable signs of injury on a CT scan, but more than a quarter (27/99) who had a “normal” CT scans also had detectable spots on their MRI scans called “focal lesions,” which are signs of microscopic bleeding in the brain.

Spotting these focal lesions helped the doctors predict whether the patients were likely to suffer persistent neurological problems. About 15 percent of people who have mild traumatic brain injuries do suffer long-term neurological consequences, but doctors currently have no definitive way of predicting whether any one patient will or not.

“This work raises questions of how we’re currently managing patients via CT scan,” said the study’s senior author Geoff Manley, MD, PhD, the chief of neurosurgery at SFGH and vice-chair of the Department of Neurological Surgery at UCSF. “Having a normal CT scan doesn’t, in fact, say you’re normal,” he added.

Better Precision Tools Needed for Head Injuries

At least 1.7 million Americans seek medical attention every year for acute head injuries, and three-quarters of them have mild traumatic brain injuries – which generally do not involve skull fractures, comas or severe bleeding in the brain but have a variety of more mild symptoms, such as temporary loss of consciousness, vomiting or amnesia.

The U.S. Centers for Disease Control and Prevention estimates that far more mild traumatic brain injuries may occur each year in the United States but the true number is unknown because only injuries severe enough to bring someone to an emergency room are counted.

Most of those who do show up at emergency rooms are treated and released without being admitted to the hospital. In general, most people with mild traumatic brain injuries recover fully, but about one in six go on to develop persistent, sometimes permanent, disability.

The problem, Manley said, is that there is no way to tell which patients are going to have the poor long-term outcomes. Some socioeconomic indicators can help predict prolonged disability, but until now there were no proven imaging features, or blood tests for predicting how well or how fast a patient will recover. Nor is there a consensus on how to treat mild traumatic brain injuries.

“The treatment’s all over the place – if you’re getting treatment at all,” Manley said.

The new work is an important step toward defining a more quantitative way of assessing patients with mild traumatic brain injuries and developing more precision medical tools to detect, monitor and treat them, he added.

If doctors knew which patients were at risk of greater disabilities, they could be followed more closely. Being able to identify patients at risk of long-term consequences would also speed the development of new therapeutics because it would allow doctors to identify patients who would benefit the most from treatment and improve their ability to test potential new drugs in clinical trials.