Stanford to study head trauma through high-tech mouth guards

ATHERTON, Calif. — For spectators, Menlo School’s rough-and-tumble football games are as traditional as autumn leaves, apple cider and crisp air.

But the young athletes are wearing something high-tech and hidden: custom-designed mouth guards with motion sensors, collecting data that reveals what happens to the brain in the moments after a hit.

The new Stanford research project is the nation’s first study in youth to measure rotation and full motion of the head during impacts, according to co-principal investigator and concussion expert David Camarillo, assistant professor of bioengineering.

While his team previously has studied concussion in Stanford athletes and National Football League players, they sought to learn more about the consequences in the developing brain. An estimated 4 million teenagers and children play the sport, raising concerns about long-term cognitive impact.

“It’s important to expand our research to the high school level and younger,” he said, “because that’s where there are the most athletes.”

About 100 football players in three private schools — Menlo School and Sacred Heart Preparatory in Atherton and Archbishop Mitty High School in San Jose — are volunteers in the first year of the study, which will continue through the 2018 football season. It aims to expand to more schools in 2019.

The players’ special mouth guards look like conventional mouth guards, only a little bit bigger. Patriotically molded from red, white and blue plastic, they’re custom-designed to fit each player’s mouth so they’re more comfortable than conventional mouth guards.

Embedded in the front, next to the incisor teeth, are gyroscopic sensors and accelerometers that measure the mouth guard’s position in space, as well as the forces that are acting upon it. In essence, it documents how the head is moving.

It records any acceleration of 10 g forces, a frequent occurrence in adult players. (By comparison, space shuttle astronauts experience a maximum of 3 g forces on launch and re-entry.) Then it wirelessly sends this data, via Bluetooth, for storage and analysis.

“There are no buttons, no wires,” said Will Mehring, a clinical research assistant for the study, who works with the volunteer players on the fields.

Videos of games and practices can match the player’s time-stamped data to each impact. The mouth guard measures the force; the video shows what caused it.

They hope to learn what impacts are most damaging and which positions are most vulnerable, said Mehring. They can even study “sub-concussive” impacts that aren’t recognized but are still potentially dangerous.

Using this information, “you can advise players to change their habits,” Mehring said. “Or you can tell coaches: ‘You know, this specific practice in this drill — we saw that we had a very high number of impacts. So maybe you could consider training that skill or doing that drill in a different way, to make it safer for the players.’ ”

Helping carry and set up the electronic equipment on the field’s sidelines, research assistant and Menlo junior Sam Weseloh, 16, welcomed the research. He suffered three concussions while playing football and has been advised by his doctor to stick to his other passion, baseball. But he still loves football, and many of his friends still play.

“The more research we can get on what it means to have concussion symptoms, that can really impact lives, and change them,” said Weseloh, who is looking forward to a career in medicine.

“A lot of kids play through injuries,” he said. “I know how concussion personally affects you as a teenager — you miss a lot of school.”

The debilitating effects of repeated concussions on football players have been well documented. The trauma is linked to Chronic Traumatic Encephalopathy, a progressive neurodegenerative brain disease. It’s incurable, with symptoms that include blurred vision, dementia, depression, headaches, memory loss and mood swings.

What scientists still don’t clearly know is whether those injuries are the result of thousands of tiny impacts or singular, crushing blows to the brain, and the nature of the impacts that cause them.

The mechanical complexity of the brain means there is no direct relationship between a blow to the head and the likelihood of injury, according to Camarillo’s earlier work. Using computer modeling, they found that the key difference between impacts that led to concussions and those that did not has to do with how — and more importantly where — the brain shakes.

After a noninjurious hit, their research suggests the brain shakes back and forth around 30 times a second in a fairly uniform way, with most parts of the brain moving in unison. In injury cases, the brain’s motion is more complex: an area deep in the brain called the corpus callosum, which connects the left and right halves of the brain, shakes more rapidly than the surrounding areas, placing significant strain on those tissues.

A force to the side of the head, making it move from side to side or rotate, is more likely to produce a concussion than a blow that moves it back and forward, according to work by Dr. Jamshid Ghajar, a neurosurgeon at the Stanford Concussion and Brain Performance Center.

Camarillo’s team is specifically interested in what type of blows damage the brain’s wiring — those long threadlike parts of the nervous system, called axons, which carry signals.

The funding for the research comes from a $14.5 million donation by the Taube family to fund research at Stanford on concussions.

“This could potentially help some of my friends,” Weseloh said. “We could step in, based on a reading from the sensors, before they go back out in the field and damage themselves further.”