Sinister shock: Researcher studies how explosive shock waves harm the brain

February 23, 2016, Office of Naval Research
Dr. Michael Cho in his lab at the University of Texas at Arlington. With support from the Office of Naval Research, Cho is conducting research to better understand how explosive shock waves harm the brain and contribute to traumatic brain injury. Credit: Dr. Michael Cho

Today's warfighters are outfitted with body armor strong enough to withstand shrapnel from a bomb or other explosive device. One debilitating threat from a blast, however, is a force they can't see—the explosive shock wave itself.

"Shock waves travel faster than the speed of sound," said Dr. Timothy Bentley, a program manager in the Office of Naval Research's (ONR) Warfighter Performance Department. "Warfighters physically well protected from shrapnel aren't protected from . This wave of energy can cause subtle yet damaging effects on the brain."

To better understand how shock waves harm the brain and contribute to , ONR is supporting work by Dr. Michael Cho, chairman of the Bioengineering Department at the University of Texas at Arlington.

Cho's efforts center on the idea that explosive shock waves cause microcavitations, or , to form and collapse in the brain. These energy-packed bubbles are so miniscule (less than a millimeter across) and appear, pop and disappear so quickly that they can't be detected by MRIs or other brain-imaging technology. Consequently, this kind of injury often goes untreated.

When brain microcavitations collapse, they can potentially damage surrounding cells and tissue, Cho said. He theorizes this collapse also compromises and causes leakage through the blood-brain barrier—a tightly packed network of blood vessels in the brain that allows healthy molecules to enter the brain from the bloodstream and prevents the entry of harmful ones.

Symptoms of this type of brain injury can include memory loss, headaches and even .

"We know the symptoms are there," said Cho, "but they're not being addressed because we don't know the cause. If we can see that the blood-brain barrier is damaged, we can perhaps begin contemplating clinical strategies to treat the cause."

To accomplish this, Cho and his research team—working in partnership with Old Dominion University and Purdue University—have created tissue-based models mirroring the properties of tissue and fluids found in the brain and blood-brain barrier. They then use electrical charges to produce shock waves within the models, which are grown on petri dishes.

"Through this method, we can create microbubbles and compare their effects in real time," said Cho. "We can see the formation of tiny bubbles, watch the interaction with the model and determine what kind of damage or leakage might occur."

Future research also will involve developing computer algorithms and simulations to accurately predict what areas of the brain are most susceptible to microcavitation damage.

"Instead of scanning the whole brain for an injury, doctors could focus on specific areas most likely to be injured," said Cho. "They still won't be able to see the microcavitations, but they can look for localized biomarkers indicating their presence—proteins, chemical compounds and blood particles, for example."

In addition to offering a way to treat the thousands of warfighters who have returned from Iraq and Afghanistan with traumatic injuries, Bentley said Cho's research also can potentially help civilians suffering from trauma related to car accidents and contact sports.

Explore further: Engineers use 'shock tube' to find greater impacts of blast waves on brains

Related Stories

Engineers use 'shock tube' to find greater impacts of blast waves on brains

June 9, 2015
By accounting for a rush of blood to the head, University of Nebraska-Lincoln engineers have found that blast waves from concussive explosions may put far greater strain on the brain than previously thought.

Researchers provide first evidence of how obstructive sleep apnea damages the brain

September 1, 2015
UCLA researchers have reported the first evidence that obstructive sleep apnea contributes to a breakdown of the blood–brain barrier, which plays an important role in protecting brain tissue.

Study proves shock wave from explosives causes significant eye damage

June 30, 2014
Researchers at The University of Texas at San Antonio (UTSA) are discovering that the current protective eyewear used by our U.S. armed forces might not be adequate to protect soldiers exposed to explosive blasts.

Even mild traumatic brain injury may cause brain damage

July 16, 2014
Even mild traumatic brain injury may cause brain damage and thinking and memory problems, according to a study published in the July 16, 2014, online issue of Neurology, the medical journal of the American Academy of Neurology.

Recommended for you

A dual-therapy approach to boost motor recovery after a stroke

June 20, 2018
Paralysis of an arm and/or leg is one of the most common effects of a stroke. But thanks to research carried out by scientists at the Defitech Foundation Chair in Brain-Machine Interface and collaborators, stroke victims ...

Absence epilepsy—when the brain is like 'an orchestra without a conductor'

June 20, 2018
At first, the teacher described her six-year-old student as absentminded, a daydreamer. The boy was having difficulty paying attention in class. As the teacher watched the boy closely, she realized that he was not daydreaming. ...

Researchers investigate changes in white matter in mice exposed to low-frequency brain stimulation

June 19, 2018
A team of researchers at the University of Oregon has learned more about the mechanism involved in mouse brain white matter changes as it responds to stimulation. In their paper published in Proceedings of the National Academy ...

Cell type and environment influence protein turnover in the brain

June 19, 2018
Scientists have revealed that protein molecules in the brain are broken down and replaced at different rates, depending on where in the brain they are.

Left, right and center: mapping emotion in the brain

June 19, 2018
According to a radical new model of emotion in the brain, a current treatment for the most common mental health problems could be ineffective or even detrimental to about 50 percent of the population.

Often overlooked glial cell is key to learning and memory

June 18, 2018
Glial cells surround neurons and provide support—not unlike hospital staff and nurses supporting doctors to keep operations running smoothly. These often-overlooked cells, which include oligodendrocytes and astrocytes, ...

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.