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Biomedicine

A Test to Spot Concussions in Athletes

Scientists are developing new technologies to assess when it’s safe for players to return to action.

Concussion is a major problem in athletics: at least 300,000 sports-related concussions occur annually in the United States, according to estimates from the Center for Disease Control and Prevention. Unfortunately, many players don’t realize when they’ve suffered a concussion, or they feel competitive pressures to ignore the symptoms and quickly return to play. Returning too soon can lead to further brain trauma–and eventually to early dementia and other signs of severe brain damage. Two high-profile cases came to light this year: neurologists say that repetitive concussion is the likely cause of brain damage in retired NFL defensive back Andre Waters, who committed suicide last year, and retired NFL linebacker Ted Johnson, who suffers from severe depression.

Brain injury: This image shows abnormal brain activity in a patient who suffered a concussion after a car accident. Red represents overactivity and blue represents underactivity. Brain activity was recorded using EEG and then mapped onto a 3-D model of the brain. Scientists hope that this type of analysis will help detect concussions in athletes.

To address the problems, scientists are now trying to better understand concussion and find ways to quickly and objectively measure its severity. In one promising approach, researchers at New York University soon plan to test a handheld device to assess brain injury on the field.

“It would be a massive breakthrough to have a precise measure where you could wave a wand over an athlete and say, Yes, you have a concussion,” says Chris Nowinski, a former college-football player and professional wrestler, now president of the Sport Legacy Institute, an organization based in Waltham, MA, that educates athletes about the danger of repetitive brain injuries.

Previous research has shown that concussion briefly changes the chemistry in the brain, generating a flurry of brain activity similar to a seizure. That activity leaves brain cells especially vulnerable. “The mechanism to deliver fuel to cells is damaged, and if the brain is subjected to another insult, the cells will die,” says David Hovda, the director of the Neurotrauma Laboratory at the University of California, Los Angeles. Over time, damage accumulates, leaving lasting impairments in memory and attention.

Coaches and trainers routinely use crude memory tests to determine if a player can get back on the field. While these quick tests can detect major memory problems, they may miss more subtle cognitive dysfunction. “There is no clear protocol for when it’s safe to send players back into games,” says Nowinski. “Right now, we are without any technology to quickly–in under 20 minutes–and objectively diagnose mild traumatic brain injury.”

An experimental handheld device that uses electroencephalogram (EEG) to read the brain’s electrical activity might help. Under development by Roy John, director of the Brain Research Laboratories at New York University, and by Brainscope, a technology company based in Chesterfield, MO, the device is made up of an adhesive strip lined with six electrodes attached to a small computer. After a blow to the head, the strip is affixed to the athlete’s forehead to record electrical activity, which is processed through a specialized algorithm and compared with a database of normal and abnormal electrical profiles. The processor then spits out a probability score predicting the likelihood of damage, says John.

Previous research has shown that this type of analysis correctly identified 90 percent of people who had previously had a concussion. But it’s not yet clear if this device will be able to detect abnormal activity immediately after brain injury. It’s currently being tested in the emergency rooms of three hospitals to determine if it can be used to quickly assess brain damage associated with motor accidents, stroke, seizure, and other sources of head trauma. Researchers will compare the readings with later diagnosis based on brain imaging and other measures.

John is also in talks with a college-football team to run a study specifically on sports-related concussion. In the proposed study, which he hopes to conduct this season, each player would have his brain’s electrical activity read at the beginning of the season, then again after a suspected concussion. The idea is to use the technology to search for an electrical signature of trauma.

Some scientists are skeptical that EEG will be able to pick up the sometimes subtle signals of brain injury. “EEGs have not been very sensitive to showing concussion,” says Robert Cantu, codirector of the Neurologic Sports Injury Center at Brigham and Women’s Hospital, in Boston. But both Cantu and Hovda emphasize that this kind of non-invasive, fast-acting device is worth testing.

“The nice thing about EEG, if it would work, is that it does not require individuals to respond,” says Hovda. “In my experience, athletes lie. If you ask how they feel, they say, ‘I feel great. I want to go back in.’ That’s their athletic training and competitiveness.”

Other scientists are trying to better define concussion in order to develop more-sensitive detection tools. Mark Lovell and his colleagues at the University of Pittsburgh School of Medicine used functional magnetic resonance imaging to measure brain activity in 200 high-school athletes with concussions, both right after injury and after the athlete had fully recovered. Athletes who had abnormal activity in the frontal cortex–the part of the brain that is likely to hit the skull when an athlete suddenly stops–initially scored lower on cognitive tests and had longer recovery times. When the patient’s symptoms went away, brain activity returned to normal.

“These findings will help better define what recovery is,” says Lovell. “If an athlete isn’t reporting symptoms correctly, doctors could send someone back in who is in danger of having severe brain injury.”

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