WASHINGTON — From the glory years of Little League baseball through the golden years of geriatric rec-league sports, concussions are nasty injuries that plague every kind of athlete.
Classified by the Centers for Disease Control as a form of traumatic brain injury, sports concussions happen thousands of times a year in the U.S., and can leave a lasting impact upon the not-so-lucky recipient.
As public awareness of sports concussions has increased, organizations like the NFL, the NHL and the NCAA have tightened standards and practices for dealing with them. Just this week the NCAA released an official recommendation suggesting that all of its member universities create a detailed plan for dealing with concussed athletes.
For all the attention the traumatic injury has received lately, scientists and doctors still don’t fully understand everything there is to know about concussions. There is even controversy as to whether or not they should be called concussions or be diagnosed as different levels of traumatic brain injury.
“There is not as much known about concussions as you might think because they don’t generate really big, visible problems,” said Simon D’Alton, a neuroscience researcher at the Mayo Clinic in Jacksonville, Fla. “They generate very small, micro-structural problems that are really difficult to detect.”
The broad idea behind a concussion is that upon a force of impact to the head, the brain bangs around violently inside the skull, disrupting normal brain activity.
Upon closer observation, this disruption of neural function offers a fascinating look at how the brain unleashes hundreds of chemicals in order to protect itself after trauma—chemicals that can be harmful if the body or medicine do not rid them from the brain.
The process begins with the twisting and tearing of axons, which are fibers that act as communication highways between neurons (or nerve cells). Neurons, which are responsible for cognition, communicate with one another through electro-chemical impulses that are transmitted through the axons.
Inflammation of brain tissue can set in if the trauma is severe enough, when glial cells, which protect and support the neurons, become activated and release hundreds of chemicals to assist the injured tissue in recovery. The excess chemical material is what causes the brain to swell, sometimes to dangerous levels, and can actually poison the surrounding cells.
“The up-swelling of cells can help ameliorate an injury, but if those inflammatory responses are kept at a consistent level, it can lead to brain damage,” said Danny George, an assistant professor at the Penn State College of Medicine. “Inflammation can be toxic to cells if they’re exposed for too long a duration.”
Most concussions do not lead to this kind of extreme damage, but if the trauma is severe enough, and the force of impact causes the brain to bleed, serious long-term damage can be a possibility.
• Nearly half (47%) of all TBIs are the result of falling (28%) or having your head struck by or against an object (19%).
• Most concussed athletes don’t lose consciousness.
• Concussions can cause brain swelling so severe that procedures to remove part of the skull are sometimes the only way to reduce the pressure.
• People are told not to fall asleep after sustaining a concussion because they cannot detect symptoms, like progressive lethargy, that may alert them to the need for more medical attention.
• Emergency rooms see approximately 135,000 traumatic brain injuries a year from sports-related injuries in kids aged 5-18.
• People 19 and younger are at a higher risk to get a concussion than adults. They also take longer to recover.
(Courtesy of the CDC)
To reduce the swelling, the body’s endocrine system releases stress hormones like Cortisol, which a number of experts say decrease the inflammation.
Athletes can feel the adverse effects of a concussion for anywhere from a few days to a few months, and sometimes longer than a year. They can become sensitive to light and noise, get headaches, become nauseous or dizzy, feel confused or have memory problems. They can also become easily agitated, depressed or despondent.
Even more worrisome than short-term problems is the link being established by researchers between repeated head trauma and mental deterioration years after the injuries.
“There is some really strong epidemiological data linking earlier-life head injuries with early onset dementia later in life, and that is a fairly strongly established association,” said George, who teaches a medical school class on aging and dementia.
For athletes who want to get back in the game, a warning from the CDC: Getting a concussion increases the risk of getting another later on in life.