By Wayne K. Manness, MD and Edward W. Pegg, III, MD
Recently, concussion has become a major focus for medical professionals, athletic directors, parents, and athletes alike. This awareness is a result of a dramatic increase in our knowledge of concussion as well as increased media coverage. Several prominent professional athletes have been devastated by the long-term complications of traumatic brain injuries and many more have been diagnosed with Chronic Traumatic Encephalopathy (CTE), a form of brain damage caused by multiple concussive and subconcussive blows.
The current definition of concussion is “a trauma-induced alteration in mental status with or without a loss of consciousness.” Given this definition, many impacts in an athletic event could be considered “concussions.” However, all bumps to the head are not concussions; football, hockey, or soccer players may have numerous collisions during a game without incident. The best way to determine that an impact has caused a concussion is a change in the athlete’s wellbeing. This includes symptoms such as confusion, dizziness, blurred vision, headache, nausea, imbalance, memory loss, or change in awareness.
Following an impact, players should be assessed for the above symptoms and should be considered concussed if complaining of any of these symptoms. Concussed players must be examined by a medical specialist before they return to play. Early on, concussion guidelines were used in an effort to grade the severity of the concussion. These guidelines had no scientific backing or research to confirm their validity. Newer research indicates that there is no single symptom or constellation of symptoms that can determine severity. This has led to a policy of treating each concussed athlete individually. Players sometimes have imaging tests, such as CT scan or MRI, to evaluate for a traumatic injury to the brain.
The injured player may undergo a CT scan of the head, especially if there is a loss of consciousness or other indicators that bleeding may have occurred. CT is also useful to evaluate for fractures of the skull. Fortunately, bleeding in the brain and skull fractures are very uncommon in most sports-related concussions and since the introduction of helmets in football. These injuries are much more common with major trauma, such as motor vehicle accidents.
MRI is a sensitive test that shows brain tissue much better than CT. It can detect subtle bleeding or very small contusions (brain “bruises”). A relatively new MRI technique, called “susceptibility-weighted imaging (SWI)” is a very sensitive method to find post-traumatic bleeding in the brain. When contusions or bleeding are discovered, a more serious brain injury has occurred, not just a simple concussion. Another technique, called “diffusion tensor imaging (DTI)” measures the ability of water to move along the nerve fibers in the brain. Researchers have used these advanced techniques to evaluate major sports athletes as well as military combat veterans with head injuries. Their findings help us understand what damage occurs from certain types of injuries and can help guide development of better treatments for these patients.
Imaging tests looking for a structural change (CT and MRI) are usually negative after concussions. This is because most concussions do not result in structural damage to the brain. Concussions cause a change in function, not structure — it’s like a battery running out of charge but not broken. If the anatomy of the brain is not changed, there is nothing abnormal on the CT or MRI. The specialists have been able to work around this by using other tests to manage injured patients. Using neuro-psychological testing for “return-to-play” decisions is strongly supported by research. This is a computer-based test used to measure each player’s brain function individually. Each athlete takes a baseline test in the pre-season, before any injury has occurred. If an injury occurs, the player is tested against his or her own baseline after injury. It is a very accurate test because it compares the athlete’s mental ability after injury to his or her normal, healthy self.
We now understand that concussion causes a change in the metabolism and function of the brain cells. Cells lose their ability to regulate themselves and go into “hyperdrive,” burning up all their fuel (sugar and oxygen). During this time, it is critical that blood flow is maintained to replace the depleted energy stores. However, the blood vessels may spasm and decrease flow to the injured areas, putting the concussed areas of the brain at greater risk. If the athlete is kept at rest and given a proper healing period, one can expect a full recovery.
On the other hand, if an athlete returns to play too soon, they may face slow or incomplete healing. The biggest concern is if an athlete returns too soon and suffers another head injury. This can result in “second impact syndrome,” a potentially life-threatening condition.
Neuro-psychological testing, such as ImPACT, has become the cornerstone of concussion management, providing information beyond that obtained by imaging studies. Careful monitoring of each individual is required — not all brains will heal at the same rate. Repeating the test over time shows when the athlete’s brain function returns to his or her normal level, when it’s safe to be active again. Having this tool has made concussion more manageable, allowing players to return to the game safely.
If you are an athlete who suffers a concussion, remember these important facts. Even if you have a negative CT or MRI scan, your brain may still be injured. Neurological evaluation and neuro-psychological testing can show if you’ve suffered a brain injury and can show when your brain function returns to its normal level. Follow the appropriate steps before you return to play and make sure you give your brain time to heal!
For more information on MRI technology, you may contact Advanced MRI at 309-665-0640. They are located at 1709 Jumer Drive in Bloomington and they have the only 3T MRI scanner in the Bloomington-Normal area.
For more information on any neurological issue, including sports neurology and concussion management you may contact Dr. Pegg at 309-661-7344.
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