Sports-related Concussion
By Robert Paras, M.D.

With the increased numbers of young people engaged in sports, the incidence of sports-related concussion or mild traumatic brain injury has increased. Up to 300,000 athletes suffer a concussion each year. Twenty percent of high school and ten percent of college football players sustain concussive injuries each year. In fact concussions make up to 6.2 % of all athletic injuries. High-risk sports include football, hockey, lacrosse, and soccer. In order to optimize the recovery from a concussive injury, it is important that parents and coaches familiarize themselves with the signs and symptoms of concussive injury, timetable for recovery, and return to play guidelines.

A concussion is a disturbance in brain function that occurs following either a blow to the head or as a result of the violent shaking of the head. A concussion produces a metabolic rather than an anatomic injury to the brain. In other words, a blow to the head sets in motion a complex cascade of events that leads to a temporary disruption of energy utilization in the brain and ineffective functioning of brain tissue. This does not appear to produce permanent injury in the vast majority of cases. However, research suggests that repeated injury, particularly during the recovery period, may result in more severe and, in some rare cases, lifethreatening injury.

The diagnosis of concussion is not always straightforward. Often there is no recallable trauma and associated loss of consciousness. The athlete may be unaware that he or she has suffered a concussive injury and may not immediately exhibit the usual signs of concussion. To complicate matters research has shown that athletes at all levels may minimize or hide symptoms to prevent their removal from play. This increases their potential for more severe injury.

The signs and symptoms of concussion are quite varied and depend on numerous factors, especially on the biomechanical forces involved and the areas of traumatized brain. An athlete may exhibit one or many symptoms. Signs include fluctuating levels of consciousness, disorientation, balance problems, memory and concentration problems, and change in personality and inappropriate emotions. Symptoms are also quite varied and may include headaches, ringing of the ears, nausea and feeling off balance, visual difficulty, feeling “out of it” or “hazy”, changes in sleep patterns. It is important to remember that some of these symptoms may be delayed in onset following an injury. In addition an athlete may not exhibit the majority of symptoms until two or three days following injury. Not all headaches following a head injury are medical emergencies. However, if an athlete has a severe or progressively worsening headache, especially when associated with vomiting or rapidly declining mental status, he or she should be transported immediately to a hospital emergency room.

It was previously thought that a concussion was severe only if the athlete sustained a loss of consciousness. This is not the case. Researchers from the University of Pittsburgh Medical Center studied 78 high school and college athletes who sustained a concussion. They recorded symptoms at the time of their injury and reassessed each athlete three days later with testing of their neurocognitive function. Amnesia, especially retrograde amnesia -- inability to recall events occurring during the period immediately preceding trauma -- was most predictive of difficulties at three days post-injury, not loss of consciousness.

Other predictors of severity of injury include complaints of headaches, age of athlete, and history of prior concussions. Headaches were the most commonly reported symptom and, when present, were associated with continued impairment. Athletes with more severe concussion often reported headaches as a predominant symptom. Younger athletes have been shown to recover much more slowly than older-aged athletes. On average it takes seven days for the high school athlete to recover from a concussion as compared to three days in their college-aged counterparts. Athletes with a history of three or more concussions are nine times more likely to have more severe symptoms with subsequent injury, three times more likely to sustain an additional injury, and usually recover more slowly.

Often athletes may sustain a mild concussion or “bell ringer”. Traditionally these athletes were allowed to return to play during a practice or game once they were symptom free. However concussion experts are calling for a change in the way this group of athletes is handled. This is based on a study, which looked at a group of 13 to 17 year old football players who sustained a mild concussion (defined as less than 15 minutes of on field symptoms). Using neurocognitive testing they showed that it took at least four days for symptoms to resolve and seven days for full recovery of neurocognitive function. In another study, a similar group of athletes were examined 36 hours after a mild concussive injury. Declines in memory functioning and increases in symptom reporting were demonstrated. As a result of these studies, concussion experts are advising that high school athletes who suffer from mild concussion not be allowed to reenter a game or return to a practice after sustaining a mild concussion.

A certified athletic trainer or medical professional familiar with concussive injuries and return to play guidelines should perform the immediate evaluation of the concussed athlete. If one is not available, then the athlete should be held out of the game and referred for proper assessment and care. A focused history regarding the mechanism of injury and general inventory of signs and symptoms of concussion should be performed with particular attention to the presence or absence of amnesia and loss of consciousness. Mental functioning (orientation, concentration, and memory) should be tested. A uniform format for testing should be used.

Traditionally, to indicate the severity of a concussive injury, a “grade” is often assigned after the initial evaluation. More than eight different grading schemes exist. This reflects the lack of consensus regarding the importance of specific signs and symptoms. These grading schemes overemphasize the loss or retention of consciousness and minimize other signs and symptoms, as well as the duration of symptoms. For example an athlete may present with complaints of headaches and dizziness -- without a loss of consciousness -- and still have a severe concussion. In contrast, according to some grading scales, an athlete with even the briefest loss of consciousness may be given a severe grade and withheld from participation for an undue period when in fact the injury may be mild.

American Academy of Orthopedic Sports Medicine called for an individualized data-driven approach to the concussed athlete. This has led to the development of computer-based neurocognitive testing. This testing assesses brain function by measuring performance in verbal memory, visual memory, reaction time, and processing speed. The athlete is also required to complete an inventory of concussion symptoms and to rate the severity of each symptom at the time of their testing. These “test scores” are compared to baseline or pre-injury test results. One can demonstrate depression of these scores following a concussive injury. As the athlete recovers from the injury the test scores return to baseline reflecting the normalization of brain function. This recovery should also be correlated with the resolution of symptoms.

Treatment of the concussed athlete is supportive and may include the use of analgesics such as acetaminophen and ibuprofen for headaches, adequate rest, nutrition, and hydration. In some cases an athlete may be required to briefly withdraw from school or may need academic accommodations as he or she recovers from the injury.

When the athlete is symptom free and demonstrates normalization of neurocognitive testing, return to participation is allowed. Often supervised sport-specific exercise testing under the direction of an athletic trainer is performed. If the athlete should exhibit a return of any symptoms during testing, return to play is not permitted and the athlete may be reevaluated after a further period of rest. Under no circumstances should an athlete be returned to play if he or she is symptomatic.

In order to optimize the care of the concussed athlete, parents and coaches must familiarize themselves with the various signs and symptoms of mild traumatic brain injury. The injured athlete should not be allowed to return to play in the same contest or practice after sustaining a concussion. It is important to remember that athletes can no longer be managed effectively with the self-report of symptoms alone. An effective management strategy incorporates the use of neurocognitive testing with the athlete’s report of symptoms to judge the severity of injury, monitor for injury resolution, and to guarantee a safe return to play.

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