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Knock Knock: Concussions from Sports Injuries


   
by Rosemarie Scolaro Moser, PhD, ABPN
*Printed in NJ Medicine, November 1998. Pages 27-29.		  
   

Each year, 20 percent of the 1.54 million head injuries in the United States result from participation in sporting events. These events span the venues of school-related activities and recreational athletic leagues through professional sports. We need to educate professionals and the public with guidelines for the identification and management of sports-related concussion.

The medical community has become enlightened to the seriousness of concussion and to the misunderstanding and myths shared by sports personnel, athletes, medical professionals, and the public regarding concussion identification and treatment. The danger lies in the fact that an alarming number of athletes, coaches, and trainers do not know how to correctly identify concussions and that many physicians are not properly trained in "return to play" decision making.

A brain that has suffered concussion is more vulnerable to repeated hits. Having sustained one concussion increases the risk four to six times of sustaining another concussion. The effects of concussion are cumulative over the span of an athlete's career and, multiple concussions may increase the risk of degenerative brain diseases such as Alzheimer's, cerebral atrophy, and Parkinsonian-like symptomatology.

The statistics are frightening: one in five high school football players sustains a concussion each year; 50 percent of college athletes have had a history of concussion; 11 percent of ice hockey players, 17 percent of wrestlers, and 19 percent of baseball and softball players sustain concussions every season and 90 percent of boxers show neurological dysfunction. As the symptoms of concussion can be mild and insidious, often going unnoticed, it is likely that concussion is under-reported and that these statistics underestimate actual frequencies.
Cerebrospinal fluid acts as a shock absorber between the brain and the hard skull. But a swift, hard check to the body can result in the brain's brush against bony protuberances on the inside skull, as well as in the twisting of the brain, which is anchored at the brain stem. Diffuse axonal shearing occurs, which may not be detected by CT or MRI, often resulting in post-concussive symptoms. More severe injury, such as intracranial bleeding, subdural hematoma, and cerebral contusions, also may occur. However, in the absence of more severe injury, mild concussion promotes metabolic changes, which persist even after what may look like full recovery, thus increasing vulnerability to further damage. It is these metabolic changes due to repeated concussions that can cause dysfunction of the blood vessels and the cerebrovascular system. In the case where an athlete does not fully recover from a concussion and then experiences a second concussion, usually within a week's time, second impact syndrome may occur. This rare condition often is fatal due to rapid cerebral swelling. It most often occurs in young athletes and in children under the age of 21 years. Careful concussion assessment and identification are imperative to help prevent brain damage, post-concussion syndrome (PCS), and second impact syndrome. The American Academy of Neurology has published new guidelines identifying the different grades of concussion (Table 1). SCtable1
SCtable2 Generally, concussion can be diagnosed in the individual who exhibits any alteration in mental status, disorientation or confusion, delayed responses, amnesia, loss of consciousness, slurred speech, or vacant stare. Examination may indicate fixed or unequal pupils, revealing clear neurological involvement. Other symptoms of concussion, which may not be immediately ascertained, include headache, dizziness, nausea or vomiting, memory, attention or concentration difficulties, slowness in information processing, fatigue, and visual disturbance. Guidelines also have been provided for return to play decisions (Table 2). Nevertheless, even with these guidelines, there are no firm, scientifically validated criteria for return to play, so it is best to err on the side of safety. Furthermore, neurological and radiological procedures frequently are not sensitive to the effects of mild head injury, rendering medical diagnosis quite problematic.


Neuropsychological testing has proved to be more sensitive even to the subtle effects of a single mild concussion 24 hours post-injury. No athlete with any symptoms should return to play. Ultimately, the decision to return to play should be made by a team of individuals, which may include the physician, the athletic trainer, the coach, the player, the parent (in the case of minors), and the neuropsychologist.

The use of neuropsychological testing in professional athletes has become a standard that now is encouraged at the college and high school levels of play across the country. Neuropsychological testing is being used in preseason baseline testing of young athletes to determine their standard levels of neuropsychological functioning. Baselines provide data against which to compare test results that are gathered post-injury. A full, comprehensive neuropsychological evaluation is performed on an athlete after an injury has been sustained to more thoroughly assess areas of possible dysfunction or damage and to devise a cognitive rehabilitation treatment plan.

Cognitive rehabilitation can be helpful especially in the treatment of post-traumatic brain injury or post-concussion syndrome (PCS). PCS is an insidious disorder that often is misdiagnosed, dismissed, ignored, or denied. The afflicted individual will present with what seems to be vague psychological complaints. There may be problems with thought processing (memory, attention, concentration, forgetfulness), changes in mood (irritability, anxiety, depression, frustration), and physical complaints (headaches, dizziness, fatigue). The longer the disorder remains untreated, the more difficult the recovery and adjustment. Treatment for PCS can include cognitive rehabilitation, biofeedback, psychotherapy, pharmacotherapy, relaxation training, and hypnosis.

Efforts to structure sideline assessment of concussion have resulted in a number of sideline assessment tools, such as the Standardized Assessment of Concussion (SAC), which provides athletic trainers and others on the side-lines the opportunity to quickly screen for concussion in a structured, repeated way, assessing orientation, concentration, memory, and exertion.

In a sports-oriented society that promotes being tough on the field, playing through the injury, and not admitting to brain dysfunction, a Grade 1 or 2 concussion is anything but a "small head bonk." The denial of concussion in professional athletes is a grim event and in our youth is even more frightening. This denial begins early in youth sports, is reinforced by society and needs to be re-evaluated.