Sport-Related Concussion

Concussion is the most common head injury that occurs during sport participation, with more than 250,000 injuries reported annually in football players alone. In fact, 20% of high school football players experi-ence a concussion each year. Sport-related concussions are usually witnessed, are generally mild, are usually not associated with other injuries, and sometimes are treated initially by nonmedical personnel. Athletes most at risk for a sport-related concussion participate in football, boxing, hockey, lacrosse, rugby, equestrian events, and snow skiing.

What is a concussion?
A concussion is a temporary alteration in consciousness that occurs immediately after a blow to the head. The condition is the mildest form of traumatic (sudden, forceful) brain injury. However, the cumulative effect of having more than one concussion can be permanently damaging or deadly.

Symptoms
Concussions range in severity. A mild concussion disrupts function but does not render the athlete unconscious. The athlete may describe a feeling of having his or her "bell rung" and may be confused momentarily. The brain repairs itself quickly and completely. A moderate concussion results in longer lasting confusion and amnesia in the conscious athlete. For example, the athlete may not remember the events leading up to the injury or what period of the game it is. The brain has microscopic tissue damage that can take up to six months to repair completely. A severe concussion results in loss of consciousness and is treated as an emergency.

One severe concussion or successive mild or moderate concussions can cause permanent damage to the brain or can cause postconcussive syndrome. The symptoms of postconcussive syndrome include headaches, dizziness, insomnia, poor concentration, memory difficulties, irritability, personality changes, anxiety, or depression. As many as 30% of professional football players have symptoms of this disorder.

A rare and usually deadly result of concussion is second impact syndrome. This syndrome develops when an athlete receives another concussion before fully recovering from the previous concussion. The second concussion may occur after a seemingly minor injury such as a blow to the chest that is strong enough to jar the brain. After the injury, rapid, severe swelling of the brain leads to uncontrollably high pressure in the skull. At first, the athlete appears dazed, but, within a few seconds or minutes, he or she collapses and develops rapid dilation of pupils, loss of eye movement, and respiratory (breathing) failure.

Treatment
Because a concussion damages the brain, an athlete must be examined by a medical professional before returning to play. Several grading systems have been devised to help team doctors and certified athletic trainers (ATCs) examine an athlete with a sport-related concussion and prevent further, more serious brain damage. One of the most frequently used systems was developed by the Colorado Medical Society and is described here.

An athlete with a Grade 1 (mild) concussion must stop participating. He or she can return to play only if the examiner determines that nervous system function is normal and if no symptoms (i.e., amnesia, postconcussive syndrome) are displayed at rest and with exertion (e.g., running in place) for at least 20 minutes. Because another concussion during the same game is more likely now and can cause further damage, the doctor or ATC may consider barring the athlete from play that day.

After returning to play, the athlete must be examined regularly by the same doctor or ATC throughout competition. If symptoms appear, the athlete must stop competing that day and have a magnetic resonance imaging and a computed tomography (CT) scan to examine the brain.

If the athlete suffers a second Grade 1 concussion in the same game, he must stop playing that day. He or she can return to play only when symptoms have not been present for at least one week. After a third Grade 1 injury, competition ends for the season. The athlete can participate in contact sports (e.g., football, basketball) after three months only if symptoms are not present at rest and with exertion.

An athlete with a Grade 2 (moderate) concussion must stop participating in competition that day and must be re-examined by a doctor the next day. He or she can return to contact sports only if nervous system function is normal and no symptoms are present at rest and with exertion for at least one week.

After a second Grade 2 concussion, the athlete cannot return to play for at least one month and may be barred from play for the season. Suffering a third Grade 2 concussion ends play for the season.

A Grade 3 (severe) concussion is considered an emergency. The unconscious athlete must have the cervical (neck) spine immobilized as a precaution and must be transported by ambulance to a hospital for medical evaluation and a CT scan of the head. The athlete can go home under the supervision of a family member only when the results of the nervous system evaluation and the CT scan are normal. He or she can return to contact sports one month after injury only if no symptoms are present at rest and with exertion for at least two weeks.

After a second Grade 3 concussion, the athlete must stop participating for the season and must consider not returning to any contact sport.

If the athlete continues to have symptoms of postconcussive syndrome, he or she needs to see the doctor again. The doctor may prescribe mild analgesics to relieve some of the symptoms and may work with the athlete to rehabilitate brain function, thought processes, or behavior.

Prevention
Wearing a good quality helmet, wearing a mouthpiece, and strengthening the neck muscles can help prevent concussion. Although athletes may be eager to return to play, they need to be honest with the examiner, telling him or her exactly how they feel. Remember, each successive concussion causes more brain damage, which can lead to severe discomfort, permanent brain damage, or death.

Marc Goldman, M.D.
Columbus, Georgia

Further reading

  1. Youmans JR, ed. Neurological Surgery: A Comprehensive Reference Guide to the Diagnosis and Management of Neurosurgical Problems, fourth ed. Philadelphia, PA: W.B. Saunders Co., 1996;1533-1548, 1595-1617.
  2. Greenberg MS. Head trauma. In: Handbook of Neurosurgery, third ed. Lakeland, FL: Greenberg Graphics, Inc., 1994;521-569.
  3. Wojtys EM, Hovda D, Landry G, et al. Concussion in sports. Am J Sports Med 1999; 27(5):676-687.
  4. Jacko J. Head injuries. In: Baker CL, ed. The Hughston Clinic Sports Medicine Book. Philadelphia, PA: Williams & Wilkins, 1995; 112-117.