Concussion is a trauma-induced change in mental status, with confusion and
amnesia, and with or without a brief loss of consciousness.
A concussion occurs when the head hits or is hit by an object, or when the
brain is jarred against the skull with sufficient force to cause temporary
loss of function in the higher centers of the brain. The injured person
may remain conscious or lose consciousness briefly and is disoriented for
some minutes after the blow.
According to the Centers for Disease Control and Prevention, approximately
300,000 people sustain mild to moderate sports-related brain injuries each
year, most of them young men between 16 and 25 years of age.
The risk of concussion from football is extremely high, especially at the
high school level. Studies show that approximately one in five players
suffer concussion or more serious brain injury during their brief
high-school careers. The rate at the collegiate level is approximately one
in 20. Rates for hockey players are not known as certainly but are
believed to be similar.
Causes and symptoms
Most concussions are caused by motor vehicle accidents and
. In motor vehicle accidents, concussion can occur without an actual blow
to the head. Instead, concussion occurs because the skull suddenly
decelerates or stops, which causes the brain to be jarred against the
, especially football, hockey, and boxing, are among those most likely to
lead to concussion. Other significant causes include falls, collisions, or
blows due to bicycling, horseback riding, skiing, and soccer.
Concussion and lasting brain damage is an especially significant risk for
boxers, since the goal of the sport is, in fact, to deliver a concussion
to the opponent. For this reason, the American Academy of Neurology has
called for a ban on boxing. Repeated concussions over months or years can
. The cumulative brain injuries suffered by most boxers can lead to
permanent brain damage. Multiple blows to the head can cause punch-drunk
syndrome or dementia pugilistica, as evidenced by Muhammad Ali, whose
Parkinson's is a result of his career in the ring.
Young children are likely to suffer concussions from falls or collisions
on the playground or around the home.
is, unfortunately, another common cause of concussion.
Symptoms of concussion include the following:
These symptoms may last from several minutes to several hours. More severe
or longer-lasting symptoms may indicate more severe brain injury. The
person with a concussion may or may not lose consciousness from the blow;
if he does lose consciousness, it will be for several minutes at the most.
Prolonged unconsciousness indicates more severe brain injury.
The severity of concussion is graded on a three-point scale, used as a
basis for treatment decisions.
Days or weeks after the accident, the person may show signs of the
The occurrence of such symptoms is called "post-concussion
A doctor should be consulted whenever a head injury causes any of the
symptoms noted above.
It is very important for those attending an individual with a concussion
to pay close attention to the person's symptoms and progression
immediately after the accident. The duration of unconsciousness and degree
of confusion are very important indicators of the severity of the injury
and help guide the diagnostic process and treatment decisions.
A doctor, nurse, or emergency medical technician may make an immediate
based on the severity of the symptoms; a
of the pupils, coordination, and sensation, and brief tests of
orientation, memory, and concentration. Those with very mild concussions
may not need to be hospitalized or have expensive diagnostic tests.
Questionable or more severe cases may require
scan (CT) or
magnetic resonance imaging
(MRI) scans to look for brain injury.
The symptoms of concussion usually clear quickly and without lasting
effect, if no further injury is sustained during the healing process.
Guidelines for returning to sports activities are based on the severity of
A grade 1 concussion can usually be treated with rest and continued
observation alone. The person may return to sports activities that same
day, but only after examination by a trained professional, and after all
symptoms have completely resolved. If the person
sustains a second concussion of any severity that same day, he or she
should not be allowed to continue contact sports until he or she has been
symptom-free, during both rest and activity, for one week.
A person with a grade 2 concussion must discontinue sports activity for
the day, should be evaluated by a trained professional, and should be
observed closely throughout the day to make sure that all symptoms have
completely cleared. Worsening of symptoms or continuation of any symptoms
beyond one week indicates the need for a CT or MRI scan. Return to contact
sports should only occur after one week with no symptoms, both at rest and
during activity, and following examination by a physician. Following a
second grade 2 concussion, the person should remain symptom-free for two
weeks before resuming contact sports.
A person with a grade 3 concussion (involving any loss of consciousness,
no matter how brief) should be examined by a medical professional either
on the scene or in an emergency room. More severe symptoms may warrant a
CT or MRI scan, along with a thorough neurological and physical exam. The
person should be hospitalized if any abnormalities are found or if
confusion persists. Prolonged unconsciousness and worsening symptoms
require urgent neurosurgical evaluation or transfer to a trauma center.
Following discharge from professional care, the person is closely
monitored for neurological symptoms that may arise or worsen. If headaches
or other symptoms worsen or last longer than one week, a CT or MRI scan
should be performed. Contact sports are avoided for one week following
unconsciousness of only seconds, and for two weeks for unconsciousness of
a minute or more. A person receiving a second grade 3 concussion should
avoid contact sports for at least a month after all symptoms have cleared
and then engage in the sport only with the approval of a physician. If
signs of brain swelling or bleeding are seen on a CT or MRI scan, the
athlete should not return to the sport for the rest of the season, or even
For someone who has sustained a concussion of any severity, it is
critically important that he or she avoid the possibility of another blow
to the head until well after all symptoms have cleared to prevent
second-impact syndrome. The guidelines above are designed to minimize the
risk of this syndrome.
Concussion usually leaves no lasting neurological problems. Nonetheless,
may last for weeks or even months.
Studies of concussion in contact sports have shown that the risk of
sustaining a second concussion is even greater than it was for the first
if the person continues to engage in the sport.
While concussion usually resolves on its own without lasting effect, it
can set the stage for a much more serious condition. Second impact
syndrome occurs when a person with a concussion, even a very mild one,
suffers a second blow before fully recovering from the first. The brain
swelling and increased intracranial pressure can lead to a potentially
fatal result. More than 20 such cases have been reported since the
syndrome was first described in 1984.
Many cases of concussion can be prevented by using appropriate protective
equipment. This includes seat belts and air bags in automobiles and
helmets in all contact sports. Helmets should also be worn while
bicycling, skiing, or horseback riding. Soccer players should avoid
heading the ball when it is kicked at high velocity from close range. The
surfaces immediately below and surrounding playground equipment should be
covered with soft material, either sand or special matting.
The value of high-contact sports such as boxing, football, or hockey
should be weighed against the high risk of brain injury during a young
person's participation in the sport. Steering a child's
general enthusiasm for sports into activities less apt to produce head
impacts may reduce the likelihood of brain injury. Children participating
in any contact sport or activity that can cause brain injury should always
wear a helmet.
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American Academy of Emergency Medicine.
611 East Wells Street, Milwaukee, WI 53202. Web site:
American Academy of Family Physicians.
11400 Tomahawk Creek Parkway, Leawood, KS 66211–2672. Web site:
American Academy of Neurology.
1080 Montreal Avenue, St. Paul, MN 55116. Web site:
American Academy of Pediatrics.
141 Northwest Point Boulevard, Elk Grove Village, IL 60007–1098.
Web site: http://www.aap.org/default.htm.
American College of Emergency Physicians.
PO Box 619911, Dallas, TX 75261–9911. Web site:
Brain Injury Association.
105 North Alfred Street, Alexandria, VA 22314. Web site:
International Brain Injury Association.
1150 South Washington Street, Suite 210, Alexandria, VA 22314. Web site:
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L. Fleming Fallon, Jr., MD, DrPH