Concussion

Definition

Concussion is a trauma-induced change in mental status, with confusion and amnesia, and with or without a brief loss of consciousness.

Description

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.

Demographics

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

Causes

Most concussions are caused by motor vehicle accidents and sports injuries . 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 skull. Contact sports , 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 cause cumulative head injury . 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. Child abuse is, unfortunately, another common cause of concussion.

Symptoms

Symptoms of concussion include the following:

• headache
• disorientation as to time, date, or place
• confusion
• dizziness
• vacant stare or confused expression
• incoherent or incomprehensible speech
• lack of coordination or weakness
• amnesia for the events immediately preceding the blow
• nausea or vomiting
• double vision
• ringing in the ears

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.

• Grade 1: no loss of consciousness, transient confusion, and other symptoms that resolve within 15 minutes
• Grade 2: no loss of consciousness, transient confusion, and other symptoms that require more than 15 minutes to resolve
• Grade 3: loss of consciousness for any period

Days or weeks after the accident, the person may show signs of the following:

• headache
• poor attention and concentration
• memory difficulties
• anxiety
• depression
• sleep disturbances
• light and noise intolerance

The occurrence of such symptoms is called "post-concussion syndrome."

When to call the doctor

A doctor should be consulted whenever a head injury causes any of the symptoms noted above.

Diagnosis

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 assessment based on the severity of the symptoms; a neurologic exam 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 computed tomography scan (CT) or magnetic resonance imaging (MRI) scans to look for brain injury.

Treatment

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 the concussion.

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 indefinitely.

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.

Prognosis

Concussion usually leaves no lasting neurological problems. Nonetheless, symptoms of post-concussion syndrome 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.

Prevention

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.

Parental concerns

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.

Resources

BOOKS

Hergenroeder, Albert C., and Joseph N. Chorley. "Head and Neck Injuries." In Nelson Textbook of Pediatrics, 17th ed. Edited by Richard E. Behrman, et al. Philadelphia: Saunders, 2003, pp. 2313–4.

Hodge, Charles J. "Head Injury." In Cecil Textbook of Medicine, 22nd ed. Edited by Lee Goldman, et al. Philadelphia: Saunders, 2003, pp. 2241–2.

Parker, Rolland S. Concussive Brain Trauma: Neurobehavioral Impairment and Maladaptation. Lakeland, FL: CRC Press, 2000.

Ropper, Allan H. "Traumatic Injuries of the Head and Spine." In Harrison's Principles of Internal Medicine, 15th ed. Edited by Eugene Braunwald, et al. New York: McGraw Hill, 2001, pp. 2434–41.

PERIODICALS

Iverson, G. L., et al. "Cumulative effects of concussion in amateur athletes." Brain Injury 18, no. 5 (2004): 433–43.

Lovell, M., et al. "Return to play following sports-related concussion." Clinics in Sports Medicine 23, no. 3 (2004): 421–41.

Ryan, L. M., and D. L. Warden. "Post concussion syndrome." International Review of Psychiatry 15, no. 4 (2004): 310–6.

Wisniewski, J. F., et al. "Incidence of cerebral concussions associated with type of mouth guard used in college football." Dental Traumatology 20, no. 3 (2004): 143–9.

ORGANIZATIONS

American Academy of Emergency Medicine. 611 East Wells Street, Milwaukee, WI 53202. Web site: <www.aaem.org/>.

American Academy of Family Physicians. 11400 Tomahawk Creek Parkway, Leawood, KS 66211–2672. Web site: <www.aafp.org/>.

American Academy of Neurology. 1080 Montreal Avenue, St. Paul, MN 55116. Web site: <www.aan.com/>.

American Academy of Pediatrics. 141 Northwest Point Boulevard, Elk Grove Village, IL 60007–1098. Web site: <www.aap.org/default.htm>.

American College of Emergency Physicians. PO Box 619911, Dallas, TX 75261–9911. Web site: <www.acep.org/>.

Brain Injury Association. 105 North Alfred Street, Alexandria, VA 22314. Web site: <www.biausa.org/Sportsfs.htm>.

International Brain Injury Association. 1150 South Washington Street, Suite 210, Alexandria, VA 22314. Web site: <www.internationalbrain.org/>.

WEB SITES

"Concussion." American Academy of Family Physicians. Available online at <www.aafp.org/afp/990901ap/990901e.html> (accessed December 8, 2004).

"Concussion." University of Missouri School of Medicine. Available online at <www.muhealth.org/~neuromedicine/concussion.shtml> (accessed December 8, 2004).

"Facts about Concussion and Brain Injury and Where to Get Help" Centers for Disease Control and Prevention. Available online at <www.cdc.gov/doc.do?id=0900f3ec8000d38c> (accessed December 8, 2004).

"Head Injury." MedlinePlus. Available online at <www.nlm.nih.gov/medlineplus/ency/article/000028.htm> (accessed December 8, 2004).

L. Fleming Fallon, Jr., MD, DrPH

KEY TERMS

Amnesia —A general medical term for loss of memory that is not due to ordinary forgetfulness. Amnesia can be caused by head injuries, brain disease, or epilepsy, as well as by dissociation. Includes: 1) Anterograde amnesia: inability to retain the memory of events occurring after the time of the injury or disease which brought about the amnesic state. 2) Retrograde amnesia: inability to recall the memory of events which occurred prior to the time of the injury or disease which brought about the amnesic state.

Parkinson's disease —A slowly progressive disease that destroys nerve cells in the basal ganglia and thus causes loss of dopamine, a chemical that aids in transmission of nerve signals (neurotransmitter). Parkinson's is characterized by shaking in resting muscles, a stooping posture, slurred speech, muscular stiffness, and weakness.

Concussion

Definition

Concussion is a trauma-induced change in mental status, associated with confusion and amnesia, that may or may not be accompanied by a brief loss of consciousness.

Description

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 briefly lose consciousness and become 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 the ages of 16 and 25.

While a 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 that can result is potentially fatal. More than 20 such cases have been reported since the syndrome was first described in 1984.

Causes and symptoms

Causes

Most concussions are caused by motor vehicle accidents and sports injuries . 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 skull. Contact sports, 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.

The risk of concussion from football is extremely high, especially at high school level. Studies show that approximately one out of every five players suffers a concussion or more serious brain injury during their brief high-school careers. The rate at the collegiate level is approximately one person in 20. Rates for hockey play- ers are not known with certainty but are believed to be similar.

A concussion is usually accompanied by another area of brain injury on the opposite side of the head from the initial blow. This is called a contrecoup injury. It is caused by to the impact of the brain on the opposite side of the skull after the initial blow.

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 cause cumulative head injury . 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 Muhammed Ali, whose Parkinson's disease 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. Child abuse is, unfortunately, another common cause of concussion.

Symptoms

Symptoms of concussion include:

• headache
• disorientation relative to time, date, or place
• amnesia for the events immediately preceding the blow
• confusion
• dizziness
• vacant stare or confused expression
• incoherent or incomprehensible speech
• incoordination or weakness
• nausea or vomiting
• double vision
• ringing in the ears (tinnitus)

These symptoms may last from several minutes to several hours. More severe or longer-lasting symptoms may indicate more severe brain injury. A person with a concussion may or may not lose consciousness from the blow. If consciousness is lost, the duration is usually brief, for several minutes at most. More prolonged unconsciousness indicates more severe brain injury.

The severity of concussion is graded on a three-point scale. This is used as a basis for treatment decisions.

• Grade 1: no loss of consciousness, transient confusion, and other symptoms that resolve within 15 minutes.
• Grade 2: no loss of consciousness, transient confusion, and other symptoms that require more than 15 minutes to resolve.
• Grade 3: loss of consciousness for any period of time.
• Days or weeks after the accident, a person may show signs of:
• headache
• poor attention and concentration
• memory difficulties
• anxiety
• depression
• sleep disturbances
• light and noise intolerance

The occurrence of such symptoms is called "post- concussion syndrome."

Diagnosis

It is very important for those attending a person 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 subsequent treatment decisions.

A trained health professional may make an immediate assessment based on the severity of the symptoms; a neurological exam of the pupils, coordination and sensation; and brief tests of orientation, memory, and concentration. Persons with very mild concussions may not need to be hospitalized or have expensive diagnostic tests. Questionable or more severe cases may require a computed tomography scan (CT) or magnetic resonance imaging (MRI) scan to look for brain injury.

Treatment

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 concussion.

A grade 1 concussion (no loss of consciousness, transient confusion, and other symptoms that resolve within 15 minutes) can usually be treated with rest and continued observation alone. The person may return to sports activities the 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, contact sports should be discontinued and not resumed until there have been no symptoms, during both rest and activity, for one week.

A person with a grade 2 concussion (no loss of consciousness, transient confusion, and other symptoms that require more than 15 minutes to resolve) 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, a person should be 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 should be avoided for one week following unconsciousness of only seconds, and for two weeks following 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 resume them only with the approval of a physician. If signs of brain swelling or bleeding are seen on a CT or MRI scan, an athlete should not return to the sport for the rest of the season at the earliest, if not indefinitely.

For someone who has sustained a concussion of any severity, it is critically important to 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.

Prognosis

A concussion usually leaves no lasting neurological problems. Nonetheless, symptoms of post-concussion syndrome 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 for the first, if the person continues to engage in the sport.

Health care team roles

A doctor, nurse, athletic trainer, or emergency medical technician may provide an initial evaluation at the time of the concussion. These health care team members can usually evaluate a grade 1 or 2 concussion. A neurologist, neurosurgeon, or trauma specialist should evaluate a concussion in a hospital. A neurologist or neurosurgeon should provide follow-up for grade 3 concussions. A nurse may provide post-concussion supportive care. Radiologists may obtain and interpret CT or MRI scans.

Prevention

Many cases of concussion can be prevented by using appropriate protective equipment. This includes using seat belts and air bags in automobiles, and wearing helmets in all contact sports. Helmets should also be worn when bicycling, skiing, or horseback riding. Soccer play- ers should avoid heading the ball when it is kicked at high velocity from close range. Playground equipment should be underlaid 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.

Resources

BOOKS

Adams, Raymond D, Victor, Maurice and Ropper, Allan H. Adam's & Victor's Principles of Neurology, 6th ed. New York: McGraw Hill, 1997.

Bailes, Julian E, Lovell, Mark R and Maroon, Joseph C. Sports Related Concussion. St. Louis, MO: Quality Medical Pub, 1998.

Parker, Rolland S. Concussive Brain Trauma: Neurobehavioral Impairment and Maladaptation. Boca Raton, FL: Lewis Publishers, 2000.

Rizzo, Matthew and Tranel, Daniel. Head Injury and Postconcussive Syndrome. London: Churchill Livingstone, 1996.

Wrightston, Philip and Gronwall, D.M.A. Mild Head Injury: A Guide to Management. New York: Oxford, 1999.

PERIODICALS

Bailes, J.E. and Cantu, R.C. "Head Injury in Athletes." Neurosurgery 48(1): 26-45, 2001.

Centers for Disease Control and Injury. Facts about Concussion and Brain Injury and Where to Get Help. Order electronically at: <http://webapp.cdc.gov/IXPRESS/PUBSPROD/NCIPC+BOOK/NCIPC.DML>.

Guskiewicz, K.M., Weaver, N.L., Padua, D.A. and Garrett, W.E. "Epidemiology of concussion in collegiate and high school football players." American Journal of Sports Medicine 28(5): 643-650, 2000.

Maroon, J.C., et al. "Cerebral concussion in athletes: evaluation and neuropsychological testing." Neurosurgery 47(3): 659-669, 2000.

Proctor, M.R. and Cantu, R.C. "Head and neck injuries in young athletes." Clinics in Sports Medicine 19(4): 693-715, 2000.

Reece, R.M. and Sege, R. "Childhood head injuries: accidental or inflicted?" Archives of Pediatric and Adolescent Medicine 154(1): 11-15, 2000.

ORGANIZATIONS

American Academy of Neurology, 1080 Montreal Avenue, St. Paul, Minnesota 55116. (651) 695-1940. Fax: (651) 695-2791. <http://www.aan.com>. info@aan.org.

American College of Sports Medicine, 401 W. Michigan St., Indianapolis, IN 46202-3233. (317) 637-9200. Fax: (317) 634-7817. <http://www.acsm.org,> mkeckhaver@acsm.org.

Brain Injury Association, 105 North Alfred Street, Alexandria, VA 22314. (800) 444-6443 or (703) 236-6000. Fax: (703) 236-6001. <http://www.biausa.org/Sportsfs.htm>. prevention@biausa.org.

International Brain Injury Association, 1150 South Washington Street, Suite 210, Alexandria, VA 22314.(703) 683-8400. Fax: (703) 683-8996. <http://www.internationalbrain.org>. info@internationalbrain.org.

National Center for Injury Prevention and Control, Centers for Disease Control and Prevention, Mailstop F41, 4770 Buford Highway NE, Atlanta, GA 30341-3724. (770) 488-4031. Fax: (770) 488-4 <http://www.cdc.gov/ncipc/dacrrdp/tbi.htm>. dardinfo@cdc.gov.

OTHER

American Academy of Family Physicians. <http://www.familydoctor.org/handouts/458.html>.

Head Injury Hotline. <http://www.headinjury.com/faqpcs.htm>.

Pashby Sport Concussion Safety. <http://www.concussionsafety.com/>.

University of California Los Angeles. <http://www.neurosurgery.ucla.edu/Diagnoses/BrainInjury/BrainInjuryDis_6.html>.

University of Missouri Health Center. <http://www.muhealth.org/~neuromedicine/concussion.shtml>.

KEY TERMS

Amnesia —A loss of memory that may be caused by brain injury, such as concussion; the loss may be temporary or permanent.

Contrecoup injury —An injury, usually involving the brain, in which the tissue damage is on the side opposite the site of the trauma.

Parkinson's disease —A neurological disorder that includes a fine tremor, muscular weakness and rigidity, and an altered way of walking.

Tinnitus —A sensation of ringing in the ears in the absence of external sources of noise.

L. Fleming Fallon, Jr., MD, PhD, DrPH

Concussion

Definition

Concussion is a trauma-induced change in mental status, associated with confusion and amnesia, that may or may not be accompanied by a brief loss of consciousness.

Description

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 briefly lose consciousness and become 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 the ages of 16 and 25.

While a 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 that can result is potentially fatal. More than 20 such cases have been reported since the syndrome was first described in 1984.

Causes and symptoms

Causes

Most concussions are caused by motor vehicle accidents and sports injuries. 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 skull. Contact sports, 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.

The risk of concussion from football is extremely high, especially at high school level. Studies show that approximately one out of every five players suffers a concussion or more serious brain injury during their brief high-school careers. The rate at the collegiate level is approximately one person in 20. Rates for hockey players are not known with certainty but are believed to be similar.

A concussion is usually accompanied by another area of brain injury on the opposite side of the head from the initial blow. This is called a contrecoup injury. It is caused by to the impact of the brain on the opposite side of the skull after the initial blow.

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 cause cumulative head injury. 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 disease 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. Child abuse is, unfortunately, another common cause of concussion.

Symptoms

Symptoms of concussion include:

• headache
• disorientation relative to time, date, or place
• amnesia for the events immediately preceding the blow
• confusion
• dizziness
• vacant stare or confused expression
• incoherent or incomprehensible speech
• incoordination or weakness
• nausea or vomiting
• double vision
• ringing in the ears (tinnitus)

These symptoms may last from several minutes to several hours. More severe or longer-lasting symptoms may indicate more severe brain injury. A person with a concussion may or may not lose consciousness from the blow. If consciousness is lost, the duration is usually brief, for several minutes at most. More prolonged unconsciousness indicates more severe brain injury.

The severity of concussion is graded on a three-point scale. This is used as a basis for treatment decisions.

• Grade 1: no loss of consciousness, transient confusion, and other symptoms that resolve within 15 minutes.
• Grade 2: no loss of consciousness, transient confusion, and other symptoms that require more than 15 minutes to resolve.
• Grade 3: loss of consciousness for any period of time.

Days or weeks after the accident, a person may show signs of:

• headache
• poor attention and concentration
• memory difficulties
• anxiety
• depression
• sleep disturbances
• light and noise intolerance

The occurrence of such symptoms is called "post-concussion syndrome."

Diagnosis

It is very important for those attending a person 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 subsequent treatment decisions.

A trained health professional may make an immediate assessment based on the severity of the symptoms; a neurological exam of the pupils, coordination and sensation; and brief tests of orientation, memory, and concentration. Persons with very mild concussions may not need to be hospitalized or have expensive diagnostic tests. Questionable or more severe cases may require a computed tomography scan (CT) or magnetic resonance imaging (MRI) scan to look for brain injury.

Treatment

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 concussion.

A grade 1 concussion (no loss of consciousness, transient confusion, and other symptoms that resolve within 15 minutes) can usually be treated with rest and continued observation alone. The person may return to sports activities the 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, contact sports should be discontinued and not resumed until there have been no symptoms, during both rest and activity, for one week.

A person with a grade 2 concussion (no loss of consciousness, transient confusion, and other symptoms that require more than 15 minutes to resolve) 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, a person should be 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 should be avoided for one week following unconsciousness of only seconds, and for two weeks following 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 resume them only with the approval of a physician. If signs of brain swelling or bleeding are seen on a CT or MRI scan, an athlete should not return to the sport for the rest of the season at the earliest, if not indefinitely.

For someone who has sustained a concussion of any severity, it is critically important to 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.

Prognosis

A concussion usually leaves no lasting neurological problems. Nonetheless, symptoms of post-concussion syndrome 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 for the first, if the person continues to engage in the sport.

Health care team roles

A doctor, nurse, athletic trainer, or emergency medical technician may provide an initial evaluation at the time of the concussion. These health care team members can usually evaluate a grade 1 or 2 concussion. A neurologist, neurosurgeon, or trauma specialist should evaluate a concussion in a hospital. A neurologist or neurosurgeon should provide follow-up for grade 3 concussions. A nurse may provide post-concussion supportive care. Radiologists may obtain and interpret CT or MRI scans.

Prevention

Many cases of concussion can be prevented by using appropriate protective equipment. This includes using seat belts and air bags in automobiles, and wearing helmets in all contact sports. Helmets should also be worn when bicycling, skiing, or horseback riding. Soccer players should avoid heading the ball when it is kicked at high velocity from close range. Playground equipment should be underlaid 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.

KEY TERMS

Amnesia— A loss of memory that may be caused by brain injury, such as concussion; the loss may be temporary or permanent.

Contrecoup injury— An injury, usually involving the brain, in which the tissue damage is on the side opposite the site of the trauma.

Parkinson's disease— A neurological disorder that includes a fine tremor, muscular weakness and rigidity, and an altered way of walking.

Tinnitus— A sensation of ringing in the ears in the absence of external sources of noise.

Resources

BOOKS

Adams, Raymond D, Victor, Maurice and Ropper, Allan H. Adams & Victor's Principles of Neurology, 6th ed. New York: McGraw Hill, 1997.

Bailes, Julian E, Lovell, Mark R, and Maroon, Joseph C. Sports Related Concussion. St. Louis, MO: Quality Medical Pub, 1998.

Parker, Rolland S. Concussive Brain Trauma: Neurobehavioral Impairment and Maladaptation. Boca Raton, FL: Lewis Publishers, 2000.

Rizzo, Matthew, and Tranel, Daniel. Head Injury and Postconcussive Syndrome. London: Churchill Livingstone, 1996.

Wrightston, Philip, and Gronwall, DMA. Mild Head Injury: A Guide to Management. New York: Oxford, 1999.

PERIODICALS

Bailes, J.E., and Cantu, R.C. "Head Injury in Athletes." Neurosurgery 48, no. 1 (2001): 26-45.

Centers for Disease Control and Injury. Facts about Concussion and Brain Injury and Where to Get Help. Order electronically at: 〈http://webapp.cdc.gov/IXPRESS/PUBSPROD/NCIPC+BOOK/NCIPC.DML〉.

Guskiewicz, K.M., Weaver, N.L., Padua, D.A. and Garrett, W.E. "Epidemiology of concussion in collegiate and high school football players." American Journal of Sports Medicine 28, no. 5 (2000): 643-650.

Maroon, J.C., et al. "Cerebral concussion in athletes: evaluation and neuropsychological testing." Neurosurgery 47, no. 3 (2000): 659-669.

Proctor, M.R., and Cantu, R.C. "Head and neck injuries in young athletes." Clinics in Sports Medicine 19, no. 4 (2000): 693-715.

Reece, R.M., and Sege, R. "Childhood head injuries: accidental or inflicted?" Archives of Pediatric and Adolescent Medicine 154, no. 1 (2000): 11-15.

ORGANIZATIONS

American Academy of Neurology. 1080 Montreal Avenue, St. Paul, Minnesota 55116. (651) 695-1940. Fax: (651) 695-2791. 〈http://www.aan.com〉. info@aan.org.

American College of Sports Medicine. 401 W. Michigan St., Indianapolis, IN 46202-3233. (317) 637-9200. Fax: (317) 634-7817. 〈http://www.acsm.org,〉 mkeckhaver@acsm.org.

Brain Injury Association. 105 North Alfred Street, Alexandria, VA 22314. (800) 444-6443 or (703) 236-6000. Fax: (703) 236-6001. www.biausa.org/Sportsfs.htm. prevention@biausa.org.

International Brain Injury Association. 1150 South Washington Street, Suite 210, Alexandria, VA 22314. (703) 683-8400. Fax: (703) 683-8996. 〈http://www.internationalbrain.org〉. info@internationalbrain.org.

National Center for Injury Prevention and Control, Centers for Disease Control and Prevention. Mailstop F41, 4770 Buford Highway NE, Atlanta, GA 30341-3724. (770) 488-4031. Fax: (770) 488-4338. 〈http://www.cdc.gov/ncipc/dacrrdp/tbi.htm〉. dardinfo@cdc.gov.

OTHER

American Academy of Family Physicians. 〈http://www.familydoctor.org/handouts/458.html〉.

Head Injury Hotline. 〈http://www.headinjury.com/faqpcs.htm〉.

Pashby Sport Concussion Safety. 〈http://www.concussionsafety.com/〉.

University of California Los Angeles. 〈http://www.neurosurgery.ucla.edu/Diagnoses/BrainInjury/BrainInjuryDis_6.html〉.

University of Missouri Health Center. 〈http://www.muhealth.org/∼neuromedicine/concussion.shtml〉.

Concussion

Definition

Concussion is a trauma-induced change in mental status, with confusion and amnesia, and with or without a brief loss of consciousness.

Description

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.

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 that can result is potentially fatal. More than 20 such cases have been reported since the syndrome was first described in 1984.

Causes and symptoms

Causes

Most concussions are caused by motor vehicle accidents and sports injuries. 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 skull. Contact sports, 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.

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.

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 cause cumulative head injury. 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 Muhammaed Ali, whose parkinsonism 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. Child abuse is, unfortunately, another common cause of concussion.

Symptoms

Symptoms of concussion include:

• headache
• disorientation as to time, date, or place
• confusion
• dizziness
• vacant stare or confused expression
• incoherent or incomprehensible speech
• incoordination or weakness
• amnesia for the events immediately preceding the blow
• nausea or vomiting
• double vision
• ringing in the ears

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 so, it will be for several minutes at the most. More 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.

• Grade 1: no loss of consciousness, transient confusion, and other symptoms that resolve within 15 minutes.
• Grade 2: no loss of consciousness, transient confusion, and other symptoms that require more than 15 minutes to resolve.
• Grade 3: loss of consciousness for any period.

Days or weeks after the accident, the person may show signs of:

• headache
• poor attention and concentration
• memory difficulties
• anxiety
• depression
• sleep disturbances
• light and noise intolerance

The occurrence of such symptoms is called "post-concussion syndrome."

Diagnosis

It is very important for those attending a person with 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 assessment based on the severity of the symptoms; a neurologic exam 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 computed tomography scan (CT) or magnetic resonance imaging (MRI) scans to look for brain injury.

Treatment

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 the concussion.

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 patient is closely monitored for neurological symptoms which 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 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 indefinitely.

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.

Prognosis

Concussion usually leaves no lasting neurological problems. Nonetheless, symptoms of post-concussion syndrome 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.

Prevention

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 when bicycling, skiing, or horseback riding. Soccer players should avoid heading the ball when it is kicked at high velocity from close range. Playground equipment should be underlaid 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.

Resources

BOOKS

Evans, R. Neurology and Trauma. W. B. Saunders Co., 1996.

ORGANIZATIONS

American Academy of Neurology. 1080 Montreal Ave., St. Paul, MN 55116. (612) 695-1940. 〈http://www.aan.com〉.

KEY TERMS

Amnesia— A loss of memory that may be caused by brain injury, such as concussion.

Parkinsonism— A neurological disorder that includes a fine tremor, muscular weakness and rigidity, and an altered way of walking.

CONCUSSION

DEFINITION

Concussion is a change in mental status caused by trauma (shock). It is accompanied by confusion, loss of memory, and, sometimes, loss of consciousness.

DESCRIPTION

A concussion occurs when the head hits or is hit by an object. A concussion can also occur when the brain is pushed against the skull with a strong force. In such cases, parts of the brain that control mental function may be damaged. The injured person may become disoriented (confused) and may briefly lose consciousness.

The U.S. Centers for Disease Control and Prevention (CDC) estimates that about three hundred thousand people experience mild to moderate concussions each year as a result of sports injuries. Most of these people are men between the ages of sixteen and twenty-five.

A concussion usually gets better without any long-term effect. On rare occasions, it is followed by a more serious injury called second-impact syndrome. Second-impact syndrome occurs when the head receives a second blow before the original concussion totally healed. Brain swelling may increase, resulting in a fatal condition. Since 1984, more than twenty people have died from second-impact syndrome.

CAUSES

Motor vehicle accidents and sports injuries are the major causes of concussion. In motor vehicle accidents, concussion can occur without an actual blow to the head. Instead, concussion occurs when the vehicle starts or stops suddenly. In such a case, the brain is pushed strongly against the skull. Contact sports, especially football, hockey, and boxing, are leading causes of concussion. Other significant causes are falls, collisions, or injuries due to bicycling, horseback riding, skiing, and soccer.

The risk of concussion from football is extremely high, especially at the high school level. Research shows that about 1 in 5 high school football players suffer concussion or more serious brain injury at some point during their high school football career. The comparable rate at the college level is 1 in 20.

Concussion and lasting brain damage is also very common among boxers. After all, the goal of this sport is to knock out an opponent, that is, to give him or her a concussion. For this reason, the American Academy of Neurology (a group of doctors who specialize in problems of the nervous system) has called for a ban on boxing.

Concussion: Words to Know

Amnesia:

Loss of memory sometimes caused by a brain injury, such as concussion.

Parkinson's disease:

A disorder of the nervous system that includes shaking, muscular weakness, stiffness, and problems with walking.

Repeated concussions over many months or years can eventually cause more serious brain injury. For example, boxers can develop a form of permanent brain damage called "punch drunk" syndrome or dementia pugilistica (pronounced dih-MEN-sha pyoo-juh-LIS-tuh-kuh). Perhaps the best known example is the great boxer Muhammad Ali. Ali eventually developed Parkinson's disease (see Parkinson' disease entry), believed to be caused by head injuries sustained while he was active as a boxer.

Young children are likely to suffer concussions from falls or bumps on the playground or at home. Child abuse is another common cause of concussion.

SYMPTOMS

Symptoms of concussion include:

• Headache
• Disorientation (confusion) as to time, date, or place
• Dizziness
• Vacant stare or confused expression
• Speech that is difficult to understand
• Lack of coordination or weakness
• Amnesia (loss of memory) about events just preceding the blow
• Nausea or vomiting
• Double vision
• Ringing in the ears

These symptoms may last from several minutes to several hours. More severe or longer-lasting symptoms may indicate more severe brain injury. If a person loses consciousness, it will be for several minutes at the most. If unconsciousness last for a longer period, a more serious form of brain injury may have occurred.

Doctors use a three-point system to determine the seriousness of a concussion. This system helps them to choose the appropriate treatment.

• Grade 1: No loss of consciousness, brief confusion, and other symptoms that clear up within 15 minutes.
• Grade 2: No loss of consciousness, brief confusion, and other symptoms that clear up in more than 15 minutes.
• Grade 3: Loss of consciousness for any period of time.

Days or weeks after the original concussion, certain symptoms may reoccur. These symptoms are called post-concussion syndrome. They include:

• Headache
• Loss of ability to concentrate and pay attention
• Anxiety
• Depression
• Sleep disturbance
• Inability to tolerate light and noise.

DIAGNOSIS

Anyone who receives a concussion must be watched very carefully after the accident. It is important to notice how long unconsciousness lasts and how

serious the symptoms seem to be. These signs are indications of how serious the brain injury was, and are important in deciding how to treat the patient.

A medical professional can decide how serious a concussion is with some simple tests. He or she may examine the pupils of the patient's eyes, test the patient's coordination and sense of feeling, and observe his or her memory, orientation, and concentration. Patients with mild concussions do not require hospitalization or further tests. Those with more serious injuries may need some form of brain test, such as a computer-aided tomographic (CAT) scan.

TREATMENT

The symptoms of concussion usually clear up quickly and without lasting effects. Medical specialists decide how soon a person can return to sports activities based on the severity of his or her injury. All treatment plans are designed to prevent a second blow to the head during recovery. A second blow may cause very serious long-term brain damage.

A Grade 1 concussion is usually treated with rest and continued observation only. The person can return to sports activities the same day if a medical professional approves and all symptoms are gone. If a second concussion occurs on the same day, the person should not be allowed to continue contact sports until he or she is free of symptoms for one week.

A person with a Grade 2 concussion must discontinue sports activities for the day. He or she must be observed by a medical professional and be observed throughout the day until all symptoms have disappeared. If symptoms become worse or continue beyond a week, further brain tests, such as a CAT scan, may be necessary. The person cannot return to contact sports until one week after symptoms have disappeared and a medical professional has given permission.

A person with a Grade 3 concussion should be seen immediately by a medical professional. If symptoms are severe, brain tests and hospitalization may be necessary. Prolonged unconsciousness and worsening symptoms require immediate examination by a neurologist.

A neurologist is a doctor who specializes in problems of the nervous system. The patient should be carefully observed after discharge from medical care. If symptoms reappear or become worse, further neurological tests may be necessary.

A person with a Grade 3 concussion should avoid contact sports for at least a month after all symptoms have disappeared. If brain tests indicate that brain swelling or bleeding has occurred, the athlete should give up contact sports for the season and, if symptoms are bad enough, indefinitely.

PROGNOSIS

There are usually no long-term effects of concussion. However, symptoms of post-concussion syndrome may last for weeks or months. The risk of a second concussion in contact sports is even higher than the risk for a first concussion. For that reason, a person who has received a concussion needs to avoid contact sports until the first concussion has entirely cleared up.

PREVENTION

Many cases of concussion can be prevented by using certain types of protective equipment. These include seat belts and air bags in cars, and helmets in contact sports. Helmets should also be worn when bicycling, skiing, or horseback riding. Soft material, such as sand or matting, should be placed under playground equipment.

Young people should think about the value of high-contact sports, such as boxing, football, and hockey, compared to their risk for head injuries. They may decide to take part in sports activities that are fun to participate in, but less risky to one's health.

FOR MORE INFORMATION

Books

Gronwall, D. M. A., Philip Wrightson, and Peter Waddell. Head Injury—The Facts: A Guide for Families and Care-Givers. New York: Oxford University Press, 1998.

Stoler, Diane Roberts. Coping With Mild Traumatic Brain Injury. Garden City Park, NY: Avery Publishing Group, 1998.

Organizations

American Academy of Neurology. 1080 Montreal Avenue St. Paul, MN 55116–2325. (800) 879–1960.