health

Concussion is defined as a closed-head injury (that is, one that does not
involve a skull fracture) usually caused by blunt-force impact. Concussion
was traditionally used by doctors to refer to temporary loss of consciousness
from a head injury, but in everyday language, the term
usually means any minor injury to the head or brain. Concussions
generally are not life-threatening but may involve long-term as well as
short-term health problems.

Concussion occurs when the brain is pushed against one side of the
skull, often by impact with a blunt object. The impact can result from
a person’s striking the head against an object as well as being hit by
something or someone. Athletic injuries are the most common cause of
concussions, but concussions can also result from automobile, bicycle, or
other transportation accidents, criminal assaults, workplace accidents, or
accidents in the home—particularly falls.

Concussions in Professional Sports

Several deaths among high-profile professional
athletes focused attention on the dangers
of ignoring or minimizing concussions—
particularly the long-term effects of repeated
head injuries. In 2006, Andre Waters, a professional
football player, committed suicide in
his Florida home. Waters’s suicide was preceded
in 2004 by the death of Justin Strzelczyk,
another football star, in an auto accident following
a 37-mile-long high-speed police chase
on the wrong side of the highway.
Christopher Nowinski, a former professional
wrestler whose career was ended by post-concussion
syndrome in 2003, decided to investigate
the effects of repeated concussions on
professional athletes. Nowinski contacted a
neurosurgeon at the University of Pittsburgh
who was able to obtain samples of the dead
football players’ brain tissues after contacting
their families. The doctor found that Waters’s
brain resembled that of an 85-year-old man
with Alzheimer disease, and that Strzelczyk’s
personality changes in the weeks preceding his
death could be traced to brain damage from
repeated concussions. In 2007 Nowinski
founded the Sports Legacy Institute, an organization
dedicated to researching sports-related
brain injuries in order to protect the health and
lives of all athletes.

1. Definition .
   
2. Description .
   
3. Demographics .
   
4. Causes and Symptoms .
   
5. Diagnosis .
   
6. Treatment .
   
7. Prognosis .
   
8. Prevention .
   
9. The Future .
   

Concussions are probably underreported because many mild cases resolve
on their own and because many athletes do not want to miss scheduled
competitions. One estimate is that there are six cases of concussion per
1,000 people per year in the United States, but this figure is probably
too low.
Among children between the ages of five and fourteen, the most
common causes of concussions are sports and bicycle accidents; among
adults, the most common causes are falls and auto accidents. Soldiers
in combat may have rates of concussion from bomb blasts as high as
15 percent.
The sports that place participants at the highest risk of a concussion
are boxing, football, ice hockey, wrestling, rugby, and soccer. At the high
school level, girls are more likely to be injured than boys (in sports played
by both sexes) because of their smaller head and neck structure.
According to the American College of Sports Medicine, studies of high
school athletes show that the rate of concussions per 1,000 games is as
follows: 0.59 for football; 0.25 for wrestling; 0.18 for boys’ soccer and
0.23 for girls’ soccer; 0.09 for girls’ field hockey; and 0.11 for boys’ basketball
and 0.16 for girls’ basketball.

The basic cause of a concussion is the rotation of the brain inside the
skull as well as compression of the brain tissue against the sides of the
skull when a person receives a blow on the head. Although the brain is
cushioned against minor bumps by cerebrospinal fluid (CSF), the
amount of fluid between the brain and the skull is not enough to absorb
the force of a heavy blow.
Doctors do not agree as to whether concussion is a disturbance of
brain function only or whether it involves damage to the structure of the
brain as well. It is presently thought that the forces from a blow to the
head disrupt the normal activity of the cells in the brain tissue, and that
it is this disruption that causes temporary alterations in consciousness.

The brain’s secretion of neurotransmitters (the chemicals that convey
signals from one nerve cell to another), its oxygen supply, and its
use of glucose (blood sugar) are all affected by concussion.
In addition, a small number of cells in the brain tissue may die as
a result of even temporary interruptions of blood flow to the parts of
the brain affected by the concussion.

The symptoms of a concussion include emotional and well as cognitive and physical
symptoms:

• Physical symptoms: Headache (the most common symptom of concussion),
  dizziness,loss of balance or coordination, nausea and vomiting, visual
  disturbances,ringing in the ears, seizures or convulsions.
  
• Cognitive: Temporary loss or alteration of consciousness, difficulty
  concentrating, memory loss, confusion, disorientation, difficulty
  thinking clearly, disturbed sleep patterns.
  
• Emotional: Moodiness, tearfulness, temper outbursts, emotions
  inappropriate to a specificsituation (such as laughing at a funeral),
  long-term personality changes.
  

It is possible for a person to suffer a mild concussion
without knowing it, particularly if their
attention was focused on something else—such as getting out of a
damaged car, helping someone else to safety, or escaping from an
attacker. They may not seek medical help afterward. Most people, however,
will go to the doctor after a head injury if they have briefly lost consciousness,
are having prolonged vomiting spells, severe headaches, or such
vision problems as seeing double or seeing bright lights.
Because of the potential seriousness of a closed-head injury, the
doctor will take a careful history of the injury (its cause and other details
of the incident, as well as how long the patient was unconscious) as well
as a general medical history. The doctor will particularly need to know
whether the patient has had previous head injuries; is taking any bloodthinning
medications; or has a bleeding disorder.

The history is followed by several examinations and imaging studies:

• General physical examination. The doctor looks for injuries to the
  head and neck, including bleeding from the ears or nose, or other
  indications that the skull may have been fractured.
  
• Neurological examination. This part of the examination involves
  testing the patient’s reflexes, vision, hearing, balance, and
  coordination.
  
• A computed tomography (CT) scan. This type of imaging study is
  not always ordered if the concussion seems to have been mild. It is,
  however, usually performed if the patient is a child or elderly; is
  under the influence of alcohol or drugs; was injured in a motor
  vehicle accident; fell from a height of more than 3 feet (0.9 meters);
  cannot recall the accident or blow thirty minutes after it occurred;
  is having seizures; is vomiting; or is having trouble with short-term
  memory.
  
• Observation overnight in the hospital or at home for twenty-four
  to forty-eight hours. This is done to make sure that the patient
  does not have a more severe injury than was first thought. The
  doctor may ask a friend or relative of a patient sent home to wake
  them every few hours for the first thirty-six hours after the injury
  to make sure that they can return to full consciousness.
  
• Magnetic resonance imaging (MRI). This type of imaging study
  may be performed if the patient’s headaches and other symptoms
  are getting worse or have lasted a week or longer.
  

Treatment of mild concussion usually consists of a mild over-the-counter
pain reliever such as acetaminophen (Tylenol) or ibuprofen (Advil) plus
bed rest and extra fluids. Aspirin should be avoided because it increases
the risk of bleeding. If the patient has a bruise under the skin of the head
(a “goose egg”), ice wrapped in a washcloth can be applied to relieve the
swelling. Cuts in the skin may be treated in the doctor’s office with a
local anesthetic and stitches if necessary.
People injured in an athletic competition should not play again for at
least seven to ten days after the concussion.

Prognosis depends on the severity of the concussion. Most people heal
completely in one to two weeks, although healing may be somewhat
slower in adults over fifty-five. About 10 percent of patients develop what
is known as post-concussion syndrome (PCS). This is a condition
marked by persistent headaches for two weeks to several months after the
concussion. The patient may also have nausea and vomiting, or difficulty
reading or concentrating on their work. PCS usually goes away on its
own. If it persists after a few months, the patient will usually be referred
to a neurologist for further evaluation.
The effects of concussions tend to add up over time; it is known, for
example, that each concussion a person sustains makes it easier for them
to suffer another concussion in the future. Repeated concussions can lead
to permanent loss of memory and depression or other psychiatric disorders.
Professional athletes are particularly likely to suffer long-term injuries
from repeated concussions; several studies have found that the rate of
depression is three times higher and the risk of Alzheimer disease five
times higher in athletes who have had three or more concussions.

Not all accidents or other causes of concussions can be prevented. People
can, however, lower their risk of concussions by taking the following
safety measures:

• Sports: Athletes should wear protective headgear for such sports as
  martial arts, football, baseball, bicycling, motorcycling, rollerblading,
  and skateboarding. They should make sure their helmets
  and other protective gear are properly fitted. Coaches should insist
  that players are taught the rules of safe play and that they follow
  them. Last, players should report all head injuries to the team
  doctor even if they seem minor at the time.
  
• Workplace: People in occupations requiring hardhats should wear
  them at all times, particularly in construction work. Even a small
  object dropped from the upper floors of a building can cause a serious
  head injury.
  
• Home safety: Elderly persons or parents of small children should
  check their house or apartment for loose rugs, poor lighting, slippery
  floors, and other problems that increase the risk of falls—
  which are a common cause of concussions.
  

Concussions are likely to continue to be relatively commonplace
head injuries, particularly in victims of bicycle, motorcycle, and auto
accidents. Stricter regulations about allowing injured athletes to play,
however, may reduce the rate of concussions and their long-term consequences
in amateur as well as professional sports.