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| Patient Education -- Concussion |
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Concussion
Anyone who watches football on TV has seen incidences
of concussion. The player "had his bell rung," the announcer
will say flippantly after a particularly violent collision.
For years this casual attitude toward concussions was
common. Coaches and teammates would urge the injured player
to "shake it off" and return to the game after a brief
rest.
Fortunately, in the wake of premature retirements of star
athletes such as Steve Young after a series of concussions,
awareness of the potential seriousness of concussions
has risen. Concussions, even mild ones, are not a lighthearted
matter. Neurosurgeons and other brain injury experts emphasize
that although some concussions are less serious than others,
there is no such thing as a "minor concussion."
Prevalence of concussions
Concussions are a common occurrence in sports. More than
300,000 American athletes, most of them in high school
or college, sustain concussions or other mild to moderate
brain injuries each year, according to the Centers for
Disease Control (CDC).
Fully one-third of these brain injuries occurs in football.
Reasonable estimates find that from 4 to 20 percent of
college and high school football players will sustain
a brain injury over the course of one season. The risk
of concussion in football is three to six times higher
in players with a previous concussion.
Concussions also can occur in car accidents, bicycle mishaps
and in falls around the home, especially among toddlers
and the elderly. Because a concussion is a jarring of
the brain, a healthcare professional needs to be consulted
and proper period of rest is necessary. But in most cases
a single concussion should not cause permanent damage.
What is a Concussion?
A concussion is an injury to the brain, usually caused
by a blow to the head that results in temporary loss of
normal brain function. Most people assume that concussions
involve a loss of consciousness. Not true. In most cases,
the person with a concussion never loses consciousness.
The formal medical definition of concussion is: a clinical
syndrome characterized by immediate and transient alteration
in brain function including alteration of mental status
and level of consciousness, resulting from mechanical
force or trauma. Concussion means a change in mental status.
Those with concussions often cannot remember what happened
immediately before or after the injury. They may slur
their speech or exhibit confusion. Paramedics and football
trainers who suspect a concussion ask injured people what
year it is or direct them to count backward from ten in
an attempt to detect altered brain function.
A concussion can affect memory, judgment, reflexes and
muscle coordination. The speech and balance of the injured
person may also be impaired.
Confusion is a particular hallmark of concussion. The
three principal features of confusion are:
• Inability to maintain a coherent stream of thought
• A disturbance of vigilance with heightened distractibility
• Inability to carry out a sequence of goal-directed
movements
The specific symptoms of a concussion include: headache,
vision disturbance, dizziness, loss of balance, confusion,
memory loss, ringing ears, nausea and difficulty in concentrating.
If any of these occur after a blow to the head, a healthcare
professional should be consulted.
What is the exact cause of a concussion? The brain normally
floats inside the skull, cushioned gently by the surrounding
spinal fluid. The brain consists of a gelatin-like substance,
vulnerable to outside trauma. The skull protects the brain
against trauma but does not absorb the impact of a violent
force.
An abrupt blow to the head, or even a rapid deceleration,
can cause the brain to slosh inside the skull and bounce
against the inner wall of the skull. There is a potential
for tearing of blood vessels, pulling of nerve fibers
and bruising of the brain substance.
Sometimes the blow can result in microscopic damage to
the brain cells without obvious structural damage visible
on a CAT scan. This damage can lead to brain swelling.
Since the brain cannot escape the rigid confines of the
skull, severe swelling can compress the brain and its
blood vessels and limit the flow of blood. Without adequate
blood flow, the brain does not receive the necessary flow
of oxygen and glucose and can suffer a stroke. Brain swelling
after a concussion has the potential to amplify the severity
of the injury.
A blow to the head also can cause a more serious injury
to the brain. A contusion is a bruise of the brain involving
bleeding and swelling in the brain. A contusion visible
on a CAT scan often implies the brain underwent a greater
degree of force than a concussion.
A skull fracture occurs when the bone of the skull breaks.
Sometimes the broken skull bones cause bleeding or other
injuries by cutting into the brain or its coverings.
A hematoma is a blood clot that collects in or around
the brain. If active bleeding persists, hematomas can
rapidly enlarge. Like brain swelling, the increasing pressure
within the rigid confines of the skull due to an enlarging
blood clot can cause serious neurologic compromise and
even threaten a person''s life. A hematoma can be a surgical
emergency. Hematomas that are small can sometimes go undetected
initially but cause symptoms and require treatment several
weeks later. The warning signs of a serious brain injury
are:
• Lengthy period of unconsciousness
• Altered level of consciousness such as persistent
drowsiness
• Long-lasting confusion
• Convulsions
• Repeated vomiting
• Persistent nausea
• Dilated (enlarged) pupils
• Drainage of bloody or clear fluids from the ears
or nose
• Seizures
• Muscle weakness on one or both sides
• Walking and speaking abnormalities
• Unusual sleepiness
• Changes in behavior such as irritability
Seek medical help if these warning signs occur.
Three Grades of Concussion
There is no universal agreement on the grades of severity
for a concussion. There are at least 16 different guidelines
for concussion evaluation and return to play. Most guidelines
recognize three different grades of concussions and share
similar recommendations for return to play.
The two sets of guidelines most adhered to in the United
States were formulated by the American Academy of Neurology
and by Robert C. Cantu, MD, Chief, Neurosurgery Service,
and Director of Service of Sports Medicine, Emerson Hospital,
Concord, Massachusetts. Dr. Cantu has worked for more
than 30 years as a neurosurgeon and football team physician.
According to Dr. Cantu, a Grade 1 concussion involves
no loss of consciousness but the person suffers from impaired
intellectual function, especially in remembering recent
events and in assimilating and interpreting new information.
Grade 1 concussion occurs most frequently (more than 90
percent of concussions) and often escapes medical attention.
It is difficult for a physician on the sideline to recognize
the player has sustained a Grade 1 concussion. A teammate
often will notice the injured player may lose the snap
count or forget what play was called.
A Grade 2 concussion involves loss of consciousness for
less than five minutes or a period of post-traumatic amnesia
that lasts more than 30 minutes but less than 24 hours.
A Grade 3 concussion involves a loss of consciousness
longer than five minutes or post-traumatic amnesia that
lasts longer than 24 hours.
According to the American Academy of Neurology (AAN),
a Grade 1 concussion involves momentary confusion, no
loss of consciousness and the disappearance of concussion
symptoms or mental status abnormalities in less than 15
minutes.
A Grade 2 concussion involves momentary confusion, no
loss of consciousness and concussion symptoms or mental
status abnormalities that last more than 15 minutes. A
Grade 3 concussion involves a loss of consciousness, either
for a few seconds or much longer.
Treatment
The standard treatment for concussion is rest. For a headache,
acetaminophen (Tylenol) can be taken. Post-concussive
headaches are often resistant to stronger narcotic based
medications. Most one-time concussions are mild and result
in no long-term damage to the brain.
Post-concussion Syndrome
People who suffer a head injury may suffer from poor memory
and concentration, headache, fatigue and dizziness for
weeks or months. This is known as post-concussion syndrome.
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