What Is a Concussion?
Concussions are traumatic head injuries that occur from both mild and severe blows to the head. Some head injuries may appear to be mild but research is finding that concussions can have serious, long-term effects, especially repeat head injuries or cumulative concussions.
A concussion is typically caused by a severe head trauma during which the brain moves violently within the skull. The brain cells all fire at once, much like a seizure. Some studies show that patients who suffer a concussion appear to have the brain activity of people in a coma.
A concussion may result from a fall in which the head strikes against an object or a moving object strikes the head. A suddenly induced turning movement such as a blow that twists the head (like a punch to the side of the face) is more likely to produce unconsciousness. However, significant jarring in any direction can produce unconsciousness.

The length of unconsciousness may relate to the severity of the concussion. Often athletes have no memory of events preceding the injury or immediately after regaining consciousness.
Concussion Signs and Symptoms

•    Confusion
•    Disorientation
•    Memory loss
•    Unconsciousness
•    Fluid draining from the ears, nose or mouth
•    Unequal size pupils

Concussion Linked to Depression
Depression is one of the many symptoms experienced by athletes following concussion. In fact, some research finds the prevalence of depression in head trauma patients can be as high as 40 percent. Several studies have also shown a link between a history of brain injury and a higher probability of developing major depression later in life.

•    One study on concussion in athletes from the Montreal Neurological Institute of McGill University identified a neurological basis of depression in athletes who have had concussions. Imaging tests done with functional MRI on athletes who had depression following a concussion showed the same pattern of brain activation as patients with major depression.

•    Another study found that of 2,552 retired pro-football players, over 11 percent of those with a history of multiple concussions also had a diagnosis of clinical depression. Players reporting three or more previous concussions were three times more likely to be diagnosed with depression than those with no history of concussion.

•    A study by researchers at the University of Illinois at Chicago College of Medicine reported finding structural changes in the white matter of the brains of patients with head injuries, with the most severe head injuries showing the most structural change. These structural changes correlate to cognitive deficits in thinking, memory and attention.

They also found that some mild head injuries caused damage only to the outer surface of the nerve (the myelin sheath of an axon), which may be able to be repaired, but more severe head injuries caused damage to the axon itself, which may not be as easily repaired. If an axon is severed, it is unlikely that it can repair itself.

Concussion in Skiing and Snowboarding
Research is also pointing to an increase in traumatic brain injury and spinal cord injuries among skiers and boarders largely due to higher speeds and more daring acrobatics on the slopes.
Canadian researchers found the occurrence rate of both spinal cord and traumatic brain injury appears to be increasing worldwide. Furthermore, they found that these increases in injuries coincide with an increase and acceptance of higher speeds on the slopes and more acrobatic maneuvers, such as jumping.

They also found that wearing a helmet can reduce the risk of head injury by up to 60 percent and highly recommend helmets for skiers and boarders.

What to Do If You Suffer a Head Injury During Sports
It is critical for anyone who plays a sport where a head injury is possible to know what to do for any head injury. If you suffer any head injury, stop playing and sit out the rest of the game. Even if you think it’s a mild bump on the head, you may have minor damage that can be repaired. If you return to play, you risk making that mild injury a permanent one.

Treatment of Concussion
If a head injury causes unconsciousness, immediate medical attention is required for evaluation of the injury. Most likely that player should not return to the sport for up to three months. Studies have shown that there is an increased rate of brain injury, depression and other serious effects from concussions. An initial baseline neurological evaluation by a physician will determines the appropriate treatment for an uncomplicated concussion.

Preventing Sports-Related Concussion
Because signs of a mild concussion -- confusion, disorientation and memory loss -- may disappear within minutes and may not be reported by the athlete, athletes are often allowed to continue playing or return to a game before their brain has had adequate time to heal.

According to researcher Mark Lowell, allowing an athlete to return to play too early increases their chance of more serious brain injury. Determining when it is safe for athletes to return to play is not easy, so researchers at the University of Pittsburgh's Sports Medicine Center developed a computer program called the Immediate Post-Concussion Assessment and Cognitive Testing system, or ImPACT, which measures an athlete's memory, reaction time and processing speed and helps make the return to play decision a bit more objective.

They test a player's baseline conditions at the start of a season and then retest any athlete who sustains a mild head injury or concussion. The results of the testing provide coaches and trainers with a more objective measure of whether the athlete is healthy enough to return to play. The ImPACT program is currently being used at high schools and colleges throughout the nation, as well as by the National Football League and National Hockey League.