Minor head injury is common in sport. Many minor head injuries are concussions, defined by the Congress of Neurologic Surgeons as a clinical sundrome characaterized by immediate and transient post-traumatic impairment of neural function, such as alteration of consciousness, disturbance of vision and / or equilibrium due to brain stem involvement.
There are estimated to be about 300 000 concussions per year in contact sport in the USA
Between 1931 and 1986 there were 800 deaths due to head injury in North American Football
A recent study estimated the injury rate for concussion for a football player at 5.56 per 1000 games and 1.25 per 1000 practices.91
Minor head injuries may be more common than expected due to under-reporting. In a survey of University athletes, 70.4% of football players and 62.7% of soccor players had suffered a concussion. However, only 23.4% of the concussed football players and 19.8% of the concussed soccer players realized that they had suffered a concussion. Since the athletes did not recognize the symptoms, it is unlikely that these events were reported or attended to.112
Approximately 90% of sports related head injuries are classified as mild. Among overall hospitalizations for head injury in general, only 3% are sporting related.114
Multiple potential mechanisms include a direct blow to the head, injury to the jaw, sudden twisting of the head, or sudden deceleration of the head.
In concussion, there are usually no anatomically distinguishable lesions in the brain. Most symptoms likely represent a functional rather than structural injury.
Athletes may compain of feeling dazed, having their bell rung, memory difficulties, confusion, headache, nausea, disorientation, seeing stars, sleepiness, loss of vision, double vision, or feeling slow.
Post Traumatic Amnesia: This is represented by the length of time between trauma and the point when the athlete regains normal continuous memory function.
Disorientation: May be difficult to distinguish from PTA. Note that disorientation itself is not associated with memory loss.
Retrograde Amnesia: Inability to recount events occuring before the trauma. The length of retrograde amnesia usually shrinks over time.
Athletes may exhibit such features as poor coordination, altered balance, vomiting, slurred speech, slow response to questioning, poor concentration, inappropriate or labile emotions, personality changes, inappropriate behavior,
Transport to hospital, and consideration of imaging are indicated in the following circumstances:
Loss of consciousness more than five minutes.
Post traumatic seizure
Focal neurologic signs
Symptoms of cerebral irritation persisting for more than one hour.
Any deterioration in mental status.
More than one episode of moderate or severe concussion in one season.
There are various forms of neuropsychiatric investigation tools available.
CogSport: A computerized assessment tool has been shown to be a useful assessment tool. It is thought that measures of response speed, possible through the use of a computer, may be more useful than measurement of response accuracy. Psychomotor reaction speed may be the most sensitive index of cognitive changes.81
Biomechanical markers may be useful for the assessment of head injury. S-100B and Neuron -Specific Enolase (NSE) are the most frequently investigated. However, studies have shown that these markers are released not only in traumatic brain injuries, but also in non-cerebral injuries (fractures/surgery) and in healthy subjects during exercise such as boxing, running, hockey, or basketball.127
Above all, no athlete should be allowed to return to play until asymptomatic.
The Canadian Academy of Sport Medicine recommends that a player should not be allowed to return to the current game or practice if ANY symptoms or signs of concussion are present.
The player should be monitered for deterioration and should never be left alone.
The player should be evaluated by a medical doctor.
Return to play should be gradual.
Athletes should follow this orderly progression of return to play:
A period of absolute rest. The player does not proceed to step 2 until completely asymptomatic.
Light exercise such as walking or stationary cycling.
Sport specific activity (such as skating for Hockey Players)
Practice without body contact.
Practice with body contact.
Game Play.
Note that the athlete may not proceed to the next step until each step can be performed without any symptoms.
In general, no player should return to play until asymptomatic. Some authors feel that this should include a comprehensive assessment of physical examination, imaging studies, neuropsychological studies, balance testing, self-reported symptoms, and exertional tests.
Many injuries can be prevented by following some general rules for injury prevention
Mouthguards may theoretically help reduct concussion, although evidence is lacking.
Strengthening of neck muscles may prevent concussion.
Helmets are likely to reduce the frequency of major head injury, however, there effect on reduction of concussion is less well documented. Among a study hockey players, the rate of concussion was found to be four time higher among athletes without helmets when compared to those who wore full helmet and facial protection.113
Rule changes and coaching techniques are likely to be the most effective means to prevent concussion.
Post concussive syndrome may occur, with symptoms lasting weeks to months, although this is rare among athletes. Symptoms such as headache, dizziness, poor memory, poor concentration, and slow decision making may be present. These patients likely need cerebral imaging and neuropsychiatric testing.116
Grading of concussions is complex. There are MANY different grading scales currently available. Most are based on consensus decisions, but many do not reflect actual data, and return to play guidelines may not be scientifically validated.
One study showed that the presence of amnesia, particularly retrograde amnesia, appeared to predict the presence of symptoms and neurocognitive dysfunction. It appeared that brief disorientation (<5 min) was not predictive of future symptomatology, while prolonged disoriention of > 5min was predictive of postinjury memory and symptom deficit. This same study found that loss of consciousness did not predict symptoms or cognitive disorder. 115
The American Academy of Neurology grades concussions in the following Manner
|
Grade |
Symptoms |
Treatment |
|---|---|---|
|
I |
No loss of Consciousness, Transient confusion lasting less than 15 minutes |
Athlete is removed from the activity and examined immediately and each five minutes after. Athlete can return to the activity the same day if neurologic exam is normal after 15 minutes. A second Grade I concussion in the same day means out of activity until symptom free for one week. |
|
II |
No loss of consciousness, transient confusion lasting greater than 15 minutes |
Athlete removed from activity until symptom free for one week. If symptoms worsen, or persist for more than one week evaluation such as CT scan may be necessary. A grade II concussion following a Grade I on the same day means off activity until symptom free for 2 weeks |
|
II |
Loss of consciousness of any duration. |
An athlete who remains unconscious or has an abnormal neurological examination should be sent by ambulance to the emergency department. If CT scan shows abnormality, the athlete should be discouraged from ever returning to contact sports. Those who have a normal CT may return to sports in one week (for those who had brief loss of consciousness) or two weeks (for prolonged loss of consciousness) |