A concussion is a transient impairment of the brain function occurring due to a violent shake of the brain. A concussion is a function impairment, not a structural brain injury, therefore a CT scan will be normal. In the United States alone, sports injuries lead to 1.6-3.8 million concussions annually. In head to head collisions in football, a player’s head may experience G forces ranging from 100-190Gs. These forces and rapid deceleration speeds exerted on the brain are similar to being hit on the head with a sledge hammer. A sudden blow to the head leads to bouncing of the brain back and forth in the skull cavity. The shaking motion of the brain within the skull cavity may lead to a concussion.
Only 10% of concussions are associated with loss of consciousness (LOC). Therefore, LOC is not necessary to diagnose a concussion. Symptoms of concussions include: headache and dizziness (most common), confusion, imbalance LOC, vomiting, and convulsions or seizures. Other symptoms include:
- Slurred speech
- Feeling sluggish or foggy
- Double/blurry vision
- Light sensitivity
- Sensitivity to noise
- Decreased playing ability
When managing a concussion, one must first assess airway, breathing, and circulation. The cervical spine should also be assessed in case of an injury. Assessment of sensory and motor functions. Diagnosing a concussion depends on careful clinical examination and asking questions to assess the patient’s attention, memory, orientation, concentration, balance, and reaction time. When a concussion is diagnosed, the player must NOT return to play.
Concussion assessment tools such as the Standard Assessment of Concussion Test (SAC) or Immediate Post-Concussion Assessment and Cognitive Test (impact) may be used on the sidelines and at later follow-ups to assess the patient’s brain function and compare the pre-injury scores. It is worth noting that the SAC test does not include a neurologic exam and does NOT measure reaction time, coordination or balance. When concussion assessment tools are not available on the sidelines, the following questions can be used to quickly assess orientation, anterograde and retrograde amnesia, concentration, and the patient’s ability to recall word lists (adopted from the CDC with minor modifications):
- Ask the patient to repeat days of the week backwards
- What stadium are we in?
- Who scored last?
- What is the name of the opposing team?
- Retrograde Amnesia
- Do you remember the hit?
- What was the score prior to the hit?
- Anterograde Amnesia
- Choose any three words and ask the patient to repeat them
- Ability to recall word list
- Ask patient to recall the three words you asked earlier
It is worth noting that remote memory loss is more worrisome than recent memory loss. Patients who demonstrate any of the following signs and symptoms should be taken to the emergency room immediately: worsening headaches, repeated vomiting, seizures or convulsions, prolonged LOC, focal neurological sign, disorientation to time, place, and person, neck pain, increasing irritability and confusion, and upper or lower limb weakness or numbness. Red flags that may indicate the need to acquire head imaging such as CT scans include: A prolonged LOC, post-traumatic amnesia, persistently altered mental status, focal neurological deficits, and continued deterioration of clinical signs.
It is important to remember that the following are contraindications to return to play:
- Symptoms lasting more than 15 minutes
- Prior concussion within the same season
- Loss of consciousness
- Development of complications such as post-concussion syndrome
- Recurrence of symptoms on exertion
Complications include conditions such as second impact syndrome. Second impact syndrome occurs after sustaining a second head impact, even if minor, before achieving recovery from the first concussion may be potentially fatal. The mortality rate associated with second impact syndrome is approximately 50%. It occurs due to loss of autoregulation of the brain’s blood supply leading to vascular engorgement and herniation of the lower brain. Treatment usually consists of close observation, intubation, hyperventilating the patient and administration of IV osmotic diuretics.
Post-concussion syndrome occurs when persistent symptoms such as headaches, dizziness, and confusion lasting for weeks or even months after a concussion. Treatment is symptomatic and the patient will return to play is contraindicated. Epidural bleeding is associated with a lucid interval during which the patient feels find, followed by sever neurological decline. Seizure prophylaxis and surgical decompression are usually indicated. Cumulative effects may occur whether or not repetitive concussions have a cumulative effect remains a controversial topic.
Even though players may be eager to return to the game quickly, they must be advised to follow a stepwise strategy in order to achieve complete recovery and avoid potentially life threatening complications. The recovery strategy should include the following steps: a period of complete physical and mental rest until the symptoms subside. This should be followed by a return to light aerobic activities. Sports-specific training (still no contact). The recovery strategy should include non-contact drills and full-contact drills.