A concussion is any type of traumatic brain injury that causes temporary dysfunction of the brain. Depending on the extent of the injury, victims may suffer from a variety of complications, from loss of consciousness to severe brain damage. Most concussions are mild and heal without surgery or medication.
Because many patients experience subtle symptoms that go unnoticed, it is important to seek immediate medical attention after any head injury.
Causes of Concussion
A concussion may be caused by a blow to the head or by violent shaking that causes the brain to collide with the inside of the skull. Any forceful impact can temporarily disrupt brain functions such as memory, consciousness and organized thought.
Because concussions are often caused by falls, people with mobility problems are at higher risk of sustaining this type of injury. Children are particularly susceptible due to poor balance during the early stages of their lives. People involved in high-impact sports, like football, are also at a high risk for concussion.
Concussions can also be caused by car accidents, violent assaults or fallen objects.
Concussion symptoms may be mild, moderate or severe. Two of the most common symptoms of concussion are amnesia and confusion.
Depending on the injury, patients may experience immediate symptoms, or symptoms may arise days or weeks later. Mild symptoms of concussion include:
- Headache or migraine
- Temporary memory loss
- Nausea or vomiting
- Ringing in the ears
Moderate to severe concussion symptoms can include:
- Dilation of pupils
- Temporary changes in vision, smell and taste
- Sensitivity to noise and light
- Mood changes
- Temporary loss of consciousness
- Changes in sleep patterns
Because most symptoms are subtle and go unnoticed, it is important to seek immediate medical attention following any traumatic brain injury.
The most significant complications associated with concussion are brain swelling and increased intracranial pressure (ICP). Brain swelling increases intracranial pressure, which can cause brain damage by destroying delicate brain tissue, as well as prevent vital blood and oxygen from circulating throughout the brain. If left untreated, increased intracranial pressure can be fatal.
As the brain swells, a concussion patient may feel increasingly drowsy or confused. Passing out and difficulty waking up can be signs of increased intracranial pressure and serious head injury.
In addition to brain swelling and increased intracranial pressure, many concussion patients experience post-concussion syndrome. Post-concussion syndrome can cause concussion symptoms to last for weeks or months after the incident. These symptoms can include:
- Persistent headache
- Mood changes
- Memory lapse
- Changes in vision or sense of smell
Though these symptoms can resolve over time, it is important to diagnose and treat them to avoid complications.
When a head injury patient seeks medical attention, a doctor will first address any life-threatening complications. Several neurological and physical evaluations will then be conducted to pinpoint the exact location of the injury and determine its severity.
Neurological evaluations generally consist of scans, including X-rays, computed tomography (CT) scans and magnetic resonance imaging (MRI) scans.
Doctors perform physical examinations to test vital signs, such as pulse and respiration. If a patient is demonstrating irregular breathing or heartbeat, he or she may be at risk of severe brain injury. During these evaluations doctors can also check for brain swelling or hemorrhaging.
While many concussion patients' loss of consciousness is temporary, it is very important to test for more severe brain damage. Consequently, as part of their physical examination doctors try to determine a patient's level of consciousness by checking his or her responses to stimuli. Two main "scales" are used to assess these responses: the Glasgow Coma Scale and the Rancho Los Amigos Coma Scale.
Most concussions heal without surgical intervention, though doctors recommend that concussion patients rest while their injury heals. Doctors also schedule frequent follow-up appointments with the patient to closely monitor the possibility of any complications.
For patients who are experiencing headaches or pain, doctors may recommend over-the-counter acetaminophen or ibuprofen, or a prescription pain-killer. It is important for concussion patients to avoid aspirin, as it may increase the risk of intracranial bleeding.
To learn more about traumatic brain injury and its classification, symptoms and treatments, please explore other articles on our site.
[Last revision: January 2010]