Concussion
Traumatic brain injury can be devastating: it can severely impair normal brain functions. However, traumatic brain injury can also be very mild and may not cause severe or lasting brain damage. Mild traumatic brain injury is known as concussion. Concussion is temporary brain damage that disrupts normal brain function. Though concussion is minor and symptoms can be subtle, it is important to seek medical treatment to prevent complications and to rule out more serious brain injury.
Causes of Concussion
Concussion is caused by the head being struck or shaken violently, which causes the brain to collide with the inside of the boney skull. This temporarily disrupts normal brain functions. Disrupted brain functions include memory, consciousness, and organized thought.
People with mobility problems are at a higher risk for concussion, as they may fall, slip, or trip and sustain head injury. People involved in high impact sports or recreational activities are also at a high risk for concussion.
Children are also at a higher risk for concussion. As children learn to walk, they may fall and hit their heads. Children can also slip out of highchairs or injure themselves on furniture or playground equipment.
Other concussion causes can include car accidents, violence (blows to the head), and objects falling on the head.
Concussion Symptoms
Concussion symptoms may be mild, moderate, or severe. Common mild concussion symptoms can include headache or migraine, temporary memory loss, and nausea. Moderate to severe concussion symptoms can include dizziness, dilation of pupils, migraine, convulsions, and temporary changes in vision, smell, and taste. A person may also lose consciousness. Loss of consciousness is common but usually lasts for less than 30 minutes. If a person remains unconscious or dazed for more than 30 minutes, he or she may have more severe brain injury.
Additional symptoms of mild concussion may be subtle and go untreated. Any concussion symptoms should be evaluated by a doctor to avoid complications.
Concussion Complications
Concussion complications develop as a result of brain swelling and increased intracranial pressure. When injured, the brain swells and increases pressure within the skull. An increase of intracranial pressure is dangerous, as it destroys delicate brain tissue and prevents vital blood and oxygen from circulating throughout the brain.
As the brain swells, a person may feel increasingly drowsy or confused. If the person is difficult to awaken or begins to pass out, these can be signs of increased intracranial pressure and more serious brain injury. This complication can be fatal if left untreated.
Post-concussion syndrome is a common complication. Post-concussion syndrome symptoms include persistent headache, dizziness, mood changes, memory lapse (forgetfulness), and changes in vision or sense of smell. A person may also be depressed or irritable. Symptoms can begin weeks or even months after brain injury. Though these symptoms can resolve over time, it is important to diagnose and treat them to avoid complications.
Diagnosing Concussion
To diagnose concussion, doctors perform a complete physical and neurological evaluation. Doctors also use x-rays such as computed tomography scans (CT scans) and magnetic resonance imaging (MRI) to locate injury in the brain.
During a physical examination, a doctor tests vital signs such as pulse and respiration. If breathing is labored or heartbeat irregular, these may be signs of more severe brain injury.
Neurological examination involves evaluating memory, concentration, vision, coordination, balance, and reflexes. If a person is unconscious, doctors attempt to waken him or her with rigorous stimuli (such as nudging) and closely monitor the level of consciousness. If a person is unable to regain consciousness or fails to display conscious responses to neurological tests, more severe brain injury may be present.
X-rays and brain imaging help to locate injury in the brain and to evaluate any brain swelling or bleeding. CT scans and MRI's are used to locate the injury in the brain and to rule out or confirm complications.
Concussion Treatment
Concussion treatment involves closely monitoring a person's level of consciousness. A change in the conscious state can indicate more severe brain injury or developing brain swelling and increased intracranial pressure. The person may need to stay overnight in a hospital for observation.
Rest is important for treatment and recovery, and pain medication may be necessary for associated headaches. Before taking any medication, it is best to consult a doctor to ensure the condition is not worsening.
Traumatic brain injury may be mild, moderate, or severe. Concussion is a more mild form of traumatic brain injury. To learn more about the othertypes of traumatic brain injury and how they are diagnosed and treated, please read other articles on this site.
[Last revision: March 2007]