Traumatic Brain Injury
Traumatic brain injury (TBI) is a sudden injury from an external force that affects the functioning of the brain. It can be caused by a bump or blow to the head (closed head injury) or by an object penetrating the skull (called a penetrating injury).
The most common form of TBI is concussion. A concussion can happen when the head or body is moved back and forth quickly, such as during a motor vehicle accident or sports injury.
Concussions are often called "mild TBI" because they are usually not life threatening. However, they still can cause serious problems, and research suggests that repeated concussions can be particularly dangerous.
A person who has a TBI may have some of the same symptoms as a person who has a non-traumatic brain injury. Unlike TBI, this type of injury is not caused by an external force, but is caused by an internal problem, such as a stroke or infection.
Both types of injury can have serious, long-term effects on a person's cognition and functioning.
TBI symptoms vary depending on the extent of the injury and the area of the brain affected. Some symptoms appear immediately; others may appear several days or even weeks later. A person with TBI may or may not lose consciousness—loss of consciousness is not always a sign of severe TBI.
Symptoms of Mild TBI
A person with a mild TBI may experience:
- Blurred vision
- Ringing in the ears
- Tiredness or sleepiness
- A bad taste in the mouth
- A change in sleep habits
- Behavior or mood changes
- Trouble with memory, concentration, attention, or thinking
- Loss of consciousness lasting a few seconds to minutes1
- Sensitivity to light or sound
- Nausea or vomiting
Symptoms of Moderate or Severe TBI
A person with moderate or severe TBI may have some of the symptoms listed above. In addition, the person may experience any of the following:
- Headache that gets worse or won’t go away
- Repeated vomiting or nausea
- Slurred speech
- Convulsions or seizures
- An inability to wake up from sleep
- Enlargement of the pupil (dark center) of one or both eyes
- Numbness or tingling of arms or legs
- Loss of coordination
- Increased confusion, restlessness, or agitation
- Loss of consciousness lasting a few minutes to hours
A person who suffers a blow to the head or another trauma that may have caused a TBI should seek medical attention.
Treatment for severe TBI
In most cases, emergency care focuses on stabilizing the patient and promoting survival. This care may include ensuring adequate oxygen flow to the brain, controlling blood pressure, and preventing further injury to the head or neck.3 Once the patient is stable, other types of care for TBI and its effects can begin.
Surgery may be needed as part of emergency care to reduce additional damage to the brain tissues. Surgery may include:
- Removing clotted blood. Bleeding in the brain or between the brain and skull can lead to large areas of clotted blood, sometimes called hematomas (pronounced hee-ma-TOH-muhz), that put pressure on the brain and damage brain tissues.
- Repairing skull fractures. Setting severe skull fractures or removing pieces of skull or other debris from the brain can help start the healing process of the skull and surrounding tissues.
- Relieving pressure in the skull. Making a hole in the skull or adding a shunt or drain can relieve pressure inside the skull and allow excess fluid to drain.
NIH: National Institute of Neurological Disorders and Stroke