Traumatic brain injury (TBI), also known as intracranial injury, is a substantial head injury that results in damage to the brain. This damage can cause a wide spectrum of possible health outcomes.
TBI may also be caused by objects, such as bullets or a smashed piece of skull penetrating brain tissue. Causes of TBI also include falls, vehicle accidents and violence.
In this article, we will look at the causes, diagnosis, treatment, possible complications and prevention of TBI.
Contents of this article:
Fast facts on traumatic brain injury
Here are some key points about traumatic brain injury. More detail and supporting information is in the main article.
- The effect of a TBI can vary depending on the severity of the injury and where it occurs
- Around 1 in 3 injury-related deaths involve a TBI
- Roughly 2% of Americans live with a TBI-related disability
- The majority of TBIs are caused by falls
- TBI symptoms may include confusion, persistent headaches and sleeping problems
- If someone receives a head injury and experiences convulsions or slurred speech, they should seek urgent medical attention
- A concussion is classed as a mild TBI
- In America, TBI is the third most common injury to result from child abuse
- Blood pressure can severely drop after a head injury.
What is a TBI?
TBIs can be generated in a wide range of ways, from falls to collisions in sport.
TBI is generally the result of a sudden, violent blow or jolt to the head. The brain is launched into a collision course with the inside of the skull, resulting in possible bruising of the brain, tearing of nerve fibers and bleeding.
TBI severity varies enormously depending on which part of the brain is affected, whether it occurred in a specific location or over a widespread area, as well as the extent of the damage.
A head injury usually refers to a traumatic head injury, but is a broader category. Head injury may also involve damage to other structures (apart from the brain), such as the scalp or skull.
According to the Centers for Disease Control and Prevention (CDC):
- About one third of injury-related American deaths are linked to TBI
- About 230,000 hospitalizations occur annually in the US as a result of TBI
- 1.1 million Americans are treated for TBI and released from an emergency department
- Almost 2% of the US population lives with TBI-related disabilities
- About 2 million American adults and children suffer from TBI injury annually
- 50,000 patients die annually in the US as a result of TBI
- Every 15 seconds, one American man, woman or child sustains a significant TBI
- The total number of individuals with TBI who are not seen in an emergency department or receive any care is unknown
- Direct medical costs and indirect costs - such as lost productivity - of TBI totaled an estimated $60 billion in the US in 2000.
Among American children aged up to 14 years, TBI results in an estimated:
- 2,685 deaths
- 37,000 hospitalizations
- 435,000 emergency department visits annually.
Scientists have not managed, thus far, to identify effective medications to improve outcomes for such patients, despite the extent of the problem.
The CDC also reports that the main causes of TBI are falls (28%), motor vehicle traffic crashes (20%), struck by/against events (19%) and assaults (11%).
Symptoms of traumatic brain injury
TBI signs and symptoms may sometimes be subtle and might not appear for days or weeks after the injury. Some patients may look well, even though they may feel or behave differently.
Our brain controls our movements, thoughts, sensations and behaviors. A TBI can have several different physical and psychological effects. Initial physical effects are bruising and swelling. When injured brain tissue swells up pressure is increased; the injured brain tissue presses against the skull causing additional damage.
The most common signs and symptoms of TBI include:
- Fatigue (tiredness) and lethargy
- Getting lost easily
- Persistent headaches
- Persistent pain in the neck
- Slowness in thinking, speaking, reading or acting
- Moodiness - suddenly feeling sad or angry for no apparent reason
- Sleep pattern changes - this may include either sleeping much more or much or less than usual, or having trouble sleeping
- Light headedness, dizziness
- Becoming more easily distracted
- Increased photosensitivity (sensitivity to light)
- Increased sensitivity to sounds
- Loss of sense of smell or taste
- Tinnitus (ringing in the ears).
A child with a TBI may become irritable and listless.
Children - the same signs and symptoms as those listed above are possible. However, children typically are less likely to let others know how they feel. If a child has received a blow or jolt to the head and you notice any of the following signs or symptoms, call a doctor:
- Changes in sleeping patterns
- Irritability - the child does not stop crying and is hard to console, for example
- Loss of balance
- Loss of newly acquired skills (such as toilet training)
- Playing behavior changes
- Refusal to eat
- Loss of interest in their favorite activities or toys
- Unsteady walking
When to see a doctor - according to the Mayo Clinic, you should see a doctor if you suffered a blow to the head, and should seek emergency medical care if any of the following signs are present:
- Repeated vomiting
- Slurred speech
- Weakness or numbness in the arms or legs (hands and feet).
The Mayo Clinic also lists two types of signs or symptoms, depending on the severity of the TBI.
Mild TBI signs and symptoms (concussion) may include:
- A short period of unconsciousness
- Blurred vision, tinnitus (ringing in the ears), or a bad taste in the mouth
- Cannot remember events immediately before and after the injury took place
- Dizziness or loss of balance
- Memory problems
- Problems focusing mentally.
Moderate to severe TBI signs and symptoms may include:
- Agitation, confrontational
- Continuous headache
- Convulsion or seizures
- Coordination problems
- One or both pupils of the eyes are dilated
- Patient does not wake up from sleep
- Persistent nausea and/or vomiting
- Profound confusion
- Slurred speech
- Weakness and numbness in hands, feet, arms or legs.
On the next page, we look at the causes, diagnosis and treatment of TBIs.