Traumatic Brain Injury Fast Facts

A traumatic brain injury (TBI) is an injury that results from a blow to the head or a sudden, violent movement of the body. The injury may or may not involve penetration of the skull and direct damage to brain tissue.

Common causes of TBI are falls, car accidents, sports-related accidents, gun violence, combat injuries, and assaults.

A concussion is a relatively mild form of TBI.

Nearly 3 million Americans visit hospital emergency rooms each year as a result of traumatic brain injuries.

More than 800,000 American children suffer from traumatic brain injuries each year.

Severe TBIs can cause permanent neurological complications or death.

United Brain Association

Nearly 3 million Americans visit hospital emergency rooms each year as a result of traumatic brain injuries.

What is TBI?

A traumatic brain injury (TBI) is an injury to brain tissue usually caused by a blow to the head or by violent shaking or movement of the body. The brain may be injured even if the skull is not penetrated or broken, but in some cases, tissue damage is caused by the penetration of a foreign object (such as a bullet) or pieces of bone. A concussion is a form of TBI in which the brain moves violently inside the skull as a result of a blow or jolt to the head.

Symptoms of Traumatic Brain Injury

In the case of a mild concussion or less serious TBI, the symptoms produced by the injury may be temporary. Even a mild TBI requires immediate medical attention. In more severe injuries, the symptoms may be permanent, and complications may even be fatal. Some symptoms appear immediately or soon after the injury, and some other symptoms may emerge much later.

Mild TBI Symptoms

Common symptoms of mild TBI include:

  • Brief loss of consciousness (but loss of consciousness does not always occur)
  • Dizziness, disorientation, and/or confusion
  • Headache
  • Nausea and/or vomiting
  • Blurred vision, ringing in the ears, or other sensory problems
  • Sensitivity to light
  • Sleepiness, fatigue, or lethargy
  • Speech difficulties
  • Changes in sleep patterns
  • Memory loss
  • Difficulty focusing or concentrating
  • Mood or behavior changes
  • Anxiety or depression

Severe TBI Symptoms

The symptoms of moderate or severe TBI may look like those of mild TBI, but other symptoms may also emerge. These symptoms can include:

  • Prolonged loss of consciousness
  • Severe headache that is persistent or gets worse over time
  • Persistent nausea and vomiting
  • Prolonged dizziness, balance problems, or loss of coordination
  • Serious, persistent disorientation or confusion
  • Numbness, tingling, or weakness in the extremities
  • Seizures or convulsions
  • Dilated pupils or unequal pupil reactions
  • Persistent speech difficulties
  • Inability to stay awake
  • Extreme changes in mood or behavior, including agitation, anxiety, or combative anger
  • Clear fluid draining from the nose or ears

What Causes TBI?

Common causes of TBI include both accidental injuries and intentionally inflicted violence. Some causes are more common than others among certain demographic groups.

The most common causes of TBI include:

  • Falls. Accidental falls are the most common cause of TBI, with about half of all TBI cases being the result of a fall. Falls are most common among children and older adults. Falls account for about half of all TBIs in children under 18 and more than 80% of TBIs in adults over the age of 64.
  • Gunshot wounds. Intentional self-inflicted gunshot wounds accounted for 33% of all TBI-related deaths in the United States in 2014.
  • Vehicle accidents. Car crashes and other motor-vehicle-related incidents account for about 1 in 5 TBI-related hospitalizations.
  • Sports injuries. Injuries suffered while participating in sports such as soccer, football, baseball, lacrosse, skateboarding, and hockey are common causes of TBI in children and young people.
  • Violence. Domestic violence and child abuse are common causes of TBIs.
  • Combat injuries. TBIs caused by explosive devices are common among active-duty military personnel.

Is TBI Hereditary?

Traumatic brain injuries are caused by external events, so there is no direct connection between inherited traits and the causes of the injuries. However, scientists believe they may have identified a link between inherited genetic factors and the brain’s vulnerability to the effects of a traumatic brain injury and its ability to recover.

Several studies have examined a gene called the apolipoprotein E gene and how the gene plays a role in the brain’s response to traumatic brain injuries. The gene is vital in the production of a protein that seems to be involved in the maintenance and repair of neurons. The protein may be a key to the brain’s ability to recover from a TBI. Scientists don’t yet fully understand how the gene and its associated protein may aid recovery, but it is possible that this or another gene (or genes) may make a brain injuries more or less severe in certain individuals.

How Is TBI Detected?

Mild TBIs may go undetected because the initial, outwardly visible symptoms of the injury can be subtle. However, even mild TBIs can lead to permanent or even life-threatening complications, and early treatment is crucial in reducing the risk of those complications. It’s important to be alert for both immediate symptoms and those symptoms that might emerge some time after the initial injury.

Common immediate symptoms of a mild TBI include:

  • Headache
  • Confusion or mental fogginess
  • Dizziness or problems with balance
  • Loss of memory of the events surrounding the injury
  • Brief loss of consciousness (although this doesn’t happen with most mild TBIs)
  • Slurred speech
  • Nausea or vomiting
  • Light sensitivity or vision disturbances
  • Fatigue

You should seek immediate medical attention if you or someone close to you experiences any of these symptoms. You should also be watchful for symptoms that emerge or get worse in the hours or days after the injury. These symptoms can include:

  • Increased difficulty concentrating
  • More pronounced memory loss
  • Disruption in other senses, including hearing, taste and smell
  • Difficulty sleeping
  • Personality shifts or increased irritability

Traumatic Brain Injuries in Small Children

Falls and other accidents are common causes of TBI in children, but sometimes these incidents happen when adults are not watching. Small children may be unable to talk about their symptoms or tell adults what happened, so you should be alert to warning signs of TBI. These signs include:

  • Changes in eating or sleeping behavior
  • Walking or balance difficulties
  • Irritability or unusual crying
  • Apparent fatigue or loss of interest in playing

How Is TBI Diagnosed?

Doctors will take several steps in attempting to diagnose a TBI. In the case of a mild TBI, the diagnostic steps will typically begin with tests to see if symptoms are present. If these tests are positive or the symptoms are serious, further testing may be recommended.

  • Neurological exam. A doctor will perform an in-office exam that tests the patient’s neurological function. This exam will include tests of reflexes, balance, strength, coordination, vision, and hearing. The exam may also include tests of memory, concentration, and cognition.
  • Imaging tests. In cases where symptoms are severe or getting worse, a doctor may want to perform imaging tests to rule out a severe brain injury that has caused bleeding or swelling in the brain. These tests may include magnetic resonance imaging (MRI) or computerized tomography (CT) scans.
  • Hospitalization and observation. A doctor may recommend hospitalization or in-home observation, often for 24 hours after a mild TBI, to be sure that symptoms are not changing or getting worse.
  • Intercranial pressure monitoring. Swelling and fluid buildup can cause damaging pressure on brain tissue in the case of moderate or severe TBIs. Doctors may use a procedure to monitor pressure inside the skull to be alert for this life-threatening complication.


How Is TBI Treated?

The recommended treatment for TBI varies depending on the severity of the injury and the specifics of the damage to the brain.

Treat for Mild Traumatic Brain Injury

The mildest forms of TBI usually don’t require hospitalization, medications, or any treatment procedures. Unless symptoms suggest otherwise, at-home treatment for a mild TBI is likely to include:

  • Rest
  • Over-the-counter pain medications for headache
  • Close monitoring for new or worsening symptoms
  • Avoidance of electronic devices
  • Limitation of physical activities
  • Limitation of strenuous intellectual activity
  • Possible follow-up visits to the doctor

Treatment for Moderate or Severe Traumatic Brain Injury

Treatment for more severe TBIs will focus first on stabilizing the patient and managing any immediately life-threatening symptoms. Subsequent treatment steps will aim to manage any progressive symptoms and attempt to prevent serious complications.

Possible treatment steps may include:

  • Critical care to stabilize the patient’s vital functions (breathing, blood pressure and circulation, etc.)
  • Stabilization of the head and neck to prevent further injury
  • Medications to reduce swelling or fluid buildup in the brain and/or to control seizures
  • Sedation medications to decrease stress on the brain (also known as a medically-induced coma)
  • Surgery to remove blood clots on or near the brain
  • Surgery to stop bleeding in the brain
  • Surgery to repair skull fractures
  • Surgery to relieve pressure on brain tissues (sometimes involving removal of part of the skull)

Rehabilitation Therapies for Traumatic Brain Injuries

Depending on the severity and location of damage to the brain, a TBI patient may experience long-term complications that may be improved by rehabilitative therapies. Problems with movement, speech, cognitive function, memory, and behavior are common. Frequently used therapies include:

  • Physical therapy
  • Occupational therapy
  • Speech therapy
  • Psychotherapy
  • Family therapy
  • Vocational counseling

How Does TBI Progress?

TBIs can produce a wide range of complications that may be temporary, long-term, or permanent. Physical, cognitive, and behavioral complications are possible, and some complications may improve with treatment or therapy.

Physical Complications

Physical complications may occur in the immediate aftermath of a TBI, and some may develop during the recovery process. Some of the complications are potentially life-threatening. Possible complications include:

  • Seizures
  • Fluid buildup in and around the brain
  • Infections
  • Blood clots
  • Coma, minimally conscious state or persistent vegetative state
  • Chronic dizziness or balance problems
  • Chronic headaches
  • Facial paralysis
  • Hearing loss or ringing in the ears
  • Problems with vision, taste, or smell

Cognitive and Mental Function Complications

Complications that affect a TBI patient’s ability to think and function mentally can include:

  • Memory loss
  • Problems with concentration or attention
  • Problem-solving and decision-making difficulties
  • Impaired judgment
  • Trouble speaking or understanding speech
  • Trouble writing or understanding written language
  • Difficult interpreting nonverbal communication and/or understanding facial expressions
  • Mood swings, agitation, anger, or irritability
  • Increase in risk-taking behavior
  • Problems with impulse control or inappropriate behavior
  • Sleep disruptions
  • Depression and/or anxiety

How Is TBI Prevented?

The best strategy for avoiding traumatic brain injuries is avoiding the situations that put you or your loved ones at increased risk. That means following safety rules, avoiding especially risky situations, and taking precautions to prevent falls and accidents.

  • Always wear a seat belt and proper restraints in cars and motor vehicles.
  • Do not drive or operate any vehicle after you’ve been drinking or have used drugs, including prescription medications.
  • Follow gun safety rules, and avoid situations where guns are present. Do not allow children to have access to firearms.
  • Always wear properly fitted protective headgear when participating in any sport or recreational activity that carries a risk of head injury.
  • Do not let young children play sports unsupervised.
  • Install assistive devices such as handrails and grab bars in the homes of elderly loved ones or anyone who suffers from mobility or vision problems.
  • Remedy hazardous home situations such as cluttered stairways, loose rugs, and poorly lit spaces.

TBI Caregiver Tips

As you care for your loved one who has suffered a TBI, keep these basic ideas in mind:

  • Celebrate the victories. Recovery after a traumatic brain injury is a long and difficult road. Be prepared for stalls and setbacks along the way, and try to stay hopeful. Learn to recognize the beauty of small victories, and take time to celebrate each one.
  • Educate yourself and prepare for the future. Learn all you can about your loved one’s injury and the challenges they’ll face as they recover. Be realistic about expectations, and don’t be caught off guard by the hurdles you’ll face.
  • Don’t let TBI take over. The demands of caring for someone with a traumatic brain injury have a way of expanding to fill all the available space in your life. Don’t feel guilty for needing to take a break from caregiving now and then. Don’t neglect yourself or the rest of your family. Get help whenever you can, and don’t lose sight of your family’s needs beyond the injury.

TBI is often associated with other brain and mental health-related issues, a situation called co-morbidity. Here are a few of the disorders commonly associated with TBIs:

TBI Brain Science

Scientists are working to understand the ways that the brain recovers after a traumatic brain injury. TBIs cause not just physical damage to brain tissue, but also changes to the biochemical processes within and between brain cells. Some people recover from TBIs differently than others, and in many cases, the post-injury brain functions in a profoundly different manner that it did before the injury. A better understanding of these processes may help researchers develop more effective treatments that can prevent or reverse complications of TBIs.

Areas of current research include:

  • Associated neurological disorders. Research has suggested that TBIs, especially repetitive injuries, may increase the risk of degenerative neurological diseases such as Parkinson’s disease, Alzheimer’s disease, and other forms of dementia. Some scientists believe the connection could be because of TBI-related inflammation or abnormal protein buildup in the brain after an injury.
  • New treatments. Many studies are aimed at finding new treatments that may help patients to recover from TBIs. Potential treatment therapies include using low-frequency magnetic fields to stimulate recovery and the application of cell-repair-boosting antioxidant treatments.

TBI Research

Title: Neural Basis of Decision-Making Deficits in Traumatic Brain Injury

Stage: Recruiting

Contact: Leonardo G Cohen, MD

National Institute of Neurological Disorders and Stroke (NINDS)

Bethesda, MD 

Objectives: Deficits in decision-making are commonly found in individuals after traumatic brain injury (TBI) and can have a severe negative impact on quality of life. Converging evidence from both animal model and human studies suggest that decision-making deficits are linked with abnormal mesocorticolimbic network structure and function, and could potentially be mitigated through interventions that improve function within these neuronal circuits. The objectives of this protocol are to: (1) quantify differences in performance on a decision-making task between TBI patients and healthy volunteers; (2) determine whether baseline features of mesocorticolimbic network structure and function predict subsequent decision-making performance in both TBI patients and healthy volunteers; and (3) determine if facilitatory transcranial direct current stimulation (tDCS) applied over the dorsolateral prefrontal cortex (dlPFC), a mesocorticolimbic network region crucially involved in decision-making, improves decision-making after TBI.

Study Population: Up to 40 healthy adult volunteers and 40 TBI patients will be recruited under the protocol to participate in up to two experiments.


Title: Exercise and Rehabilitation After Traumatic Brain Injury

Stage: Recruiting

Principal investigator: Grace S Griesbach, PhD

Centre for Neuro Skills

Encino, CA

Exercise-based therapies can promote recovery of function and are easily implemented in the clinical rehabilitation setting. This study will determine if exercise facilitates recovery by improving markers of neuroplasticity and decreasing neuroinflammatory responses. The investigators will also determine if variations in genes involved in neuroplasticity, memory and inflammation influence the responsiveness to exercise and rehabilitation. Particular genetic polymorphisms involved in neuroplasticity and inflammatory responses will be evaluated. Recovery will be determined by assessing cognitive function, life quality and balance.


Title: Buspirone for the Treatment of Traumatic Brain Injury (TBI) Irritability and Aggression

Stage: Recruiting

Principal Investigator:  Flora Hammond, MD  

Indiana University/Rehabilitation Hospital of Indiana

Indianapolis, IN

PURPOSE OF PROJECT: To study the effect expressed by persons with TBI through assessment of buspirone effectiveness for post-traumatic irritability and aggression and development of an irritability/aggression impact measure.

SUMMARY OF PROJECT: It is anticipated that 74 subjects with 74 corresponding subject observers will be recruited for the treatment study. Subjects will be recruited from community and self-referrals.

Interested potential participants will be scheduled for an in-person screening visit. Subjects who consent and qualify will be randomized in a 1:1 ratio, buspirone or placebo. Stratification to randomization group will occur based on the presence of major or minor depression (defined by PHQ-9 total score >5). Randomized subjects will receive active treatment or placebo. There will be 4 clinic visits. Visits will occur at baseline, for consenting and screening, day 35, day 63 and day 91. At all 4 clinic visits, both the subject and the observer will be given questionnaires regarding the subject’s behavior and mood. Day 91 ends the period of the randomized clinical trial phase of the study and the subjects will begin the 1 month continuation phase of the study in which all participants receive active buspirone.

The following questionnaires will be used as measures of irritability and aggression for the subject and the observer: Neuropsychiatric Inventory (NPI & NPI-Distress), Aggression & Irritability Impact Measure (AIIM) and Global Impression of Change.

The following questionnaires will be dispensed to the subject only: TBI-Quality of Life-Anger, Personal Health Questionnaire (PHQ-9), Generalized Anxiety Disorder (GAD-7), PTSD Checklist Civilian (PCL-C), and Glasgow Outcome Scale Extended (GOS-E) The Investigator will complete the Clinical Global Impression of change at Visits 1, 2, 3, and 4. History and Physical Exam, creatinine level (kidney function) and liver function tests will be obtained for eligibility. Serum pregnancy tests will be drawn at screening for females of childbearing potential.

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