Traumatic brain injury (TBI), a form of acquired brain injury, occurs when a sudden trauma causes damage to the brain. The damage can be focal - confined to one area of the brain - or diffuse - involving more than one area of the brain. TBI can result from a closed head injury* or a penetratinghead injury. A closed injury occurs when the head suddenly and violently hits an object but the object does not break through the skull. A penetrating injury occurs when an object pierces the skull and enters brain tissue.
TBI is a major public health problem, especially among male adolescents and young adults ages 15 to 24, and among elderly people of both sexes 75 years and older. Children aged 5 and younger are also at high risk for TBI.
TBI costs the country (USA) more than $56 billion a year, and more than 5 million Americans alive today have had a TBI resulting in a permanent need for help in performing daily activities. Survivors of TBI are often left with significant cognitive, behavioral, and communicative disabilities, and some patients develop long-term medical complications, such as epilepsy.
Other statistics dramatically tell the story of head injury in the United States. Each year:
• approximately 1.4 million people experience a TBI,
• approximately 50,000 people die from head injury,
• approximately 1 million head-injured people are treated in hospital emergency rooms, and
• approximately 230,000 people are hospitalized for TBI and survive.
What Are the Different Types of TBI?
Concussion is the most minor and the most common type of TBI. Technically, a concussion is a short loss of consciousness in response to a head injury, but in common language the term has come to mean any minor injury to the head or brain.
Other injuries are more severe. As the first line of defense, the skull is particularly vulnerable to injury. Skull fractures occur when the bone of the skull cracks or breaks. A depressed skull fracture occurs when pieces of the broken skull press into the tissue of the brain. A penetrating skull fracture occurs when something pierces the skull, such as a bullet, leaving a distinct and localized injury to brain tissue.
Skull fractures can cause bruising of brain tissue called a contusion. A contusion is a distinct area of swollen brain tissue mixed with blood released from broken blood vessels. A contusion can also occur in response to shaking of the brain back and forth within the confines of the skull, an injury called “contrecoup”. This injury often occurs in car accidents after high-speed stops and in shaken baby syndrome, a severe form of head injury that occurs when a baby is shaken forcibly enough to cause the brain to bounce against the skull. In addition, contrecoup can cause diffuse axonal injury , also called shearing , which involves damage to individual nerve cells ( neurons ) and loss of connections among neurons. This can lead to a breakdown of overall communication among neurons in the brain.
Damage to a major blood vessel in the head can cause a hematoma, or heavy bleeding into or around the brain. Three types of hematomas can cause brain damage. An epidural hematoma involves bleeding into the area between the skull and the dura. With a subdural hematoma , bleeding is confined to the area between the dura and the arachnoid membrane . Bleeding within the brain itself is called intracerebral hematoma.
Another insult to the brain that can cause injury is anoxia. Anoxia is a condition in which there is an absence of oxygen supply to an organ's tissues, even if there is adequate blood flow to the tissue. Hypoxia refers to a decrease in oxygen supply rather than a complete absence of oxygen. Without oxygen, the cells of the brain die within several minutes. This type of injury is often seen in neardrowning victims, in heart attack patients, or in people who suffer significant blood loss from other injuries that decrease blood flow to the brain.
Symptoms of a TBI can be mild, moderate, or severe, depending on the extent of the damage to the brain. Some symptoms are evident immediately, while others do not surface until several days or weeks after the injury. A person with a mild TBI may remain conscious or may experience a loss of consciousness for a few seconds or minutes. The person may also feel dazed or not like himself for several days or weeks after the initial injury. Other symptoms of mild TBI include:
• blurred vision or tired eyes
• ringing in the ears
• bad taste in the mouth
• fatigue or lethargy
• a change in sleep patterns
• behavioral or mood changes, and
• trouble with memory, concentration, attention, or thinking.
A person with a moderate or severe TBI may show these same symptoms, but may also have
• a headache that gets worse or does not go away
• repeated vomiting or nausea
• convulsions or seizures
• inability to awaken from sleep
• dilation of one or both pupils of the eyes
• slurred speech
• weakness or numbness in the extremities
• loss of coordination, and/or
• increased confusion, restlessness, or agitation.
Small children with moderate to severe TBI may show some of these signs as well as signs specific to young children, such as
• persistent crying
• inability to be consoled, and/or
• refusal to nurse or eat.
Anyone with signs of moderate or severe TBI should receive medical attention as soon as possible.
Half of all TBIs are due to transportation accidents involving automobiles, motorcycles, bicycles, and pedestrians. These accidents are the major cause of TBI in people under age 75. For those 75 and older, falls cause the majority of TBIs. Approximately 20 percent of TBIs are due to violence, such as firearm assaults and child abuse, and about 3 percent are due to sports injuries. Fully half of TBI incidents involve alcohol use.
The cause of the TBI plays a role in determining the patient's outcome. For example, approximately 91 percent of firearm TBIs (two-thirds of which may be suicidal in intent) result in death, while only 11 percent of TBIs from falls result in death.
Unlike most neurological disorders, head injuries can be prevented. The Centers for Disease Control and Prevention (CDC) have issued the following safety tips for reducing the risk of suffering a TBI.
• Wear a seatbelt every time you drive or ride in a car.
• Buckle your child into a child safety seat, booster seat, or seatbelt (depending on the child's age) every time the child rides in a car.
• Wear a helmet and make sure your children wear helmets when
• riding a bike or motorcycle;
• playing a contact sport such as football or ice hockey;
• using in-line skates or riding a skateboard;
• batting and running bases in baseball or softball;
• riding a horse;
• skiing or snowboarding.
• Keep firearms and bullets stored in a locked cabinet when not in use.
• Avoid falls by
• using a step-stool with a grab bar to reach objects on high shelves;
• installing handrails on stairways;
• installing window guards to keep young children from falling out of open windows;
• using safety gates at the top and bottom of stairs when young children are around.
• Make sure the surface on your child's playground is made of shock-absorbing material (e.g., hardwood mulch, sand).
There are a few different ways to categorize traumatic brain injuries. They can be grouped based on whether the injury is open or closed, whether the injury is located in a small, specific area, known as a focal injury, or occurring over a large area, called a diffuse injury. A third way to classify the brain injury is based on how severe the injury is.
A closed injury can occur when the head hits or is hit by an object, but the object does not break through the skull or protective covering of the brain. An open, or penetrating injury occurs when an object does break through the skull and the brain’s protective coverings.
How severe a TBI is, is based on the following three things:
• Loss of consciousness
• Loss of memory, and
• The Glasgow Coma Scale Score (see below)
The Glasgow Coma Scale scores a person’s eye opening abilities, verbal responses and motor responses.
A mild Traumatic Brain Injury, or concussion, may cause a loss of consciousness or a loss of memory. A brain injury is classified as mild TBI or concussion when the patient experiences:
• A loss of consciousness, if any, lasting for less than 30 minutes
• Memory loss after the traumatic event, called post-traumatic amnesia or PTA, that lasts for less than 24 hours
• A Glasgow Coma Score of 13 – 15
A brain injury is classified as Moderate TBI when the patient has:
• A loss of consciousness that lasts for more than 30 minutes but less than 24 hours
• Post-traumatic amnesia lasting for 24 hours to 7 days, or
• A Glasgow Coma Score of 9 – 12
Patients with moderate TBI usually make a good recovery with treatment or learn to manage any problems that result from the injury.
A brain injury is classified as Severe TBI when the patient has:
• A loss of consciousness that lasts for more than 24 hours
• Post-traumatic amnesia lasting for 7 days or longer, or
• A Glasgow Coma Score of 8 or less, which indicates that the patient is in a coma
Severe TBI is often caused by crushing blows or penetrating wounds to the head. These injuries can severely damage the brain. In many cases, it’s not possible to recover completely from a severe TBI.
After a traumatic event, life-threatening injuries will be taken care of, and the medical team will look for signs of TBI. A key part of that diagnosis and treatment involves determining how badly the brain is injured.
When a patient loses consciousness, the amount of time that they’re unconscious is important in determining the extent of the brain injury. Usually, the longer the loss of consciousness, the more severe the injury.
When the patient is conscious, a series of questions may be asked to determine their mental state. Questions such as “what is your name?”, “what is today’s date?”, and “do you know where you are?” can be asked to help determine if the patient is confused. The patient may also be asked to perform simple movements such as holding up a specific number of fingers or moving their limbs in order to determine if they can move and understand what is happening around them.
When possible, a detailed medical history is taken. Getting information about other injuries or accidents is important, and sometimes patients don’t mention these. Reasons for this can include:
• Some patients may not consider the injury serious because they were told the condition was mild or just a "bump on the head"
• Some patients may not realize that they received a brain injury because they were briefly unconscious when it happened
• Some patients may be focused on a more severe injury that occurred at the same time
• Some may be too embarrassed to mention certain symptoms, such as memory problems or feeling dazed
Another key step in the diagnosis of TBI is a thorough examination of nervous system function, called a neurological exam. Imaging tests of the head such as MRIs, and CT scans can show broken bones, bleeding, swelling, and other injuries.
Unfortunately, these imaging tests are not always available, especially in combat situations. Also, the signs of traumatic brain injury may not appear on these scans. Some more advanced tests, such as PET scans and DTI scans, can give the medical team more information on the injury.
It’s important to know that patients with metal objects in their body may not be able to have some tests such as MRI’s.
Neuroradiological tests using computer-assisted brain scans can help doctors visualize damage to the brain. These tests can include:
The most common imaging test is computerized axial tomography, called a CT or CAT scan. This scan produces an x-ray that shows a cross-sectional image of the brain. CT scans can detect physical changes in the brain such as hematomas and swelling, which may require immediate treatment.
Another useful diagnostic test is magnetic resonance imaging, or MRI, which uses a large magnet and radio waves to generate computerized images of the brain without exposing the patient to x-ray radiation. MRIs produce high-resolution images of brain structures and are painless.
Depending on individual circumstances, a variety of other diagnostic tools and techniques may be employed. These include the following:
An angiogram is a test used to examine blood vessels in the brain. It involves injecting dye into an artery that supplies blood to the brain, usually through a catheter inserted in the groin. The dye outlines the blood vessels, enhancing the view on the x-ray.
An ICP monitor is a device used to measure intracranial pressure, or pressure within the brain. It consists of a small tube, placed into or on top of the brain through a small hole in the skull, connected to a transducer that registers the pressure.
An EEG, or electroencephalograph, is a test to measure electrical activity in the brain. It uses electrodes, in the form of patches, applied to the head.
X-rays, MRIs, and CT scans can detect fractures, hemorrhages, swelling, and certain kinds of tissue damage, but they do not always detect traumatic brain injury. This is because TBI, especially in its milder forms, often involves subtle traumas to the brain that cause chemical and physical changes to brain tissues. These changes often cannot be found with standard imaging procedures. More sophisticated imaging techniques that measure brain cell metabolism, such as single-photon emission computed tomography, called SPECT, positron emission tomography, called PET, or diffusion tensor imaging, called DTI, can help diagnose these milder injuries, but rarely change the treatment plan.
Single-photon emission computed tomography, or SPECT, is a procedure in which a gamma camera rotates around the patient and takes pictures from many angles, which a computer then uses to form a cross-sectional image.
Positron emission tomography, or PET, is a specialized imaging technique that uses short-lived radioactive substances to produce three-dimensional colored images. PET scanning provides information about the body's chemistry not available through other procedures. Unlike other imaging techniques that look at anatomy or body form, PET studies metabolic activity or body function of substances functioning within the body.
Diffusion tensor imaging, or DTI, is a specialized type of MRI that measures the movement of fluid in the brain, detecting areas where the normal flow of fluid is disrupted.
Glasgow Coma Scale
The Glasgow Coma Scale is used as a preliminary evaluation tool to gauge the severity of a TBI. It measures post-trauma eye opening abilities, verbal responses and motor responses, assigning each area a score. The scores from each section are then added together for a total score. The lower the score the worse the initial traumatic brain injury.
Glasgow Coma Scale
Eye Opening (E)
To speech 3
To pain 2
No response 1
Best Motor Response (M)
To verbal command: obeys 6
To painful stimulus: localizes pain 5
No response 1
Best Verbal Response (V)
Oriented and converses 5
Disoriented and converses 4
Inappropriate words 3
Incomprehensible sounds 2
No response 1
Score: Eye score (E) + Motor score (M) + Verbal score (V) = 3 to 15
Secondary complications - Intracranial pressure
Secondary complications are conditions that develop over a period of hours to days after the traumatic brain injury occurs. Increased intracranial pressure is one example of a secondary complication.
It’s common for swelling and fluid build-up to occur after any part of the body is injured. In some cases, when the brain is injured, swelling occurs and fluid builds up inside the skull, or cranium. This is serious because there is no place for swollen tissues to expand and no adjoining tissues to absorb excess fluid. The higher pressure caused by the swelling of the brain inside the skull is referred to as increased intracranial pressure.
Medical personnel measure a patient’s intracranial pressure, or ICP, using a probe or catheter. The instrument is inserted into the brain through a hole drilled into the skull, and is connected to a monitor that registers the patient's ICP.
Secondary complications - Hypoxia
Hypoxia is the lack of oxygen to any tissue or organ in the body. Cerebral hypoxia refers to a condition where there is a decrease of oxygen supply to the brain, even if there is normal blood flow.
Symptoms of mild cerebral hypoxia include inattentiveness, poor judgment, memory loss, and a decrease in motor coordination. Prolonged hypoxia can cause coma, seizures, and even brain death.
Hypoxia is a possible secondary complication that can develop over a period of hours to days after the initial TBI.
Secondary complications - Anoxia
Anoxia is the complete lack of oxygen to any tissue or organ in the body. Anoxic brain injury is when the brain is deprived of oxygen and blood flow, causing damage to the brain cells. The longer an individual goes without oxygen to the brain, the more damage occurs. Brain cells are extremely sensitive to oxygen deprivation and can begin to die within five minutes after the oxygen supply has been cut off. This can lead to permanent brain damage. For this reason, first responders are trying to administer oxygen as quickly as possible following an injury.
Secondary complications - Hypotension
Hypotension is defined as blood pressure that is below the normal expected for an individual in a given environment. Hypotension is the opposite of hypertension, which is abnormally high blood pressure.
When blood pressure drops below a certain level, oxygen and other nutrients are not efficiently delivered to the brain. This can lead to dizziness and fainting or be an indication of other serious conditions. Severely low blood pressure can lead to a life-threatening condition called shock.
For many patients, the damage to the brain resulting from TBI may lead to life long disabilities. The term disability in relationship to TBI means a loss of physical or mental function caused by damage to the brain. Keep in mind that many patients with TBI will be suffering from other serious injuries that happened at the same time as their brain injury. One of the greatest challenges for the patient is working to recover from the brain injury while they are recovering from other physical injuries. Even patients who appear to recover fully may have some long-term symptoms. Challenges with work and completing tasks that were once routine can be much more difficult than before the injury. Some patients find that the skills and abilities that they used before the injury to meet these challenges are not as sharp as they once were.
These ongoing challenges can also affect the patient’s personal life. People who have experienced brain injuries may take longer to do simple things such as coming up with the correct change in the checkout line at the grocery store or placing an order at a restaurant. Family relationships will almost certainly change and in some cases the patient will be totally dependent on their caregivers.
Despite the advances in early diagnosis and treatment of moderate to severe TBI, the fact remains that traumatic brain injury will be a life-changing experience for many patients. Helping the patient, family members, and caregivers cope with these long-term consequences is an important part of TBI rehabilitation.
Examples of disabilities, or the loss of physical or mental function caused by damage to the brain from TBI are:
• Problems walking
• Difficulty carrying or moving objects
• Vision problems
• Loss of fine motor skills, such as typing
• Inability to recognize something based on touch
• Difficulty thinking and remembering, or
• Difficulty with social relationships
Other challenges that a TBI patient may experience are:
• Difficulty making and keeping personal and professional relationships
• Difficulty being part of social activities
• Difficulty with recreational activities, or
• The decreased ability or inability to keep a job
During the rehabilitation and transition phases of TBI treatment, members of the healthcare team will provide information to the patient and family members about dealing with these issues. Specific tools and coping strategies will be suggested, for example, writing a detailed list of steps needed to complete a task, using prompts or visual aids to help remember things, or using assistive devices to move around, such as a walker or a wheelchair. Learning new ways to do things is a very important part of recovery.
The treatment of TBI often includes four stages: immediate, intermediate, rehabilitation, and transitional. The treatment in each stage will depend on how bad the brain injury is and the physical condition of the patient at each stage. If the injury is detected and treated early, most patients will have improvement in brain function and return to some level of a productive life.
It’s important to know that each patient will recover at their own pace and to different degrees, depending on the number and type of injuries.
Immediate treatment is designed to take care of any life-threatening injuries right after the trauma, providing the first line of care for the patient. Rescue or emergency personnel work to unblock airways, help with breathing, and keep blood circulating. They work to administer oxygen as quickly as possible after the injury to help reduce the risk of additional damage to the brain. Cardiopulmonary resuscitation, or CPR, may also be necessary. Steps are taken to control blood loss, replace lost blood with fluids, and prevent or treat other complications.
Immediate treatment continues when the patient arrives at a medical facility. Since the normal pressure inside the skull may increase after an injury, one important step taken is to measure that pressure. This pressure is known as intracranial pressure, or ICP. Because the increase in ICP can be dangerous, it needs to be closely watched using an ICP monitor.
In some cases of moderate to severe TBI, surgery may be needed to reduce the intracranial pressure and provide space for any swelling of the brain. There are two kinds of surgery that are often used to do this. One of these involves the temporary removal of part of the skull, in the form of a bone flap. This procedure is called a craniotomy. The brain can then be accessed for treatment, pressure on the brain is relieved, and the bone flap is replaced.
If the bone is not replaced immediately, the procedure is called a craniectomy. In this case, the original bone may be replaced at a later time, or an artificial replacement, made specifically for the patient, may be used. While the bone flap is not in place, many patients wear a helmet to protect their brain.
Seizures can occur seconds, weeks, or years after a TBI. A seizure can be a minor twitching of one finger, arm or leg, or a complete loss of consciousness with uncontrolled shaking of the entire body. Seizures can be particularly dangerous during the immediate and intermediate phases of treatment. For this reason, most patients with moderate to severe TBI receive anti-seizure medication for at least a week after the injury.
Another important part of both immediate and intermediate care is the prevention of other medical problems that can happen along with the brain injury. One concern is that the patient’s blood chemistry can become unbalanced, making confusion worse and possibly causing seizures. Another concern is that patients can get infections that can be very serious. Medications and other therapies can be used to treat or control these conditions.
Treating Intracranial Pressure
During the immediate and intermediate phases of TBI treatment, swelling in the brain is closely monitored and treated when necessary. Brain swelling is a serious problem. It causes increased pressure on the brain tissue which can be easily damaged. Because the skull is hard, increased intracranial pressure can compress or squeeze the soft brain tissue against it, keeping blood from flowing to the brain tissue and causing damage to brain cells.
To help with this condition, an intracranial pressure, or ICP monitor can be inserted through the skull to give the medical team a constant measurement of the pressure. If the ICP rises too high, medications are given to reduce the pressure, slow brain function down, and increase blood flow to the injured part of the brain. The patient also can be placed on a breathing machine, known as a ventilator.
If the ICP monitor shows that intracranial pressure is building to a dangerous level, steps are taken to reduce the pressure. This can be done by draining fluid from the brain using a catheter that’s already in place, or with other surgical procedures.
When brain swelling is severe, increased pressure can be reduced by surgically removing part of the skull, which will later be replaced. This allows swollen tissues to expand, reducing the risk for additional damage to the brain.
Intermediate TBI Treatment
Intermediate treatment is provided after the patient’s immediate medical needs have been met. The main goals of intermediate treatment include:
• Finding and treating complications as soon as possible
• Evaluating and planning for recovery
• Preventing additional injuries, and
• Preparing for rehabilitation, if necessary
In terms of the early detection of complications, the medical team is on the lookout for bedsores, muscle contractions, infections, and other complications, such as fluid build-up in the brain, that may need surgery.
Evaluation and planning for recovery involves a specialized team that may include physicians, nurses, physical therapists, occupational and speech therapists, neuropsychologists, neurologists, social workers and others. These professionals help patients and their families to understand medical conditions and disabilities, and to develop a realistic recovery plan.
Often patients with TBI have continuing memory loss, called post-traumatic amnesia, or PTA. In addition to PTA, these patients often have problems with their attention span, and they may have an increased risk for other injuries due to lack of coordination, poor balance, and weakness. These patients may also have poor self-control and try to do things that they are not able to do, such as climb out of bed or walk by themselves when it is dangerous to do so. Because of this, preventing more injuries from occurring is an important part of intermediate treatment.
The goal is to help the patient return to normal everyday life in as many ways as possible, making up for lost abilities using new tools. This is sometimes called “cognitive retraining.” For those who can, getting back to work or school is often a major goal in their rehabilitation plan. For some TBI survivors, this is not a realistic goal.
Patients with moderate to severe TBI often have long-term medical problems that require specialized attention. Some common problems and their treatments are:
• Abnormal and spastic muscle tone can sometimes be treated with physical therapy, medication, or minor surgery
• Chronic pain can sometimes be treated with medication, physical therapy, and psychological techniques
• Depression, anxiety, and behavioral problems can be treated with medication and psychotherapy, and
• Seizures and headaches require medication
As the patient recovers, many rehabilitation centers use the Ranchos Los Amigos Scale of Cognitive Functioning to monitor the patient’s progress in a rehabilitation program.
In most cases, patients are discharged from the rehabilitation center once they recover from PTA and can show, along with family and caregivers, that they will be safe at home. Patients are usually discharged with detailed written instructions about when it is safe to return to their regular activities.
Transitional treatment occurs between rehabilitation and the patient’s return to the community. This therapy is designed to help service members return to active duty. Fortunately, some of the best care available is provided through the Department of Defense and the Veteran’s Administration. In fact, as many as 30% of moderate to severe head injury patients are able to return to active duty, although not necessarily to their original job. When return to duty is not possible, teams of healthcare professionals work to retrain service members with skills that will help them lead a productive civilian life.
In addition to dealing with long-term physical injuries, one of the most important parts of transitional treatment involves reintegration of the patient into the family. Challenges may occur in terms of employment, finances, transportation, social life, and other areas. What was considered “normal” before the brain injury, may no longer be “normal.” Rejoining the family may involve learning to accept help and learning new roles for both the patient and family. In some cases, children may be actively involved in the care of a parent. If the patient is married, the roles of both spouses can change dramatically.
Disabilities from moderate to severe TBI can last a lifetime, and treatment may be appropriate many years after the injury. It’s important for survivors, their families, and caregivers to be involved in designing and putting into place a long-term care plan.