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Brain injury is unpredictable in its consequences. Brain injury affects who we are, the way we think, act, and feel. It can change everything about us in a matter of seconds. The most important things to remember:
- A person with a brain injury is a person first
- No two brain injuries are exactly the same
- The effects of a brain injury are complex and vary greatly from person to person
- The effects of a brain injury depend on such factors as cause, location, and severity
A Healthy Brain
To understand what happens when the brain is injured, it is important to realize what a healthy brain is made of and what it does. The brain is enclosed inside the skull. The skull acts as a protective covering for the soft brain. The brain is made of neurons (nerve cells). The neurons form tracts that route throughout the brain. These nerve tracts carry messages to various parts of the brain. The brain uses these messages to perform functions. The functions include our coordinating our body’s systems, such as breathing, heart rate, body temperature, and metabolism; thought processing; body movements; personality; behavior; and the senses, such as vision, hearing, taste, smell, and touch. Each part of the brain serves a specific function and links with other parts of the brain to form more complex functions.
An Injured Brain
When a brain injury occurs, the functions of the neurons, nerve tracts, or sections of the brain can be affected. If the neurons and nerve tracts are affected, they can be unable or have difficulty carrying the messages that tell the brain what to do. This can change the way a person thinks, acts, feels, and moves the body. Brain injury can also change the complex internal functions of the body, such as regulating body temperature; blood pressure; bowel and bladder control. These changes can be temporary or permanent. They may cause impairment or a complete inability to perform a function.
Causes of Traumatic Brain Injury
- A traumatic brain injury occurs when an outside force impacts the head hard enough to cause the brain to move within the skull or if the force causes the skull to break and directly hurts the brain.
- A direct blow to the head can be great enough to injure the brain inside the skull. A direct force to the head can also break the skull and directly hurt the brain. This type of injury can occur from motor vehicle crashes, firearms, falls, sports, and physical violence, such as hitting or striking with an object.
- A rapid acceleration and deceleration of the head can force the brain to move back and forth across the inside of the skull. The stress from the rapid movements pulls apart nerve fibers and causes damage to brain tissue. This type of injury often occurs as a result of motor vehicle crashes and physical violence, such as Shaken Baby Syndrome.
Traumatic brain injury is an insult to the brain, not of a degenerative or congenital nature but caused by an external physical force, that may produce a diminished or altered state of consciousness, which results in an impairment of cognitive abilities or physical functioning. It can also result in the disturbance of behavioral or emotional functioning. These impairments may be either temporary or permanent and cause partial or total functional disability or psychosocial maladjustment.
Adopted by the Brain Injury Association Board of Directors, February 22, 1986. This definition is not intended as an exclusive statement of the population served by the Brain Injury Association of America.
Causes of Acquired Brain Injury
Acquired brain injury takes place at the cellular level within the brain. Therefore, injury from acquired brain injury can effect cells throughout the entire brain, instead of just in specific areas as with traumatic brain injury.
An acquired brain injury is an injury to the brain, which is not hereditary, congenital, degenerative, or induced by birth trauma. An acquired brain injury is an injury to the brain that has occurred after birth.
Causes of acquired brain injury can include, but are not limited to:
- Airway obstruction
- Near-drowning, throat swelling, choking, strangulation, crush injuries to the chest
- Electrical shock or lightening strike
- Trauma to the head and/or neck
- Traumatic brain injury with or without skull fracture, blood loss from open wounds, artery impingement from forceful impact, shock
- Vascular Disruption
- Heart attack, stroke, arteriovenous malformation (AVM), aneurysm, intracranial surgery
- Infectious disease, intracranial tumors, metabolic disorders
- Meningitis, certain venereal diseases, AIDS, insect-carried diseases, brain tumors, hypo/hyperglycemia, hepatic encephalopathy, uremic encephalopathy, seizure disorders
- Toxic exposure- poisonous chemicals and gases, such as carbon monoxide poisoning
An acquired brain injury commonly results in a change in neuronal activity, which effects the physical integrity, the metabolic activity, or the functional ability of the cell. An acquired brain injury may result in mild, moderate, or severe impairments in one or more areas, including cognition, speech-language communication; memory; attention and concentration; reasoning; abstract thinking; physical functions; psychosocial behavior; and information processing.
Adopted by the Brain Injury Association Board of Directors, March 14, 1997.
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Anyone can get a brain injury. However, statistics show that males are two times more likely than females to sustain a brain injury. The highest rates of brain injury typically occur in males ages 15-24. Individuals who have already sustained a brain injury are also at an increased risk of sustaining another brain injury. |
After an impact to the head, a person with a brain injury can experience a variety of symptoms but not necessarily all of the following symptoms. This information is not intended to be a substitute for medical advice or examination. A person with a suspected brain injury should contact a physician immediately, go to the emergency room, or call 911 in the case of an emergency. Symptoms of a traumatic brain injury include can include, but are not limited to:
- Spinal fluid (thin water-looking liquid) coming out of the ears or nose
- Loss of consciousness; however, loss of consciousness may not occur in some concussion cases
- Dilated (the black center of the eye is large and does not get smaller in light)or unequal size of pupils
- Vision changes (blurred vision or seeing double, not able to tolerate bright light, loss of eye movement, blindness)
- Dizziness, balance problems
- Respiratory failure (not breathing)
- Coma (not alert and unable to respond to others) or semicomatose state
- Paralysis, difficulty moving body parts, weakness, poor coordination
- Slow pulse
- Slow breathing rate, with an increase in blood pressure
- Vomiting
- Lethargy (sluggish, sleepy, gets tired easily)
- Headache
- Confusion
- Ringing in the ears, or changes in ability to hear
- Difficulty with thinking skills (difficulty “thinking straight”, memory problems, poor judgment, poor attention span, a slowed thought processing speed)
- Inappropriate emotional responses (irritability, easily frustrated, inappropriate crying or laughing)
- Difficulty speaking, slurred speech, difficulty swallowing
- Body numbness or tingling
- Loss of bowel control or bladder control
Symptoms of Acquired Brain Injury
Most symptoms of acquired brain injuries are very similar to that of traumatic brain injuries; however, there are some difficulties that are experienced more frequently or to a greater degree by persons with acquired brain injuries. This information is not intended to be a substitute for medical advice or examination. A person with a suspected brain injury should contact a physician immediately, go to the emergency room, or call 911 in the case of an emergency. Symptoms can include:
- Cognitive impairment- Thinking skills, especially memory
- Longer lengths of time spent in a vegetative state
- Severe behavior problems- Psychosis, depression, restlessness, combativeness, hostility
- Muscle movement disorders
For more information on brain injury call 1-800-444-6443 or send us an email by clicking here. |
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- A Diffuse Axonal Injury can be caused by shaking or strong rotation of the head, as with Shaken Baby Syndrome, or by rotational forces, such as with a car accident.
- Injury occurs because the unmoving brain lags behind the movement of the skull, causing brain structures to tear.
- There is extensive tearing of nerve tissue throughout the brain. This can cause brain chemicals to be released, causing additional injury.
- The tearing of the nerve tissue disrupts the brain’s regular communication and chemical processes.
- This disturbance in the brain can produce temporary or permanent widespread brain damage, coma, or death.
- A person with a diffuse axonal injury could present a variety of functional impairments depending on where the shearing (tears) occurred in the brain.
Source: Brain Injury Source Volume 4 Issue
- A concussion can be caused by direct blows to the head, gunshot wounds, violent shaking of the head, or force from a whiplash type injury.
- Both closed and open head injuries can produce a concussion. A concussion is the most common type of traumatic brain injury.
- A concussion is caused when the brain receives trauma from an impact or a sudden momentum or movement change. The blood vessels in the brain may stretch and cranial nerves may be damaged.
- A person may or may not experience a brief loss of consciousness (not exceeding 20 minutes). A person may remain conscious, but feel “dazed” or “punch drunk”.
- A concussion may or may not show up on a diagnostic imaging test, such as a CAT Scan.
- Skull fracture, brain bleeding, or swelling may or may not be present. Therefore, concussion is sometimes defined by exclusion and is considered a complex neurobehavioral syndrome.
- A concussion can cause diffuse axonal type injury resulting in permanent or temporary damage.
- A blood clot in the brain can occur occasionally and be fatal.
- It may take a few months to a few years for a concussion to heal.
- A contusion can be the result of a direct impact to the head.
- A contusion is a bruise (bleeding) on the brain.
- Large contusions may need to be surgically removed.
- Coup-Contrecoup Injury describes contusions that are both at the site of the impact and on the complete opposite side of the brain.
- This occurs when the force impacting the head is not only great enough to cause a contusion at the site of impact, but also is able to move the brain and cause it to slam into the opposite side of the skull, which causes the additional contusion.
- Second Impact Syndrome, also termed "recurrent traumatic brain injury," can occur when a person sustains a second traumatic brain injury before the symptoms of the first traumatic brain injury have healed. The second injury may occur from days to weeks following the first. Loss of consciousness is not required. The second impact is more likely to cause brain swelling and widespread damage.
- Because death can occur rapidly, emergency medical treatment is needed as soon as possible.
- The long-term effects of recurrent brain injury can be muscle spasms, increased muscle tone, rapidly changing emotions, hallucinations, and difficulty thinking and learning.
Penetrating injury to the brain occurs from the impact of a bullet, knife or other sharp object that forces hair, skin, bone and fragments from the object into the brain.
- Objects traveling at a low rate of speed through the skull and brain can ricochet within the skull, which widens the area of damage.
- A "through-and-through" injury occurs if an object enters the skull, goes through the brain, and exits the skull. Through-and-through traumatic brain injuries include the effects of penetration injuries, plus additional shearing, stretching and rupture of brain tissue.
(Brumback R. (1996). Oklahoma Notes: Neurology and Clinical Neuroscience. (2nd Ed.). New York: Springer.)
- The devastating traumatic brain injuries caused by bullet wounds result in a 91% firearm-related death rate overall.
(Center for Disease Control. [Online August 22, 2002: http://www.cdc.gov/ncipc/didop/tbi.htm#rate,]).
- Firearms are the single largest cause of death from traumatic brain injury.
(Center for Disease Control. [Online August 22, 2002: http://www.cdc.gov/ncipc/didop/tbi.htm#rate,]).
Shaken Baby Syndrome is a violent criminal act that causes traumatic brain injury. Shaken Baby Syndrome occurs when the perpetrator aggressively shakes a baby or young child. The forceful whiplash-like motion causes the brain to be injured.
- Blood vessels between the brain and skull rupture and bleed.
- The accumulation of blood causes the brain tissue to compress while the injury causes the brain to swell. This damages the brain cells.
- Shaken Baby Syndrome can cause seizures, lifelong disability, coma, and death.
- Irritability, changes in eating patterns, tiredness, difficulty breathing, dilated pupils, seizures, and vomiting are signs of Shaken Baby Syndrome. A baby experiencing such symptoms needs immediate emergency medical attention.
(The Shaken Baby Alliance. [Online August 22, 2002: www.shakenbaby.com])
- Locked in Syndrome is a rare neurological condition in which a person cannot physically move any part of the body except the eyes.
- The person is conscious and able to think.
Vertical eye movements and eye blinking can be used to communicate with others and operate environmental controls.
- Anoxic Brain Injury occurs when the brain does not receive any oxygen. Cells in the brain need oxygen to survive and function.
Types of Anoxic Brain Injury
- Anoxic Anoxia- Brain injury from no oxygen supplied to the brain
- Anemic Anoxia- Brain injury from blood that does not carry enough oxygen
- Toxic Anoxia- Brain injury from toxins or metabolites that block oxygen in the blood from being used
Zasler, N. Brain Injury Source, Volume 3, Issue 3, Ask the Doctor
- A Hypoxic Brain Injury results when the brain receives some, but not enough oxygen.
Types of Hypoxic Brain Injury
- Hypoxic Ischemic Brain Injury, also called Stagnant Hypoxia or Ischemic Insult- Brain injury occurs because of a lack of blood flow to the brain because of a critical reduction in blood flow or blood pressure.
Zasler, N. Brain Injury Source, Volume 3, Issue 3, Ask the Doctor
Types of Open Head Injuries
The following are terms used to describe types of skull fractures that can occur with open head injuries:
Depressed Skull Fracture - The broken piece of skull bone moves in towards the brain
Compound Skull Fracture - The scalp is cut and the skull is fractured
Basilar Skull Fracture
- The skull fracture is located at the base of the skull (neck area) and may include the opening at the base of the skull
- Can cause damage to the nerves and blood vessels that pass through the opening at the base of the skull
Battle's Sign
- The skull fracture is located at the ear's petrous bone.
- This produces large "black and blue mark" looking areas below the ear, on the jaw and neck.
- It may include damage to the nerve for hearing.
- Blood or cerebral spinal fluid may leak out of the ear. This is termed "CSF Oterrhea".
Racoon Eyes
- The skull fracture is located in the anterior cranial fossa.
- This produces "black and blue" mark looking areas around the eyes.
- Cerebral spinal fluid may leak into the sinuses. This is termed "CSF Rhinorrhea".
- Nerve damage for the sense of smell or eye functions may occur.
Diastatic Skull Fracture
- The skull of infants and children are not completely solid until they grow older.
- The skull is composed of jigsaw-like segments (cranial fissures) which are connected together by cranial sutures.
- Skull fractures that separate the cranial sutures in children prior to the closing of the cranial fissures are termed "diastatic skull fractures".
Cribiform Plate Fracture
- The cribiform plate is a thin structure located behind the nose area.
- If the cribiform plate is fractured, cerebral spinal fluid can leak from the brain area out the nose
Closed Head Injury
When a person receives an impact to the head from an outside force, but the skull does not fracture or displace this condition is termed a "closed head injury". Again, separate terminology is added to describe the brain injury. For example, a person may have a closed head injury with a severe traumatic brain injury.
- With a closed head injury, when the brain swells, the brain has no place to expand. This can cause an increase in intracranial pressure (the pressure within the skull).
- If the brain swells and has no place to expand, this can cause brain tissues to compress, causing further injury.
- As the brain swells, it may expand through any available opening in the skull, including the eye sockets. When the brain expands through the eye sockets, it can compress and impair the functions of the eye nerves. For instance, if an eye nerve, Cranial Nerve III, is compressed, a person's pupil (the dark center part of the eye) will appear dilated (big). This is one reason why medical personal may monitor a person's pupil size and intracranial pressure.
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Before we can understand what happens when a brain is injured, we must realize what a healthy brain is made of and what it does. The brain is enclosed inside the skull. The skull acts as a protective covering for the soft brain. The brain is made of neurons (nerve cells). The neurons form tracts that route throughout the brain. These nerve tracts carry messages to various parts of the brain. The brain uses these messages to perform functions. The functions include our thought processes, physical movements, personality changes, behavioral changes, and sensing and interpreting our environment. Each part of the brain serves a specific function and links with other parts of the brain to form more complex functions.
When a brain injury occurs, the functions of the neurons, nerve tracts, or sections of the brain can be effected. If the neurons and nerve tracts are effected, they can be unable or have difficulty carrying the messages that tell the brain what to do. This can result in Thinking Changes, Physical Changes, and Personality and Behavioral Changes. These changes can be temporary or permanent. They may cause impairment or a complete inability to perform a function. Some possible changes are described below.
| Memory |
Communication |
Perception |
| Decision making |
Reading and writing skills |
Thought flexibility |
| Planning |
Thought processing speed
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Safety awareness |
| Sequencing |
Problem solving skills |
New learning |
| Judgement |
Organization |
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| Attention |
Self-perception |
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| Muscle movement |
Taste |
Balance |
| Muscle coordination |
Smell |
Speech |
| Sleep |
Touch |
seizures |
| Hearing |
Fatigue |
Sexual Functioning |
| Vision |
Weakness |
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| Social skills |
Self-monitoring remarks or actions |
Frustration |
| Stress |
Emotional control and mood swings |
Reduced self-esteem |
| Denial |
Appropriateness of behavior |
Irritability or agitation |
| Motivation |
Self-centeredness |
Coping skills |
| Depression |
Anger management |
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| Anxiety |
Excessive laughing or crying |
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The brain is divided into main functional sections, called lobes. These sections or brain lobes are called the Frontal Lobe, Temporal Lobe, Parietal Lobe, Occipital Lobe, The Cerebellum, and the Brain Stem. Each has a specific function, as described below.
| Attention and concentration |
Self-monitoring |
Organization |
| Speaking (expressive language) |
Motor Planning |
Initiation |
| Awareness of abilities and limitations |
Personality |
Mental flexibility |
| Inhibition of behavior |
Emotions |
Problem Solving |
| Planning and anticipation |
Judgement |
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| Memory |
Understanding language (receptive language) |
Sequencing |
| Hearing |
Organization |
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| Sense of touch |
Spatial perception |
| Differentiation (identification) of size, shapes, and colors |
Visual perception |
| Balance |
Skilled motor activity |
| Coordination |
Visual perception |
| Breathing |
Arousal and consciousness |
Attention and concentration |
| Heart rate |
Sleep and wake cycles |
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The functional sections or lobes of the brain are also divided into right and left sides. The right side and the left side of the brain are responsible for different functions. General patterns of dysfunction can occur if an injury is on the right or left side of the brain.
| Visual-spatial impairment |
| Visual memory deficits |
| Left neglect (inattention to the left side of the body) |
| Decreased awareness of deficits |
| Altered creativity and music perception |
| Loss of “the big picture” type of thinking |
| Decreased control over left-sided body movements |
| Difficulties in understanding language (receptive language) |
| Difficulties in speaking or verbal output (expressive language) |
| Catastrophic reactions (depression, anxiety) |
| Verbal memory deficits |
| Impaired logic |
| Sequencing difficulties |
| Decreased control over right-sided body movements |
(The injuries are scattered throughout both sides of the brain)
| Reduced thinking speed |
| Confusion |
| Reduced attention and concentration |
| Fatigue |
| Impaired cognitive (thinking) skills in all areas |
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Emergency personnel typically determine the severity of neurological injury to the brain by using an assessment called the Glascow Coma Scale (GCS) to. The terms Mild Brain Injury, Moderate Brain Injury, and Severe Brain Injury are used to describe the level of initial injury in relation to the neurological severity caused to the brain. There may be no correlation between the initial Glascow Coma Scale score and the initial level of brain injury and a person’s short or long term recovery, or functional abilities. Keep in mind that there is nothing “Mild” about a brain injury—again, the term “Mild” Brain injury is used to describe a level of neurological injury. Any injury to the brain is a real and serious medical condition.
(Glascow Coma Scale score 13-15)
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Mild traumatic brain injury occurs when:
- Loss of consciousness is very brief, usually a few seconds or minutes
- Loss of consciousness does not have to occur—the person may be dazed or confused
- Testing or scans of the brain may appear normal
- A mild traumatic brain injury is diagnosed only when there is a change in the mental status at the time of injury—the person is dazed, confused, or loses consciousness. The change in mental status indicates that the person’s brain functioning has been altered, this is called a concussion.
Symptoms of mild traumatic brain injury:
- Headache
- Fatigue
- Sleep disturbance
- Irritability
- Sensitivity to noise or light
- Balance problems
- Decreased concentration and attention span
- Decreased speed of thinking
- Memory problems
- Nausea
- Depression and anxiety
- Emotional mood swings
This information is not intended to be a substitute for medical advice or examination. A person with a suspected brain injury should contact a physician immediately, go to the emergency room, or call 911 in the case of an emergency. Symptoms of Mild Traumatic Brain Injury can be temporary. The majority of people with Mild Traumatic Brain Injury recover after one year.
Department of Defense and Veteran's Head Injury Program & Brain Injury Association of America (1999). Brain Injury and You.
Horn, L.J. & Zasler, N. (1996). Medical Rehabilitation of Traumatic Brain Injury. Hanley & Belfus, Inc: Philadelphia, PA.
Kay, T. Brain Injury Association of America. Mild traumatic brain injury.
(Glascow Coma Scale core 9-12)
A moderate traumatic brain injury occurs when:
- A loss of consciousness lasts from a few minutes to a few hours
- Confusion lasts from days to weeks
- Physical, cognitive, and/or behavioral impairments last for months or are permanent.
Persons with moderate traumatic brain injury generally can make a good recovery with treatment or successfully learn to compensate for their deficits.
Department of Defense and Veteran's Head Injury Program & Brain Injury Association of America (1999). Brain Injury and You.
(Glascow Coma Score 8 or less)
Severe brain injury occurs when a prolonged unconscious state or coma lasts days, weeks, or months. Severe brain injury is further categorized into subgroups with separate features:
- Coma
- Vegetative State
- Persistent Vegetative State
- Minimally Responsive State
- Akinetic Mutism
- Locked-in Syndrome
Coma
Coma is defined as a state of unconsciousness from which the individual cannot be awakened, in which the individual responds minimally or not at all to stimuli, and initiates no voluntary activities.
- Persons in a coma appear to be asleep, but cannot be awakened
- There is no meaningful response to stimulation.
Persons who sustain a severe brain injury can make significant improvements, but are often left with permanent physical, cognitive, or behavioral impairments.
Department of Defense and Veteran’s Head Injury Program & Brain Injury Association of America (1999). Brain Injury and You.
Vegetative State (VS)
Vegetative State (VS) describes a severe brain injury in which:
- Arousal is present, but the ability to interact with the environment is not.
- Eye opening can be spontaneous or in response to stimulation
- General responses to pain exist, such as increased heart rate, increased respiration, posturing, or sweating
- Sleep-wakes cycles, respiratory functions, and digestive functions return
There is no test to specifically diagnose Vegetative State; the diagnosis is made only by repetitive neurobehavioral assessments.
Giacino, J. & Zasler, N. (1995). Outcome after severe traumatic brain injury: Coma, the vegetative state, and the minimally responsive state. Journal of Head Trauma Rehabilitation, 10, 40-56.
Persistent Vegetative State (PVS)
Persistent Vegetative State (PVS) is a term used for a Vegetative State that has lasted for more than a month.
- The criteria is the same as for Vegetative State
The use of this term is considered controversial because it implies a prognosis.
Giacino, J. & Zasler, N. (1995). Outcome after severe traumatic brain injury: Coma, the vegetative state, and the minimally responsive state. Journal of Head Trauma Rehabilitation, 10, 40-56.
Minimally Responsive State (MR)
Minimally Responsive State (MR) is the term used for a severe traumatic brain injury in which a person is no longer in a coma or a Vegetative State. Persons in a Minimally Responsive State demonstrate:
- Primitive reflexes
- Inconsistent ability to follow simple commands
- An awareness of environmental stimulation
The frequency and the conditions in which a response was made are considered when assessing the meaningfulness or purposefulness of a behavior.
Giacino, J. & Zasler, N. (1995). Outcome after severe traumatic brain injury: Coma, the vegetative state, and the minimally responsive state. Journal of Head Trauma Rehabilitation, 10, 40-56.
Akinetic Mutism
Akinetic Mutism is a neurobehavioral condition that results when the dopaminergic pathways in the brain are damaged. Damage to these pathways results in:
- Minimal amount of body movement
- Little or no spontaneous speech
- Speech which can be elicited (For example, the person can answer a question if asked, but otherwise does not voluntarily start saying anything).
- Eye opening and visual tracking
- Infrequent and incomplete ability to follow commands
- Vigilance and agitation for Frontal Akinetic Mutism
Akinetic Mutism is different from the Minimally Responsive State because the lack of movement and speech with Akinetic Mutism is not because of neuromuscular disturbance.
Giacino, J. & Zasler, N. (1995). Outcome after severe traumatic brain injury: Coma, the vegetative state, and the minimally responsive state. Journal of Head Trauma Rehabilitation, 10, 40-56.
Locked in Syndrome
Locked in Syndrome is a rare neurological condition in which a person cannot physically move any part of the body except the eyes. The person is conscious and able to think.
- Vertical eye movements and eye blinking can be used to communicate with others and operate environmental controls.
Brain Death
Brain death can result from a very severe injury to the brain. When brain death occurs, the brain shows no sign of functioning. The physician performs a specific formal brain death examination.
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