A traumatic brain injury (TBI), also known as an intracranial injury, is an

injury Injury is physiological damage to the living tissue of any organism, whether in humans, in other animals, or in plants. Injuries can be caused in many ways, including mechanically with penetration by sharp objects such as teeth or with ...

to the

brain The brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for ...

caused by an external force. TBI can be classified based on severity ranging from mild traumatic brain injury (mTBI/concussion) to severe traumatic brain injury. TBI can also be characterized based on mechanism ( closed or penetrating head injury) or other features (e.g., occurring in a specific location or over a widespread area).

Head injury A head injury is any injury that results in trauma to the skull or brain. The terms ''traumatic brain injury'' and ''head injury'' are often used interchangeably in the medical literature. Because head injuries cover such a broad scope of inju ...

is a broader category that may involve damage to other structures such as the

scalp The scalp is the area of the head where head hair grows. It is made up of skin, layers of connective and fibrous tissues, and the membrane of the skull. Anatomically, the scalp is part of the epicranium, a collection of structures covering th ...

and

skull The skull, or cranium, is typically a bony enclosure around the brain of a vertebrate. In some fish, and amphibians, the skull is of cartilage. The skull is at the head end of the vertebrate. In the human, the skull comprises two prominent ...

. TBI can result in physical, cognitive, social, emotional and behavioral symptoms, and outcomes can range from complete recovery to permanent

disability Disability is the experience of any condition that makes it more difficult for a person to do certain activities or have equitable access within a given society. Disabilities may be Cognitive disability, cognitive, Developmental disability, d ...

or death. Causes include falls,

vehicle collisions A traffic collision, also known as a motor vehicle collision, or car crash, occurs when a vehicle collides with another vehicle, pedestrian, animal, road debris, or other moving or stationary obstruction, such as a tree, pole or building. Tra ...

, and violence. Brain trauma occurs as a consequence of a sudden acceleration or deceleration of the brain within the skull or by a complex combination of both movement and sudden impact. In addition to the damage caused at the moment of injury, a variety of events following the injury may result in further injury. These processes may include alterations in

cerebral blood flow Cerebral circulation is the movement of blood through a network of cerebral arteries and veins supplying the brain. The rate of cerebral blood flow in an adult human is typically 750 milliliters per minute, or about 15% of cardiac output. ...

and pressure within the skull. Some of the imaging techniques used for diagnosis of moderate to severe TBI include

computed tomography A computed tomography scan (CT scan), formerly called computed axial tomography scan (CAT scan), is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers or ...

(CT) and

magnetic resonance imaging Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to generate pictures of the anatomy and the physiological processes inside the body. MRI scanners use strong magnetic fields, magnetic field gradients, and ...

(MRIs). Prevention measures include use of

seat belts A seat belt, also known as a safety belt or spelled seatbelt, is a vehicle safety device designed to secure the driver or a passenger of a vehicle against harmful movement that may result during a collision or a sudden stop. A seat belt reduce ...

helmets A helmet is a form of protective gear worn to protect the Human head, head. More specifically, a helmet complements the skull in protecting the human brain. Ceremonial or symbolic helmets (e.g., a Custodian helmet, policeman's helmet in the Unite ...

, mouth guards, following safety rules, not

drinking and driving Drunk driving (or drink-driving in British English) is the act of driving under the influence of alcohol. A small increase in the blood alcohol content increases the relative risk of a motor vehicle crash. In the United States, alcohol is in ...

fall prevention Fall prevention includes any action taken to help reduce the number of accidental falls suffered by susceptible individuals, such as the elderly and people with neurological ( Parkinson's, Multiple sclerosis, stroke survivors, Guillain-Barre ...

efforts in older adults, neuromuscular training, and safety measures for children. Depending on the injury, treatment required may be minimal or may include interventions such as medications, emergency surgery or surgery years later.

Physical therapy Physical therapy (PT), also known as physiotherapy, is a healthcare profession, as well as the care provided by physical therapists who promote, maintain, or restore health through patient education, physical intervention, disease preventio ...

speech therapy Speech is the use of the human voice as a medium for language. Spoken language combines vowel and consonant sounds to form units of meaning like words, which belong to a language's lexicon. There are many different intentional speech acts, suc ...

, recreation therapy,

occupational therapy Occupational therapy (OT), also known as ergotherapy, is a healthcare profession. Ergotherapy is derived from the Greek wiktionary:ergon, ergon which is allied to work, to act and to be active. Occupational therapy is based on the assumption t ...

and

vision therapy Vision therapy (VT), or behavioral optometry, is an umbrella term for alternative medicine treatments using eye exercises, based around the pseudoscientific claim that vision problems are the true underlying cause of learning difficulties, partic ...

may be employed for rehabilitation.

Counseling Counseling is the professional guidance of the individual by utilizing psychological methods especially in collecting case history data, using various techniques of the personal interview, and testing interests and aptitudes. This is a list of c ...

supported employment Supported employment refers to service provisions wherein people with disabilities, including intellectual disabilities, mental health, and traumatic brain injury, among others, are assisted with obtaining and maintaining employment. Supported ...

and community support services may also be useful. TBI is a major cause of death and disability worldwide, especially in children and young adults. Males sustain traumatic brain injuries around twice as often as females. The 20th century saw developments in diagnosis and treatment that decreased death rates and improved outcomes.

Classification

Traumatic brain injury is defined as damage to the brain resulting from external mechanical force, such as rapid acceleration or deceleration, impact, blast waves, or penetration by a projectile. Brain function is temporarily or permanently impaired and structural damage may or may not be detectable with current technology. TBI is one of two subsets of

acquired brain injury Acquired brain injury (ABI) is brain damage caused by events after birth, rather than as part of a genetic or congenital disorder such as fetal alcohol syndrome, perinatal illness or perinatal hypoxia. ABI can result in cognitive, physical, e ...

(brain damage that occur after birth); the other subset is non-traumatic brain injury, which does not involve external mechanical

force In physics, a force is an influence that can cause an Physical object, object to change its velocity unless counterbalanced by other forces. In mechanics, force makes ideas like 'pushing' or 'pulling' mathematically precise. Because the Magnitu ...

(examples include stroke and infection). All traumatic brain injuries are head injuries, but the latter term may also refer to injury to other parts of the head; however, the terms ''head injury'' and ''brain injury'' are often used interchangeably. Similarly, brain injuries fall under the classification of

central nervous system The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain, spinal cord and retina. The CNS is so named because the brain integrates the received information and coordinates and influences the activity o ...

injuries LaPlaca et al. (2007). p. 16 and neurotrauma. In neuropsychology research literature, in general the term "traumatic brain injury" is used to refer to non-penetrating traumatic brain injuries. TBI is usually classified based on severity, anatomical features of the injury, and the mechanism (the causative forces). Mechanism-related classification divides TBI into closed and penetrating head injury. A closed (also called nonpenetrating, or blunt) injury occurs when the brain is not exposed. A penetrating, or open, head injury occurs when an object pierces the skull and breaches the dura mater, the outermost membrane surrounding the brain.

Severity

Brain injuries can be classified into mild, moderate, and severe categories. The

Glasgow Coma Scale The Glasgow Coma Scale (GCS) is a clinical scale used to reliably measure a person's level of consciousness after a brain injury. The GCS assesses a person based on their ability to perform eye movements, speak, and move their body. These th ...

(GCS), the most commonly used system for classifying TBI severity, grades a person's

level of consciousness An altered level of consciousness is any measure of arousal other than normal. Level of consciousness (LOC) is a measurement of a person's arousability and responsiveness to stimuli from the environment. A mildly depressed level of consciousn ...

on a scale of 3–15 based on verbal, motor, and eye-opening reactions to stimuli. Marion (1999). p. 4. In general, it is agreed that a TBI with a GCS of 13 or above is mild, 9–12 is moderate, and 8 or below is severe. Similar systems exist for young children; however, the GCS grading system has limited ability to predict outcomes. Because of this, other classification systems such as the one shown in the table are also used to help determine severity. A current model developed by the

Department of Defense The United States Department of Defense (DoD, USDOD, or DOD) is an executive department of the U.S. federal government charged with coordinating and supervising the six U.S. armed services: the Army, Navy, Marines, Air Force, Space Force, ...

and Department of Veterans Affairs uses all three criteria of GCS after

resuscitation Resuscitation is the process of correcting physiological disorders (such as lack of breathing or heartbeat) in an Acute (medicine), acutely ill patient. It is an important part of intensive care medicine, anesthesiology, trauma surgery and emerg ...

, duration of

post-traumatic amnesia Post-traumatic amnesia (PTA) is a state of mental confusion, confusion that occurs immediately following a traumatic brain injury (TBI) in which the injured person is Orientation (mental), disoriented and unable to remember events that occur after ...

(PTA), and

loss of consciousness Unconsciousness is a state in which a living individual exhibits a complete, or near-complete, inability to maintain an awareness of self and environment or to respond to any human or environmental stimulus. Unconsciousness may occur as the re ...

(LOC). It also has been proposed to use changes that are visible on

neuroimaging Neuroimaging is the use of quantitative (computational) techniques to study the neuroanatomy, structure and function of the central nervous system, developed as an objective way of scientifically studying the healthy human brain in a non-invasive ...

, such as swelling, focal lesions, or diffuse injury as method of classification.

Pathological features

Systems also exist to classify TBI by its

pathological Pathology is the study of disease. The word ''pathology'' also refers to the study of disease in general, incorporating a wide range of biology research fields and medical practices. However, when used in the context of modern medical treatme ...

features. Lesions can be extra-axial, (occurring within the skull but outside of the brain) or intra-axial (occurring within the brain tissue). Damage from TBI can be focal or diffuse, confined to specific areas or distributed in a more general manner, respectively; however, it is common for both types of injury to exist in a given case. Diffuse injury manifests with little apparent damage in neuroimaging studies, but lesions can be seen with microscopy techniques

post-mortem An autopsy (also referred to as post-mortem examination, obduction, necropsy, or autopsia cadaverum) is a surgical procedure that consists of a thorough examination of a corpse by dissection to determine the cause, mode, and manner of death ...

, Granacher (2007). p. 32. and in the early 2000s, researchers discovered that diffusion tensor imaging (DTI), a way of processing MRI images that shows white matter tracts, was an effective tool for displaying the extent of

diffuse axonal injury Diffuse axonal injury (DAI) is a brain injury in which scattered lesions occur over a widespread area in white matter tracts as well as grey matter. DAI is one of the most common and devastating types of traumatic brain injury and is a major ca ...

. Types of injuries considered diffuse include edema (swelling), concussion and diffuse axonal injury, which is widespread damage to

axon An axon (from Greek ἄξων ''áxōn'', axis) or nerve fiber (or nerve fibre: see American and British English spelling differences#-re, -er, spelling differences) is a long, slender cellular extensions, projection of a nerve cell, or neuron, ...

s including

white matter White matter refers to areas of the central nervous system that are mainly made up of myelinated axons, also called Nerve tract, tracts. Long thought to be passive tissue, white matter affects learning and brain functions, modulating the distr ...

tracts and projections to the

cortex Cortex or cortical may refer to: Biology * Cortex (anatomy), the outermost layer of an organ ** Cerebral cortex, the outer layer of the vertebrate cerebrum, part of which is the ''forebrain'' *** Motor cortex, the regions of the cerebral cortex i ...

. Focal injuries often produce symptoms related to the functions of the damaged area. Research shows that the most common areas to have focal lesions in non-penetrating traumatic brain injury are the

orbitofrontal cortex The orbitofrontal cortex (OFC) is a prefrontal cortex region in the frontal lobes of the brain which is involved in the cognitive process of decision-making. In non-human primates it consists of the association cortex areas Brodmann area 11, 1 ...

(the lower surface of the frontal lobes) and the anterior

temporal lobes The temporal lobe is one of the four Lobes of the brain, major lobes of the cerebral cortex in the brain of mammals. The temporal lobe is located beneath the lateral fissure on both cerebral hemispheres of the mammalian brain. The temporal lobe ...

, areas that are involved in social behavior, emotion regulation, olfaction, and decision-making, hence the common social/emotional and judgment deficits following moderate-severe TBI. Symptoms such as

hemiparesis Hemiparesis, also called unilateral paresis, is the weakness of one entire side of the body (''wikt:hemi-#Prefix, hemi-'' means "half"). Hemiplegia, in its most severe form, is the complete paralysis of one entire side of the body. Either hemipar ...

aphasia Aphasia, also known as dysphasia, is an impairment in a person's ability to comprehend or formulate language because of dysfunction in specific brain regions. The major causes are stroke and head trauma; prevalence is hard to determine, but aph ...

can also occur when less commonly affected areas such as

motor An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy. Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power gene ...

or language areas are, respectively, damaged. One type of focal injury, cerebral laceration, occurs when the tissue is cut or torn. Such tearing is common in

in particular, because of bony protrusions on the interior skull ridge above the eyes. In a similar injury,

cerebral contusion Cerebral contusion (), a form of traumatic brain injury, is a bruise of the brain tissue. Like bruises in other tissues, cerebral contusion can be associated with multiple microhemorrhages, small blood vessel leaks into brain tissue. Contusion ...

(bruising of brain tissue), blood is mixed among tissue. In contrast,

intracranial hemorrhage Intracranial hemorrhage (ICH) refers to any form of Hemorrhage, bleeding Internal bleeding, within the Human skull, skull. It can result from trauma, vascular abnormalities, hypertension, or other medical conditions. ICH is broadly categorized ...

involves bleeding that is not mixed with tissue. Hematomas, also focal lesions, are collections of blood in or around the brain that can result from hemorrhage.

Intracerebral hemorrhage Intracerebral hemorrhage (ICH), also known as hemorrhagic stroke, is a sudden bleeding into Intraparenchymal hemorrhage, the tissues of the brain (i.e. the parenchyma), into its Intraventricular hemorrhage, ventricles, or into both. An ICH is ...

, with bleeding in the brain tissue itself, is an intra-axial lesion. Extra-axial lesions include epidural hematoma,

subdural hematoma A subdural hematoma (SDH) is a type of bleeding in which a collection of blood—usually but not always associated with a traumatic brain injury—gathers between the inner layer of the dura mater and the arachnoid mater of the meninges surrou ...

subarachnoid hemorrhage Subarachnoid hemorrhage (SAH) is bleeding into the subarachnoid space—the area between the arachnoid (brain), arachnoid membrane and the pia mater surrounding the human brain, brain. Symptoms may include a thunderclap headache, severe heada ...

, and

intraventricular hemorrhage Intraventricular hemorrhage (IVH), also known as intraventricular bleeding, is a bleeding into the brain's ventricular system, where the cerebrospinal fluid is produced and circulates through towards the subarachnoid space. It can result from p ...

. Epidural hematoma involves bleeding into the area between the skull and the dura mater, the outermost of the three membranes surrounding the brain. In subdural hematoma, bleeding occurs between the dura and the

arachnoid mater The arachnoid mater (or simply arachnoid) is one of the three meninges, the protective membranes that cover the brain and spinal cord. It is so named because of its resemblance to a spider web. The arachnoid mater is a derivative of the neural cr ...

. Subarachnoid hemorrhage involves bleeding into the space between the arachnoid membrane and the

pia mater Pia mater ( or ),Entry "pia mater"
in
Intraventricular hemorrhage occurs when there is bleeding in the ventricles.

Signs and symptoms

Symptoms are dependent on the type of TBI (diffuse or focal) and the part of the brain that is affected. Unconsciousness tends to last longer for people with injuries on the left side of the brain than for those with injuries on the right. Symptoms are also dependent on the injury's severity. With mild TBI, the patient may remain conscious or may lose consciousness for a few seconds or minutes. Other symptoms of mild TBI include headache, vomiting, nausea, lack of

motor coordination In physiology, motor coordination is the orchestrated movement of multiple body parts as required to accomplish intended actions, like walking. This coordination is achieved by adjusting kinematic and kinetic parameters associated with each bo ...

, dizziness, difficulty balancing, lightheadedness, blurred vision or tired eyes, ringing in the ears, bad taste in the mouth, fatigue or lethargy, and changes in sleep patterns. Cognitive and emotional symptoms include behavioral or mood changes, confusion, and trouble with memory, concentration, attention, or thinking. Mild TBI symptoms may also be present in moderate and severe injuries. A person with a moderate or severe TBI may have a headache that does not go away, repeated vomiting or nausea, convulsions, an inability to awaken,

dilation wiktionary:dilation, Dilation (or dilatation) may refer to: Physiology or medicine * Cervical dilation, the widening of the cervix in childbirth, miscarriage etc. * Coronary dilation, or coronary reflex * Dilation and curettage, the opening of ...

of one or both pupils, slurred speech,

(word-finding difficulties),

dysarthria Dysarthria is a speech sound disorder resulting from neurological injury of the motor component of the motor–speech system and is characterized by poor articulation of phonemes. It is a condition in which problems effectively occur with the ...

(muscle weakness that causes disordered speech), weakness or numbness in the limbs, loss of coordination, confusion, restlessness, or agitation. Common long-term symptoms of moderate to severe TBI are changes in appropriate social behavior, deficits in social judgment, and cognitive changes, especially problems with sustained attention, processing speed, and executive functioning.

Alexithymia Alexithymia, also called emotional blindness, is a neuropsychological phenomenon characterized by significant challenges in recognizing, expressing, feeling, sourcing, and describing one's emotions. It is associated with difficulties in attachme ...

, a deficiency in identifying, understanding, processing, and describing emotions occurs in 60.9% of individuals with TBI. Cognitive and social deficits have long-term consequences for the daily lives of people with moderate to severe TBI, but can be improved with appropriate rehabilitation. When the pressure within the skull (

intracranial pressure Intracranial pressure (ICP) is the pressure exerted by fluids such as cerebrospinal fluid (CSF) inside the skull and on the brain tissue. ICP is measured in millimeters of mercury ( mmHg) and at rest, is normally 7–15 mmHg for a supine adu ...

, abbreviated ICP) rises too high, it can be deadly. Signs of increased ICP include decreasing

, paralysis or weakness on one side of the body, and a blown pupil, one that fails to constrict in response to light or is slow to do so. Cushing's triad, a slow heart rate with

high blood pressure Hypertension, also known as high blood pressure, is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure usually does not cause symptoms itself. It is, however, a major ri ...

and

respiratory depression Hypoventilation (also known as respiratory depression) occurs when ventilation is inadequate (''hypo'' meaning "below") to perform needed respiratory gas exchange. By definition it causes an increased concentration of carbon dioxide (hypercapni ...

is a classic manifestation of significantly raised ICP.

Anisocoria Anisocoria is a condition characterized by an unequal size of the eyes' pupils. Affecting up to 20% of the population, anisocoria is often entirely harmless, but can be a sign of more serious medical problems. Causes Anisocoria is a common cond ...

, unequal pupil size, is another sign of serious TBI.

Abnormal posturing Abnormal posturing is an involuntary flexion or extension of the arms and legs, indicating severe brain injury. It occurs when one set of muscles becomes incapacitated while the opposing set is not, and an external stimulus such as pain caus ...

, a characteristic positioning of the limbs caused by severe diffuse injury or high ICP, is an ominous sign. Small children with moderate to severe TBI may have some of these symptoms but have difficulty communicating them. Other signs seen in young children include persistent crying, inability to be consoled, listlessness, refusal to nurse or eat, and irritability.

Causes

The most common causes of TBI in the U.S. include violence, transportation accidents, construction site mishaps, and sports. Motor bikes are major causes, increasing in significance in developing countries as other causes reduce. The estimates that between 1.6 and 3.8 million traumatic brain injuries each year are a result of sports and recreation activities in the US. In children aged two to four, falls are the most common cause of TBI, while in older children traffic accidents compete with falls for this position. Granacher (2007). p. 16. TBI is the third most common injury to result from

child abuse Child abuse (also called child endangerment or child maltreatment) is physical abuse, physical, child sexual abuse, sexual, emotional and/or psychological abuse, psychological maltreatment or Child neglect, neglect of a child, especially by a p ...

. Abuse causes 19% of cases of pediatric brain trauma, and the death rate is higher among these cases. Although men are twice as likely to have a TBI,

domestic violence Domestic violence is violence that occurs in a domestic setting, such as in a marriage Marriage, also called matrimony or wedlock, is a culturally and often legally recognised union between people called spouses. It establishes r ...

is another cause of TBI, as are work-related and industrial accidents. Firearms and blast injuries from explosions are other causes of TBI, which is the leading cause of death and disability in war zones. According to Representative Bill Pascrell (Democrat, NJ), TBI is "the signature injury of the wars in Iraq and Afghanistan."

Mechanism

Physical forces

The type, direction, intensity, and duration of forces all contribute to the characteristics and severity of TBI. Forces that may contribute to TBI include angular,

rotational Rotation or rotational/rotary motion is the circular movement of an object around a central line, known as an ''axis of rotation''. A plane figure can rotate in either a clockwise or counterclockwise sense around a perpendicular axis intersec ...

, shear, and translational forces. Even in the absence of an impact, significant acceleration or deceleration of the head can cause TBI; however in most cases, a combination of impact and acceleration is probably to blame. Forces involving the head striking or being struck by something, termed ''contact'' or ''impact loading'', are the cause of most focal injuries, and movement of the brain within the skull, termed ''noncontact'' or ''inertial loading'', usually causes diffuse injuries. The violent shaking of an infant that causes shaken baby syndrome commonly manifests as diffuse injury. In impact loading, the force sends

shock wave In physics, a shock wave (also spelled shockwave), or shock, is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a me ...

s through the skull and brain, resulting in tissue damage. Shock waves caused by penetrating injuries can also destroy tissue along the path of a projectile, compounding the damage caused by the missile itself. Damage may occur directly under the site of impact, or it may occur on the side opposite the impact ( coup and contrecoup injury, respectively). When a moving object impacts the stationary head, coup injuries are typical, while contrecoup injuries are usually produced when the moving head strikes a stationary object.

Primary and secondary injury

A large percentage of the people killed by brain trauma do not die right away but rather days to weeks after the event; rather than improving after being hospitalized, some 40% of TBI patients deteriorate. Primary brain injury (the damage that occurs at the moment of trauma when tissues and blood vessels are stretched, compressed, and torn) is not adequate to explain this deterioration; rather, it is caused by secondary injury, a complex set of cellular processes and

biochemical cascade A biochemical cascade, also known as a signaling cascade or signaling pathway, is a series of chemical reactions that occur within a biological cell when initiated by a stimulus. This stimulus, known as a first messenger, acts on a receptor that ...

s that occur in the minutes to days following the trauma. These secondary processes can dramatically worsen the damage caused by primary injury and account for the greatest number of TBI deaths occurring in hospitals. Secondary injury events include damage to the

blood–brain barrier The blood–brain barrier (BBB) is a highly selective semipermeable membrane, semipermeable border of endothelium, endothelial cells that regulates the transfer of solutes and chemicals between the circulatory system and the central nervous system ...

, release of factors that cause

inflammation Inflammation (from ) is part of the biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. The five cardinal signs are heat, pain, redness, swelling, and loss of function (Latin ''calor'', '' ...

free radical A daughter category of ''Ageing'', this category deals only with the biological aspects of ageing. Ageing Biogerontology Biological processes Causes of death Cellular processes Gerontology Life extension Metabolic disorders Metabolism ...

overload, excessive release of the

neurotransmitter A neurotransmitter is a signaling molecule secreted by a neuron to affect another cell across a Chemical synapse, synapse. The cell receiving the signal, or target cell, may be another neuron, but could also be a gland or muscle cell. Neurotra ...

glutamate Glutamic acid (symbol Glu or E; known as glutamate in its anionic form) is an α-amino acid that is used by almost all living beings in the biosynthesis of proteins. It is a Essential amino acid, non-essential nutrient for humans, meaning that ...

(

excitotoxicity In excitotoxicity, neuron, nerve cells suffer damage or death when the levels of otherwise necessary and safe neurotransmitters such as glutamic acid, glutamate become pathologically high, resulting in excessive stimulation of cell surface recept ...

), influx of calcium and sodium ions into

neuron A neuron (American English), neurone (British English), or nerve cell, is an membrane potential#Cell excitability, excitable cell (biology), cell that fires electric signals called action potentials across a neural network (biology), neural net ...

s, and dysfunction of

mitochondria A mitochondrion () is an organelle found in the cells of most eukaryotes, such as animals, plants and fungi. Mitochondria have a double membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is us ...

. Injured axons in the brain's

may separate from their cell bodies as a result of secondary injury, potentially killing those neurons. Other factors in secondary injury are changes in the blood flow to the brain;

ischemia Ischemia or ischaemia is a restriction in blood supply to any tissue, muscle group, or organ of the body, causing a shortage of oxygen that is needed for cellular metabolism (to keep tissue alive). Ischemia is generally caused by problems ...

(insufficient blood flow); cerebral hypoxia (insufficient oxygen in the brain);

cerebral edema Cerebral edema is excess accumulation of fluid ( edema) in the intracellular or extracellular spaces of the brain. This typically causes impaired nerve function, increased pressure within the skull, and can eventually lead to direct compres ...

(swelling of the brain); and raised

(the pressure within the skull). Intracranial pressure may rise due to swelling or a

mass effect ''Mass Effect'' is a military science fiction media franchise created by Casey Hudson. The franchise depicts a distant future where humanity and several alien civilizations have colonized the galaxy using technology left behind by Elder race, a ...

from a lesion, such as a hemorrhage. As a result, cerebral perfusion pressure (the pressure of blood flow in the brain) is reduced;

results. When the pressure within the skull rises too high, it can cause

brain death Brain death is the permanent, irreversible, and complete loss of Electroencephalography, brain function, which may include cessation of involuntary activity (e.g., Control of ventilation#Control of respiratory rhythm, breathing) necessary to su ...

brain herniation Brain herniation is a potentially deadly side effect of very high pressure within the skull that occurs when a part of the human brain, brain is squeezed across structures within the human skull, skull. The brain can shift across such structures ...

, in which parts of the brain are squeezed by structures in the skull.

Diagnosis

Diagnosis is suspected based on lesion circumstances and clinical evidence, most prominently a

neurological examination A neurological examination is the assessment of sensory neuron and motor responses, especially reflexes, to determine whether the nervous system is impaired. This typically includes a physical examination and a review of the patient's medical his ...

, for example checking whether the pupils constrict normally in response to light and assigning a Glasgow Coma Score. Neuroimaging helps in determining the diagnosis and prognosis and in deciding what treatments to give. DSM-5 can be utilized to diagnose TBI and its psychiatric sequelae. A mTBI, or concussion, cannot be seen on a CT or MRI. The preferred radiologic test in the emergency setting to determine the severity of a TBI is

(CT): it is quick, accurate, and widely available. Follow-up CT scans may be performed later to determine whether the injury has progressed.

Magnetic resonance imaging Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to generate pictures of the anatomy and the physiological processes inside the body. MRI scanners use strong magnetic fields, magnetic field gradients, and ...

(MRI) can show more detail than CT, and can add information about expected outcome in the long term. It is more useful than CT for detecting injury characteristics such as diffuse axonal injury in the longer term; however, MRI is not used in the emergency setting for reasons including its relative inefficacy in detecting bleeds and fractures, its lengthy acquisition of images, the inaccessibility of the patient in the machine, and its incompatibility with metal items used in emergency care. A variant of MRI since 2012 is high-definition fiber tracking (HDFT). Other techniques may be used to confirm a particular diagnosis.

X-ray An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ran ...

s are still used for head trauma, but evidence suggests they are not useful; head injuries are either so mild that they do not need imaging or severe enough to merit the more accurate CT.

Angiography Angiography or arteriography is a medical imaging technique used to visualize the inside, or lumen, of blood vessels and organs of the body, with particular interest in the arteries, veins, and the heart chambers. Modern angiography is perfo ...

may be used to detect blood vessel pathology when risk factors such as penetrating head trauma are involved.

Functional imaging Functional imaging (or physiological imaging) is a medical imaging technique of detecting or measuring changes in metabolism, blood flow, regional chemical composition, and absorption. As opposed to structural imaging, functional imaging center ...

can measure cerebral blood flow or metabolism, inferring neuronal activity in specific regions and potentially helping to predict outcome.

Neuropsychological assessment Over the past three millennia, scholars have attempted to establish connections between localized brain damage and corresponding behavioral changes. A significant advancement in this area occurred between 1942 and 1948, when Soviet neuropsycholog ...

can be performed to evaluate the long-term cognitive sequelae and to aid in the planning of the rehabilitation. Instruments range from short measures of general mental functioning to complete batteries formed of different domain-specific

tests Test(s), testing, or TEST may refer to: * Test (assessment), an educational assessment intended to measure the respondents' knowledge or other abilities Arts and entertainment * ''Test'' (2013 film), an American film * ''Test'' (2014 film) ...

Prevention

Since a major cause of TBI are vehicle accidents, their prevention or the amelioration of their consequences can both reduce the incidence and gravity of TBI. In accidents, damage can be reduced by use of seat belts, child safety seats and motorcycle helmets, and presence of roll bars and airbags. Education programs exist to lower the number of crashes. In addition, changes to public policy and safety laws can be made; these include speed limits, seat belt and helmet laws, and road engineering practices. Changes to common practices in sports have also been discussed. The appropriate use of helmets can reduce the incidence of TBI. Due to the possibility that repeatedly "heading" a ball practicing soccer could cause cumulative brain injury, the idea of introducing protective headgear for players has been proposed. Improved equipment design can enhance safety; softer baseballs reduce head injury risk. Rules against dangerous types of contact, such as "spear tackling" in

American football American football, referred to simply as football in the United States and Canada and also known as gridiron football, is a team sport played by two teams of eleven players on a rectangular American football field, field with goalposts at e ...

, when one player tackles another head first, may also reduce head injury rates. Falls can be avoided by installing grab bars in bathrooms and handrails on stairways; removing tripping hazards such as throw rugs; or installing window guards and safety gates at the top and bottom of stairs around young children. Playgrounds with shock-absorbing surfaces such as mulch or sand also prevent head injuries. Child abuse prevention is another tactic; programs exist to prevent shaken baby syndrome by educating about the dangers of shaking children. Gun safety, including keeping guns unloaded and locked, is another preventative measure. Studies on the effect of laws that aim to control access to guns in the United States have been insufficient to determine their effectiveness preventing number of deaths or injuries.

Treatment

It is important to begin emergency treatment within the so-called " golden hour" following the injury.Kluger, Jeffrey. "Dealing with Brain Injuries. ''Time Magazine,'' April 6, 2009, p. 57. Online

Accessed: May 1, 2009 People with moderate to severe injuries are likely to receive treatment in an

intensive care unit An intensive care unit (ICU), also known as an intensive therapy unit or intensive treatment unit (ITU) or critical care unit (CCU), is a special department of a hospital or health care facility that provides intensive care medicine. An inten ...

followed by a

neurosurgical Neurosurgery or neurological surgery, known in common parlance as brain surgery, is the medical specialty that focuses on the surgical treatment or rehabilitation of disorders which affect any portion of the nervous system including the brain, s ...

ward. Treatment depends on the recovery stage of the patient. In the acute stage, the primary aim is to stabilize the patient and focus on preventing further injury. This is done because the initial damage caused by trauma cannot be reversed. Rehabilitation is the main treatment for the subacute and chronic stages of recovery. International

clinical guideline A medical guideline (also called a clinical guideline, standard treatment guideline, or clinical practice guideline) is a document with the aim of guiding decisions and criteria regarding diagnosis, management, and treatment in specific areas of ...

s have been proposed with the aim of guiding decisions in TBI treatment, as defined by an authoritative examination of current

evidence Evidence for a proposition is what supports the proposition. It is usually understood as an indication that the proposition is truth, true. The exact definition and role of evidence vary across different fields. In epistemology, evidence is what J ...

Acute stage

Tranexamic acid Tranexamic acid is a medication used to treat or prevent excessive blood loss from major trauma, postpartum bleeding, surgery, tooth removal, nosebleeds, and heavy menstruation. It is also used for hereditary angioedema. It is taken eithe ...

within three hours of a head injury decreases the risk of death. Certain facilities are equipped to handle TBI better than others; initial measures include transporting patients to an appropriate treatment center. Both during transport and in hospital the primary concerns are ensuring proper oxygen supply, maintaining adequate blood flow to the brain, and controlling raised

(ICP), since high ICP deprives the brain of badly needed blood flow and can cause deadly

. Other methods to prevent damage include management of other injuries and prevention of

seizure A seizure is a sudden, brief disruption of brain activity caused by abnormal, excessive, or synchronous neuronal firing. Depending on the regions of the brain involved, seizures can lead to changes in movement, sensation, behavior, awareness, o ...

s. Some data supports the use of

hyperbaric oxygen therapy Hyperbaric medicine is medical treatment in which an increase in barometric pressure of typically air or oxygen is used. The immediate effects include reducing the size of gas emboli and raising the partial pressures of the gases present. Initial ...

to improve outcomes. Further research is required to determine the effectiveness and clinical importance of positioning the head at different angles (degrees of head-of-bed elevation) while the person is being treated in intensive care. Neuroimaging is helpful but not flawless in detecting raised ICP. A more accurate way to measure ICP is to place a

catheter In medicine, a catheter ( ) is a thin tubing (material), tube made from medical grade materials serving a broad range of functions. Catheters are medical devices that can be inserted in the body to treat diseases or perform a surgical procedure. ...

into a ventricle of the brain, which has the added benefit of allowing

cerebrospinal fluid Cerebrospinal fluid (CSF) is a clear, colorless Extracellular fluid#Transcellular fluid, transcellular body fluid found within the meninges, meningeal tissue that surrounds the vertebrate brain and spinal cord, and in the ventricular system, ven ...

to drain, releasing pressure in the skull. Treatment of raised ICP may be as simple as tilting the person's bed and straightening the head to promote blood flow through the veins of the neck.

Sedative A sedative or tranquilliser is a substance that induces sedation by reducing irritability or Psychomotor agitation, excitement. They are central nervous system (CNS) Depressant, depressants and interact with brain activity, causing its decelera ...

analgesic An analgesic drug, also called simply an analgesic, antalgic, pain reliever, or painkiller, is any member of the group of drugs used for pain management. Analgesics are conceptually distinct from anesthetics, which temporarily reduce, and in s ...

s and paralytic agents are often used. Propofol and midazolam are equally effective as sedatives. Hypertonic saline can improve ICP by reducing the amount of cerebral water (swelling), though it is used with caution to avoid electrolyte imbalances or heart failure.

Mannitol Mannitol is a type of sugar alcohol used as a sweetener and medication. It is used as a low calorie sweetener as it is poorly absorbed by the intestines. As a medication, it is used to decrease pressure in the eyes, as in glaucoma, and to l ...

, an

osmotic Osmosis (, ) is the spontaneous net movement or diffusion of solvent molecules through a selectively-permeable membrane from a region of high water potential (region of lower solute concentration) to a region of low water potential (region o ...

diuretic A diuretic () is any substance that promotes diuresis, the increased production of urine. This includes forced diuresis. A diuretic tablet is sometimes colloquially called a water tablet. There are several categories of diuretics. All diuretics ...

, appears to be as effective as hypertonic saline at reducing ICP; however, some concerns have been raised regarding some of the studies performed. Hyertonic saline is also suitable in children with severe traumatic brain injury.

Diuretic A diuretic () is any substance that promotes diuresis, the increased production of urine. This includes forced diuresis. A diuretic tablet is sometimes colloquially called a water tablet. There are several categories of diuretics. All diuretics ...

s, drugs that increase urine output to reduce excessive fluid in the system, may be used to treat high intracranial pressures, but may cause

hypovolemia Hypovolemia, also known as volume depletion or volume contraction, is a state of abnormally low extracellular fluid in the body. This may be due to either a loss of both salt and water or a decrease in blood volume. Hypovolemia refers to the loss ...

(insufficient blood volume).

Hyperventilation Hyperventilation is irregular breathing that occurs when the rate or tidal volume of breathing eliminates more carbon dioxide than the body can produce. This leads to hypocapnia, a reduced concentration of carbon dioxide dissolved in the blo ...

(larger and/or faster breaths) reduces carbon dioxide levels and causes blood vessels to constrict; this decreases blood flow to the brain and reduces ICP, but it potentially causes

and is, therefore, used only in the short term. Giving

corticosteroid Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are invo ...

s is associated with an increased risk of death, and so their routine use is not recommended. There is no strong evidence that the following pharmaceutical interventions should be recommended to routinely treat TBI:

magnesium Magnesium is a chemical element; it has Symbol (chemistry), symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 ...

, monoaminergic and

dopamine agonist A dopamine agonist is a compound that activates dopamine receptors. There are two families of dopamine receptors, D1-like and D2-like. They are all G protein-coupled receptors. D1- and D5-receptors belong to the D1-like family and the D2-like ...

progesterone Progesterone (; P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the ma ...

, aminosteroids,

excitatory amino acid reuptake inhibitor An excitatory amino acid reuptake inhibitor (EAARI) is a type of drug which inhibits the reuptake of the excitatory neurotransmitters glutamate and aspartate by blocking one or more of the excitatory amino acid transporters (EAATs). Examples of ...

s, beta-2 antagonists (bronchodilators), haemostatic and

antifibrinolytic Antifibrinolytics are a class of medication that are inhibitors of fibrinolysis. Examples include aminocaproic acid (ε-aminocaproic acid) and tranexamic acid. These lysine Lysine (symbol Lys or K) is an α-amino acid that is a precursor ...

drugs.

Endotracheal intubation Tracheal intubation, usually simply referred to as intubation, is the placement of a flexible plastic tube into the trachea (windpipe) to maintain an open airway or to serve as a conduit through which to administer certain drugs. It is frequently ...

and

mechanical ventilation Mechanical ventilation or assisted ventilation is the Medicine, medical term for using a ventilator, ventilator machine to fully or partially provide artificial ventilation. Mechanical ventilation helps move air into and out of the lungs, wit ...

may be used to ensure proper oxygen supply and provide a secure airway.

Hypotension Hypotension, also known as low blood pressure, is a cardiovascular condition characterized by abnormally reduced blood pressure. Blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps out blood and is ...

(low blood pressure), which has a devastating outcome in TBI, can be prevented by giving

intravenous fluid Intravenous therapy (abbreviated as IV therapy) is a medical technique that administers fluids, medications and nutrients directly into a person's vein. The intravenous route of administration is commonly used for rehydration or to provide nutr ...

s to maintain a normal blood pressure. Failing to maintain blood pressure can result in inadequate blood flow to the brain. Blood pressure may be kept at an artificially high level under controlled conditions by infusion of

norepinephrine Norepinephrine (NE), also called noradrenaline (NA) or noradrenalin, is an organic compound, organic chemical in the catecholamine family that functions in the brain and human body, body as a hormone, neurotransmitter and neuromodulator. The ...

or similar drugs; this helps maintain cerebral

perfusion Perfusion is the passage of fluid through the circulatory system or lymphatic system to an organ (anatomy), organ or a tissue (biology), tissue, usually referring to the delivery of blood to a capillary bed in tissue. Perfusion may also refer t ...

. Body temperature is carefully regulated because increased temperature raises the brain's

metabolic Metabolism (, from ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cellular processes; the ...

needs, potentially depriving it of nutrients. Seizures are common. While they can be treated with

benzodiazepine Benzodiazepines (BZD, BDZ, BZs), colloquially known as "benzos", are a class of central nervous system (CNS) depressant, depressant drugs whose core chemical structure is the fusion of a benzene ring and a diazepine ring. They are prescribed t ...

s, these drugs are used carefully because they can depress breathing and lower blood pressure. Anti-convulsant medications have only been found to be useful for reducing the risk of an early seizure.

Phenytoin Phenytoin (PHT), sold under the brand name Dilantin among others, is an anticonvulsant, anti-seizure medication. It is useful for the prevention of tonic-clonic seizures (also known as grand mal seizures) and focal seizures, but not absence se ...

and

Levetiracetam Levetiracetam, sold under the brand name Keppra among others, is a novel antiepileptic drug. (medication) used to treat epilepsy. It is used for Focal seizure, partial-onset, Myoclonic epilepsy, myoclonic, or tonic–clonic seizures, and is ta ...

appear to have similar levels of effectiveness for preventing early seizures. People with TBI are more susceptible to

side effects In medicine, a side effect is an effect of the use of a medicinal drug or other treatment, usually adverse but sometimes beneficial, that is unintended. Herbal and traditional medicines also have side effects. A drug or procedure usually used ...

and may react adversely to some medications. During treatment monitoring continues for signs of deterioration such as a decreasing level of consciousness. Traumatic brain injury may cause a range of serious coincidental complications that include cardiac

arrhythmias Arrhythmias, also known as cardiac arrhythmias, are irregularities in the heartbeat, including when it is too fast or too slow. Essentially, this is anything but normal sinus rhythm. A resting heart rate that is too fast – above 100 beats ...

and neurogenic

pulmonary edema Pulmonary edema (British English: oedema), also known as pulmonary congestion, is excessive fluid accumulation in the tissue or air spaces (usually alveoli) of the lungs. This leads to impaired gas exchange, most often leading to shortness ...

. These conditions must be adequately treated and stabilised as part of the core care. Surgery can be performed on mass lesions or to eliminate objects that have penetrated the brain. Mass lesions such as contusions or hematomas causing a significant mass effect ( shift of intracranial structures) are considered emergencies and are removed surgically. For intracranial hematomas, the collected blood may be removed using

suction Suction is the day-to-day term for the movement of gases or liquids along a pressure gradient with the implication that the movement occurs because the lower pressure pulls the gas or liquid. However, the forces acting in this case do not orig ...

forceps Forceps (: forceps or considered a plural noun without a singular, often a pair of forceps; the Latin plural ''forcipes'' is no longer recorded in most dictionaries) are a handheld, hinged instrument used for grasping and holding objects. Forcep ...

or it may be floated off with water. Surgeons look for hemorrhaging blood vessels and seek to control bleeding. In penetrating brain injury, damaged tissue is surgically debrided, and

craniotomy A craniotomy is a surgery, surgical operation in which a bone flap is temporarily removed from the Human skull, skull to access the Human brain, brain. Craniotomies are often critical operations, performed on patients who are suffering from brain ...

may be needed. Craniotomy, in which part of the skull is removed, may be needed to remove pieces of fractured skull or objects embedded in the brain.

Decompressive craniectomy Decompressive craniectomy ('' crani-'' + '' -ectomy'') is a neurosurgical procedure in which part of the skull is removed to allow a swelling or herniating brain room to expand without being squeezed. It is performed on victims of traumatic br ...

(DC) is performed routinely in the very short period following TBI during operations to treat hematomas; part of the skull is removed temporarily (primary DC). DC performed hours or days after TBI in order to control persistently high intracranial pressures (secondary DC), although can reduce intracranial pressure and length of stay in ICU, but have worse

(GCS) scores, and high chances of death, vegetative state, or severe disability when compared to those receiving standard medical therapies.

Chronic stage

Once medically stable, people may be transferred to a

subacute In medicine, describing a disease as acute denotation, denotes that it is of recent wikt:onset#Noun, onset; it occasionally denotes a short wikt:duration#Noun, duration. The quantification (science), quantification of how much time constitutes "sho ...

rehabilitation unit of the medical center or to an independent

rehabilitation hospital Rehabilitation hospitals, also referred to as inpatient rehabilitation hospitals, are devoted to the rehabilitation of patients with various neurological, musculoskeletal, orthopedic, and other medical conditions following stabilization of their ...

. Rehabilitation aims to improve independent functioning at home and in society, and to help adapt to disabilities. Rehabilitation has demonstrated its general effectiveness when conducted by a team of health professionals who specialize in head trauma. As for any person with neurologic deficits, a

multidisciplinary An academic discipline or academic field is a subdivision of knowledge that is taught and researched at the college or university level. Disciplines are defined (in part) and recognized by the academic journals in which research is published, ...

approach is key to optimizing outcome.

Physiatrist Physical medicine and rehabilitation (PM&R), also known as physiatry, and outside the United States as physical and rehabilitation medicine (PRM), is a branch of medicine that aims to enhance and restore functional ability and quality of life ...

s or

neurologist Neurology (from , "string, nerve" and the suffix -logia, "study of") is the branch of medicine dealing with the diagnosis and treatment of all categories of conditions and disease involving the nervous system, which comprises the brain, the ...

s are likely to be the key medical staff involved, but depending on the person, doctors of other medical specialties may also be helpful. Allied health professions such as

physiotherapy Physical therapy (PT), also known as physiotherapy, is a healthcare profession, as well as the care provided by physical therapists who promote, maintain, or restore health through patient education, physical intervention, disease preventio ...

speech and language therapy Speech is the use of the human voice as a medium for language. Spoken language combines vowel and consonant sounds to form units of meaning like words, which belong to a language's lexicon. There are many different intentional speech acts, suc ...

cognitive rehabilitation therapy Cognitive rehabilitation refers to a wide range of evidence-based interventions designed to improve cognitive functioning in brain-injured or otherwise cognitively impaired individuals to restore normal functioning, or to compensate for cognitive ...

, and

will be essential to assess function and design the rehabilitation activities for each person. Treatment of neuropsychiatric symptoms such as emotional distress and clinical depression may involve

mental health Mental health is often mistakenly equated with the absence of mental illness. However, mental health refers to a person's overall emotional, psychological, and social well-being. It influences how individuals think, feel, and behave, and how t ...

professionals such as

therapist A therapist is a person who offers any kinds of therapy. Therapists are trained professionals in the field of any types of services like psychologists, social workers, counselors, etc. They are helpful in counseling individuals for various mental ...

psychologist A psychologist is a professional who practices psychology and studies mental states, perceptual, cognitive, emotional, and social processes and behavior. Their work often involves the experimentation, observation, and explanation, interpretatio ...

s, and

psychiatrist A psychiatrist is a physician who specializes in psychiatry. Psychiatrists are physicians who evaluate patients to determine whether their symptoms are the result of a physical illness, a combination of physical and mental ailments or strictly ...

s, while

neuropsychologist Neuropsychology is a branch of psychology concerned with how a person's cognition and behavior are related to the brain and the rest of the nervous system. Professionals in this branch of psychology focus on how injuries or illnesses of the brai ...

s can help to evaluate and manage cognitive deficits. Social workers, rehabilitation support personnel, nutritionists, therapeutic recreationists, and pharmacists are also important members of the TBI rehabilitation team. After discharge from the inpatient rehabilitation treatment unit, care may be given on an

outpatient A patient is any recipient of health care services that are performed by healthcare professionals. The patient is most often ill or injured and in need of treatment by a physician, nurse, optometrist, dentist, veterinarian, or other healt ...

basis. Community-based rehabilitation will be required for a high proportion of people, including vocational rehabilitation; this supportive employment matches job demands to the worker's abilities. People with TBI who cannot live independently or with family may require care in supported living facilities such as group homes.

Respite care __NOTOC__ In the field of healthcare, respite care is either planned care or temporary emergency healthcare that is provided to the caregiver(s) of a child patient or of an adult patient. In order to support and maintain the social health of the pr ...

, including day centers and leisure facilities for disabled people, offers time off for caregivers, and activities for people with TBI. Pharmacological treatment can help to manage psychiatric or behavioral problems. Medication is also used to control post-traumatic epilepsy; however the preventive use of anti-epileptics is not recommended. In those cases where the person is bedridden due to a reduction of consciousness, has to remain in a wheelchair because of mobility problems, or has any other problem heavily impacting self-caring capacities,

caregiving A caregiver, carer or support worker is a paid or unpaid person who helps an individual with activities of daily living. Caregivers who are members of a care recipient's family or social network, who may have specific professional training, are o ...

and nursing are critical. The most effective research documented intervention approach is the activation database guided EEG biofeedback approach, which has shown significant improvements in memory abilities of the TBI subject that are far superior than traditional approaches (strategies, computers, medication intervention). Gains of 2.61 standard deviations have been documented. The TBI's auditory memory ability was superior to the control group after the treatment. There is a promising technology called activation database-guided EEG biofeedback, which has been documented to return a TBI's auditory memory ability to above the control group's performance

Effect on the gait pattern

In patients who have developed paralysis of the legs in the form of spastic hemiplegia or diplegia as a result of the traumatic brain injury, various gait patterns can be observed, the exact extent of which can only be described with the help of complex gait analysis systems. In order to facilitate interdisciplinary communication in the interdisciplinary team between those affected, doctors, physiotherapists and orthotists, a simple description of the gait pattern is useful. J. Rodda and H. K. Graham already described in 2001 how gait patterns of CP patients can be more easily recognized and defined gait types which they compared in a classification. They also described that gait patterns can vary with age. Building on this, the Amsterdam Gait Classification was developed at the free university in Amsterdam, the VU medisch centrum. A special feature of this classification is that it makes different gait patterns very recognizable and can be used in patients in whom only one leg and both legs are affected. The Amsterdam Gait Classification was developed for viewing patients with

cerebral palsy Cerebral palsy (CP) is a group of movement disorders that appear in early childhood. Signs and symptoms vary among people and over time, but include poor coordination, spasticity, stiff muscles, Paresis, weak muscles, and tremors. There may b ...

; however, it can be used just as well in patients with traumatic brain injuries. According to the Amsterdam Gait Classification, five gait types are described. To assess the gait pattern, the patient is viewed visually or via a video recording from the side of the leg to be assessed. At the point in time at which the leg to be viewed is in mid stance and the leg not to be viewed is in mid swing, the knee angle and the contact of the foot with the ground are assessed on the one hand. Classification of the gait pattern according to the Amsterdam Gait Classification: In gait type 1, the knee angle is normal and the foot contact is complete. In gait type 2, the knee angle is hyperextended and the foot contact is complete. In gait type 3, the knee angle is hyperextended and foot contact is incomplete (only on the forefoot). In gait type 4, the knee angle is bent and foot contact is incomplete (only on the forefoot). With gait type 5, which is also known as crouch gait, the knee angle is bent and the foot contact is complete.

Orthotics

To improve the gait pattern,

orthotics Orthotics () is a medical specialty that focuses on the design and application of orthoses, sometimes known as braces, calipers, or splints. An is "an externally applied device used to influence the structural and functional characteristics of ...

can be included in the therapy concept. An Orthosis can support physiotherapeutic treatment in setting the right motor impulses in order to create new cerebral connections. The orthosis must meet the requirements of the medical prescription. In addition, the orthosis must be designed by the orthotist in such a way that it achieves the effectiveness of the necessary levers, matching the gait pattern, in order to support the proprioceptive approaches of physiotherapy. The orthotic concepts of the treatment are based on the concepts for the patients with

. The characteristics of the stiffness of the orthosis shells and the adjustable dynamics in the ankle joint are important elements of the orthosis to be considered. The orthotic concepts of the treatment are based on the concepts for the patients with cerebral palsy. Due to these requirements, the development of orthoses has changed significantly in recent years, especially since around 2010. At about the same time, care concepts were developed that deal intensively with the orthotic treatment of the lower extremities in cerebral palsy. Modern materials and new functional elements enable the rigidity to be specifically adapted to the requirements that fits to the gait pattern of the patient. The adjustment of the stiffness has a decisive influence on the gait pattern and on the energy cost of walking. It is of great advantage if the stiffness of the orthosis can be adjusted separately from one another via resistances of the two functional elements in the two directions of movement,

dorsiflexion Motion, the process of movement, is described using specific anatomical terms. Motion includes movement of organs, joints, limbs, and specific sections of the body. The terminology used describes this motion according to its direction relativ ...

and plantar flexion.

Prognosis

Prognosis worsens with the severity of injury. Most TBIs are mild and do not cause permanent or long-term disability; however, all severity levels of TBI have the potential to cause significant, long-lasting disability. Permanent disability is thought to occur in 10% of mild injuries, 66% of moderate injuries, and 100% of severe injuries. Most mild TBI is completely resolved within three weeks. Almost all people with mild TBI are able to live independently and return to the jobs they had before the injury, although a small portion have mild cognitive and social impairments. Over 90% of people with moderate TBI are able to live independently, although some require assistance in areas such as physical abilities, employment, and financial managing. Most people with severe closed head injury either die or recover enough to live independently; middle ground is less common. Coma, as it is closely related to severity, is a strong predictor of poor outcome. Prognosis differs depending on the severity and location of the lesion, and access to immediate, specialised acute management. Subarachnoid hemorrhage approximately doubles mortality. Subdural hematoma is associated with worse outcome and increased mortality, while people with epidural hematoma are expected to have a good outcome if they receive surgery quickly. Diffuse axonal injury may be associated with coma when severe, and poor outcome. Following the acute stage, prognosis is strongly influenced by the patient's involvement in activity that promote recovery, which for most patients requires access to a specialised, intensive rehabilitation service. The

Functional Independence Measure The Functional Independence Measure (FIM) is an assessment tool that aims to evaluate the functional status of patients throughout the rehabilitation process following a stroke, traumatic brain injury, spinal cord injury or cancer. Its area of u ...

is a way to track progress and degree of independence throughout rehabilitation. Medical complications are associated with a bad prognosis. Examples of such complications include:

hypotension Hypotension, also known as low blood pressure, is a cardiovascular condition characterized by abnormally reduced blood pressure. Blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps out blood and is ...

(low blood pressure), hypoxia (low blood oxygen saturation), lower cerebral perfusion pressures, and longer times spent with high intracranial pressures. Patient characteristics also influence prognosis. Examples of factors thought to worsen it include: abuse of substances such as

illicit drug The prohibition of drugs through sumptuary legislation or religious law is a common means of attempting to prevent the recreational use of certain intoxicating substances. An area has a prohibition of drugs when its government uses the forc ...

s and

alcohol Alcohol may refer to: Common uses * Alcohol (chemistry), a class of compounds * Ethanol, one of several alcohols, commonly known as alcohol in everyday life ** Alcohol (drug), intoxicant found in alcoholic beverages ** Alcoholic beverage, an alco ...

and age over sixty or under two years (in children, younger age at time of injury may be associated with a slower recovery of some abilities). Other influences that may affect recovery include pre-injury intellectual ability, coping strategies, personality traits, family environment, social support systems and financial circumstances.

Life satisfaction Life satisfaction is an evaluation of a person's quality of life. It is assessed in terms of mood, relationship satisfaction, achieved goals, self-concepts, and the self-perceived ability to cope with life. Life satisfaction involves a favorabl ...

has been known to decrease for individuals with TBI immediately following the trauma, but evidence has shown that life roles, age, and depressive symptoms influence the trajectory of life satisfaction as time passes. Many people with traumatic brain injuries have poor physical fitness following their acute injury and this may result with difficulties in day-to-day activities and increased levels of fatigue.

Complications

Improvement of neurological function usually occurs for two or more years after the trauma. For many years it was believed that recovery was fastest during the first six months, but there is no evidence to support this. It may be related to services commonly being withdrawn after this period, rather than any physiological limitation to further progress. Children recover better in the immediate time frame and improve for longer periods. Complications are distinct medical problems that may arise as a result of the TBI. The results of traumatic brain injury vary widely in type and duration; they include physical, cognitive, emotional, and behavioral complications. TBI can cause prolonged or permanent effects on consciousness, such as coma,

persistent vegetative state A vegetative state (VS) or post-coma unresponsiveness (PCU) is a disorder of consciousness in which patients with severe brain damage are in a state of partial arousal rather than true awareness. After four weeks in a vegetative state, the patie ...

(in which patients are unable to achieve a state of alertness to interact with their surroundings), and

minimally conscious state A minimally conscious state (MCS) is a disorder of consciousness distinct from persistent vegetative state (PVS) and locked-in syndrome. Unlike PVS, patients with MCS have partial preservation of conscious awareness. MCS is a relatively new cate ...

(in which patients show minimal signs of being aware of self or environment). Lying still for long periods can cause complications including pressure sores,

pneumonia Pneumonia is an Inflammation, inflammatory condition of the lung primarily affecting the small air sacs known as Pulmonary alveolus, alveoli. Symptoms typically include some combination of Cough#Classification, productive or dry cough, ches ...

or other infections, progressive

multiple organ failure Multiple organ dysfunction syndrome (MODS) is altered organ function in an acutely ill patient requiring immediate medical intervention. There are different stages of organ dysfunction for certain different organs, both in acute and in chronic ...

, and

deep venous thrombosis Deep vein thrombosis (DVT) is a type of venous thrombosis involving the formation of a blood clot in a deep vein, most commonly in the legs or pelvis. A minority of DVTs occur in the arms. Symptoms can include pain, swelling, redness, and e ...

, which can cause

pulmonary embolism Pulmonary embolism (PE) is a blockage of an pulmonary artery, artery in the lungs by a substance that has moved from elsewhere in the body through the bloodstream (embolism). Symptoms of a PE may include dyspnea, shortness of breath, chest pain ...

. Infections that can follow skull fractures and penetrating injuries include

meningitis Meningitis is acute or chronic inflammation of the protective membranes covering the brain and spinal cord, collectively called the meninges. The most common symptoms are fever, intense headache, vomiting and neck stiffness and occasion ...

and

abscess An abscess is a collection of pus that has built up within the tissue of the body, usually caused by bacterial infection. Signs and symptoms of abscesses include redness, pain, warmth, and swelling. The swelling may feel fluid-filled when pre ...

es. Complications involving the blood vessels include

vasospasm Vasospasm refers to a condition in which an arterial spasm leads to vasoconstriction. This can lead to tissue ischemia (insufficient blood flow) and tissue death (necrosis). Along with physical resistance, vasospasm is a main cause of ischemi ...

, in which vessels constrict and restrict blood flow, the formation of

aneurysm An aneurysm is an outward :wikt:bulge, bulging, likened to a bubble or balloon, caused by a localized, abnormal, weak spot on a blood vessel wall. Aneurysms may be a result of a hereditary condition or an acquired disease. Aneurysms can also b ...

s, in which the side of a vessel weakens and balloons out, and stroke. Movement disorders that may develop after TBI include tremor,

ataxia Ataxia (from Greek α- negative prefix+ -τάξις rder= "lack of order") is a neurological sign consisting of lack of voluntary coordination of muscle movements that can include gait abnormality, speech changes, and abnormalities in e ...

(uncoordinated muscle movements),

spasticity Spasticity () is a feature of altered skeletal muscle performance with a combination of paralysis, increased tendon reflex activity, and hypertonia. It is also colloquially referred to as an unusual "tightness", stiffness, or "pull" of muscles. ...

(muscle contractions are overactive), myoclonus (shock-like contractions of muscles), and loss of movement range and control (in particular with a loss of movement repertoire). The risk of post-traumatic seizures increases with severity of trauma and is particularly elevated with certain types of brain trauma such as cerebral contusions or hematomas. People with early seizures, those occurring within a week of injury, have an increased risk of post-traumatic epilepsy (recurrent seizures occurring more than a week after the initial trauma). People may lose or experience altered

vision Vision, Visions, or The Vision may refer to: Perception Optical perception * Visual perception, the sense of sight * Visual system, the physical mechanism of eyesight * Computer vision, a field dealing with how computers can be made to gain und ...

hearing Hearing, or auditory perception, is the ability to perceive sounds through an organ, such as an ear, by detecting vibrations as periodic changes in the pressure of a surrounding medium. The academic field concerned with hearing is auditory sci ...

, or smell. Hormonal disturbances may occur secondary to hypopituitarism, occurring immediately or years after injury in 10 to 15% of TBI patients. Development of

diabetes insipidus Diabetes insipidus (DI) is a condition characterized by large amounts of dilute urine and increased thirst. The amount of urine produced can be nearly 20 liters per day. Reduction of fluid has little effect on the concentration of the urine. ...

or an electrolyte abnormality acutely after injury indicate need for endocrinologic work up. Signs and symptoms of hypopituitarism may develop and be screened for in adults with moderate TBI and in mild TBI with imaging abnormalities. Children with moderate to severe head injury may also develop hypopituitarism. Screening should take place 3 to 6 months, and 12 months after injury, but problems may occur more remotely. Cognitive deficits that can follow TBI include impaired attention; disrupted insight, judgement, and thought; reduced processing speed; distractibility; and deficits in executive functions such as abstract reasoning, planning, problem-solving, and multitasking.

Memory loss Amnesia is a deficit in memory caused by brain damage or brain diseases,Gazzaniga, M., Ivry, R., & Mangun, G. (2009) Cognitive Neuroscience: The biology of the mind. New York: W.W. Norton & Company. but it can also be temporarily caused by t ...

, the most common cognitive impairment among head-injured people, occurs in 20–79% of people with closed head trauma, depending on severity. People who have had TBI may also have difficulty with understanding or producing spoken or written language, or with more subtle aspects of communication such as body language.

Post-concussion syndrome Post-concussion syndrome (PCS), also known as persisting symptoms after concussion, is a set of symptoms that may continue for weeks, months, or years after a concussion. PCS is medically classified as a mild traumatic brain injury (TBI). About ...

, a set of lasting symptoms experienced after mild TBI, can include physical, cognitive, emotional and behavioral problems such as headaches, dizziness, difficulty concentrating, and depression. Multiple TBIs may have a cumulative effect. A young person who receives a second concussion before symptoms from another one have healed may be at risk for developing a very rare but deadly condition called second-impact syndrome, in which the brain swells catastrophically after even a mild blow, with debilitating or deadly results. About one in five career boxers is affected by chronic traumatic brain injury (CTBI), which causes cognitive, behavioral, and physical impairments.

Dementia pugilistica Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease linked to repeated trauma to the head. The encephalopathy symptoms can include behavioral problems, mood problems, and problems with thinking. The disease often gets worse ...

, the severe form of CTBI, affects primarily career boxers years after a boxing career. It commonly manifests as

dementia Dementia is a syndrome associated with many neurodegenerative diseases, characterized by a general decline in cognitive abilities that affects a person's ability to perform activities of daily living, everyday activities. This typically invo ...

, memory problems, and

parkinsonism Parkinsonism is a clinical syndrome characterized by tremor, bradykinesia (slowed movements), Rigidity (neurology), rigidity, and balance disorder, postural instability. Both hypokinetic features (bradykinesia and akinesia) and hyperkinetic f ...

(tremors and lack of coordination). TBI may cause emotional, social, or behavioral problems and changes in personality. These may include emotional instability, depression, anxiety,

hypomania Hypomania (literally "under mania" or "less than mania") is a Psychiatry, psychiatric Abnormality (behavior), behavioral syndrome characterized essentially by an apparently non-contextual elevation of Mood (psychology), mood (i.e., euphoria) th ...

mania Mania, also known as manic syndrome, is a Psychiatry, psychiatric Abnormality (behavior), behavioral syndrome defined as a state of Abnormality (behavior), abnormally elevated arousal, affect (psychology), affect, and energy level. During a mani ...

, apathy, irritability, problems with social judgment, and impaired conversational skills. TBI appears to predispose survivors to psychiatric disorders including

obsessive compulsive disorder Obsession may refer to: Psychology * Celebrity worship syndrome, obsessive addictive disorder to a celebrity's personal and professional life * Obsession (psychology), a persistent attachment to an object or idea * Fixation (psychology), persi ...

substance abuse Substance misuse, also known as drug misuse or, in older vernacular, substance abuse, is the use of a drug in amounts or by methods that are harmful to the individual or others. It is a form of substance-related disorder, differing definition ...

dysthymia Dysthymia ( ), known as persistent depressive disorder (PDD) in the DSM-5-TR and dysthymic disorder in ICD-11, is a psychiatric condition marked by symptoms that are similar to those of major depressive disorder, but which persist for at leas ...

, clinical depression,

bipolar disorder Bipolar disorder (BD), previously known as manic depression, is a mental disorder characterized by periods of Depression (mood), depression and periods of abnormally elevated Mood (psychology), mood that each last from days to weeks, and in ...

, and

anxiety disorder Anxiety disorders are a group of mental disorders characterized by significant and uncontrollable feelings of anxiety and fear such that a person's social, occupational, and personal functions are significantly impaired. Anxiety may cause phys ...

s. In patients who have depression after TBI, suicidal ideation is not uncommon; the suicide rate among these persons is increased 2- to 3-fold. Social and behavioral symptoms that can follow TBI include disinhibition, inability to control anger, impulsiveness, lack of initiative, inappropriate sexual activity,

asociality Asociality refers to the lack of motivation to engage in social interaction, or a preference for solitary activities. Asociality may be associated with avolition, but it can, moreover, be a manifestation of limited opportunities for social relati ...

and social withdrawal, and changes in personality. TBI also has a substantial impact on the functioning of family systems Caregiving family members and TBI survivors often significantly alter their familial roles and responsibilities following injury, creating significant change and strain on a family system. Typical challenges identified by families recovering from TBI include: frustration and impatience with one another, loss of former lives and relationships, difficulty setting reasonable goals, inability to effectively solve problems as a family, increased level of stress and household tension, changes in emotional dynamics, and overwhelming desire to return to pre-injury status. In addition, families may exhibit less effective functioning in areas including coping, problem solving and communication. Psychoeducation and counseling models have been demonstrated to be effective in minimizing family disruption.

Epidemiology

TBI is a leading cause of death and disability around the globe and presents a major worldwide social, economic, and health problem. It is the number one cause of coma,. it plays the leading role in disability due to trauma, and is the leading cause of brain damage in children and young adults. In Europe it is responsible for more years of disability than any other cause. It also plays a significant role in half of trauma deaths. Findings on the frequency of each level of severity vary based on the definitions and methods used in studies. A World Health Organization study estimated that between 70 and 90% of head injuries that receive treatment are mild, and a US study found that moderate and severe injuries each account for 10% of TBIs, with the rest mild. The incidence of TBI varies by age, gender, region and other factors. Findings of incidence and

prevalence In epidemiology, prevalence is the proportion of a particular population found to be affected by a medical condition (typically a disease or a risk factor such as smoking or seatbelt use) at a specific time. It is derived by comparing the number o ...

epidemiological Epidemiology is the study and analysis of the distribution (who, when, and where), patterns and Risk factor (epidemiology), determinants of health and disease conditions in a defined population, and application of this knowledge to prevent dise ...

studies vary based on such factors as which grades of severity are included, whether deaths are included, whether the study is restricted to hospitalized people, and the study's location. The annual incidence of mild TBI is difficult to determine but may be 100–600 people per 100,000.

Mortality

In the US, the

case fatality rate In epidemiology, case fatality rate (CFR) – or sometimes more accurately case-fatality risk – is the proportion of people who have been diagnosed with a certain disease and end up dying of it. Unlike a disease's mortality rate, the CFR does ...

is estimated to be 21% by 30 days after TBI. A study on Iraq War soldiers found that severe TBI carries a mortality of 30–50%. Deaths have declined due to improved treatments and systems for managing trauma in societies wealthy enough to provide modern emergency and neurosurgical services. The fraction of those who die after being hospitalized with TBI fell from almost half in the 1970s to about a quarter at the beginning of the 21st century. This decline in mortality has led to a concomitant increase in the number of people living with disabilities that result from TBI. Biological, clinical, and demographic factors contribute to the likelihood that an injury will be fatal. In addition, outcome depends heavily on the cause of head injury. In the US, patients with fall-related TBIs have an 89% survival rate, while only 9% of patients with firearm-related TBIs survive. In the US, firearms are the most common cause of fatal TBI, followed by vehicle accidents and then falls. Of deaths from firearms, 75% are considered to be suicides. The incidence of TBI is increasing globally, due largely to an increase in motor vehicle use in low- and middle-income countries. In developing countries, automobile use has increased faster than safety infrastructure could be introduced. In contrast, vehicle safety laws have decreased rates of TBI in high-income countries, which have seen decreases in traffic-related TBI since the 1970s. Each year in the United States, about two million people have a TBI, approximately 675,000 injuries are seen in the emergency department, and about 500,000 patients are hospitalized. The yearly incidence of TBI is estimated at 180–250 per 100,000 people in the US, 281 per 100,000 in France, 361 per 100,000 in South Africa, 322 per 100,000 in Australia, and 430 per 100,000 in England. In the European Union the yearly aggregate incidence of TBI hospitalizations and fatalities is estimated at 235 per 100,000.

Demographics

TBI is present in 85% of traumatically injured children, either alone or with other injuries. The greatest number of TBIs occur in people aged 15–24. Because TBI is more common in young people, its costs to society are high due to the loss of productive years to death and disability. The age groups most at risk for TBI are children ages five to nine and adults over age 80, and the highest rates of death and hospitalization due to TBI are in people over age 65. The incidence of fall-related TBI in First-World countries is increasing as the population ages; thus the

median The median of a set of numbers is the value separating the higher half from the lower half of a Sample (statistics), data sample, a statistical population, population, or a probability distribution. For a data set, it may be thought of as the “ ...

age of people with head injuries has increased. Regardless of age, TBI rates are higher in males. Men have twice as many TBIs as women do and have a fourfold risk of fatal head injury, and males account for two thirds of childhood and adolescent head trauma; however, when matched for severity of injury, women appear to fare more poorly than men. Moppet07

Socioeconomic status Socioeconomic status (SES) is a measurement used by economics, economists and sociology, sociologsts. The measurement combines a person's work experience and their or their family's access to economic resources and social position in relation t ...

also appears to affect TBI rates; people with lower levels of education and employment and lower socioeconomic status are at greater risk. Approximately half of those incarcerated in prisons and jails in the United States have had TBIs.

History

Head injury is present in ancient myths that may date back before recorded history. Boake and Diller (2005). p. 3 Skulls found in battleground graves with holes drilled over fracture lines suggest that

trepanation Trepanning, also known as trepanation, trephination, trephining or making a burr hole (the verb ''trepan'' derives from Old French from Medieval Latin from Ancient Greek, Greek , literally "borer, auger"), is a surgical intervention in which a ...

may have been used to treat TBI in ancient times. Granacher (2007). p. 1. Ancient

Mesopotamia Mesopotamia is a historical region of West Asia situated within the Tigris–Euphrates river system, in the northern part of the Fertile Crescent. Today, Mesopotamia is known as present-day Iraq and forms the eastern geographic boundary of ...

ns knew of head injury and some of its effects, including seizures, paralysis, and loss of sight, hearing or speech. The

Edwin Smith Papyrus The Edwin Smith Papyrus is an ancient Egyptian medical manual, medical text, named after Edwin Smith (Egyptologist), Edwin Smith who bought it in 1862, and the oldest known surgical treatise on trauma (medicine), trauma. This document, which ma ...

, written around 1650–1550 BC, describes various head injuries and symptoms and classifies them based on their presentation and tractability.

Ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...

physicians including

Hippocrates Hippocrates of Kos (; ; ), also known as Hippocrates II, was a Greek physician and philosopher of the Classical Greece, classical period who is considered one of the most outstanding figures in the history of medicine. He is traditionally referr ...

understood the brain to be the center of thought, probably due to their experience observing the effects of head trauma.

Medieval In the history of Europe, the Middle Ages or medieval period lasted approximately from the 5th to the late 15th centuries, similarly to the post-classical period of World history (field), global history. It began with the fall of the West ...

and

Renaissance The Renaissance ( , ) is a Periodization, period of history and a European cultural movement covering the 15th and 16th centuries. It marked the transition from the Middle Ages to modernity and was characterized by an effort to revive and sur ...

surgeons continued the practice of trepanation for head injury. In the Middle Ages, physicians further described head injury symptoms and the term ''concussion'' became more widespread. Concussion symptoms were first described systematically in the 16th century by Berengario da Carpi. It was first suggested in the 18th century that intracranial pressure rather than skull damage was the cause of pathology after TBI. This hypothesis was confirmed around the end of the 19th century, and opening the skull to relieve pressure was then proposed as a treatment. In the 19th century it was noted that TBI is related to the development of

psychosis In psychopathology, psychosis is a condition in which a person is unable to distinguish, in their experience of life, between what is and is not real. Examples of psychotic symptoms are delusions, hallucinations, and disorganized or inco ...

. At that time a debate arose around whether

post-concussion syndrome Post-concussion syndrome (PCS), also known as persisting symptoms after concussion, is a set of symptoms that may continue for weeks, months, or years after a concussion. PCS is medically classified as a mild traumatic brain injury (TBI). About ...

was due to a disturbance of the brain tissue or psychological factors. The debate continues today. Phineas Gage GageMillerPhoto2010-02-17 Unretouched Color Cropped

Phineas Gage GageMillerPhoto2010-02-17 Unretouched Color Cropped

Perhaps the first reported case of personality change after brain injury is that of Phineas Gage, who survived an accident in which a large iron rod was driven through his head, destroying one or both of his frontal lobes; numerous cases of personality change after brain injury have been reported since. The 20th century saw the advancement of technologies that improved treatment and diagnosis such as the development of imaging tools including CT and MRI, and, in the 21st century, diffusion tensor imaging (DTI). The introduction of intracranial pressure monitoring in the 1950s has been credited with beginning the "modern era" of head injury. Marion (1999). p. 3. Until the 20th century, the mortality rate of TBI was high and rehabilitation was uncommon; improvements in care made during World War I reduced the death rate and made rehabilitation possible. Facilities dedicated to TBI rehabilitation were probably first established during World War I. Explosives used in World War I caused many blast injuries; the large number of TBIs that resulted allowed researchers to learn about localization of brain functions. Blast-related injuries are now common problems in returning veterans from Iraq & Afghanistan; research shows that the symptoms of such TBIs are largely the same as those of TBIs involving a physical blow to the head. In the 1970s, awareness of TBI as a public health problem grew, Boake and Diller (2005). p. 8 and a great deal of progress has been made since then in brain trauma research, such as the discovery of

primary and secondary brain injury Primary and secondary brain injury are ways to classify the injury processes that occur in brain injury. In traumatic brain injury (TBI), primary brain injury occurs during the initial insult, and results from displacement of the physical structur ...

. The 1990s saw the development and dissemination of standardized guidelines for treatment of TBI, with protocols for a range of issues such as drugs and management of intracranial pressure. Research since the early 1990s has improved TBI survival; that decade was known as the "

Decade of the Brain A decade (from , , ) is a period of 10 years. Decades may describe any 10-year period, such as those of a person's life, or refer to specific groupings of calendar years. Usage Any period of ten years is a "decade". For example, the statement t ...

" for advances made in brain research.

Research directions

Diagnosis

Quantitative EEG Quantitative electroencephalography (qEEG or QEEG) is a field concerned with the numerical analysis of electroencephalography (EEG) data and associated behavioral correlates. Details Techniques used in digital signal analysis are extended to ...

and EEG, which has no specific patterns in TBI is used in research settings to differentiate between mild TBI and no TBI.

Medications

As of 2008, no medication is approved to halt the progression of the initial injury to secondary injury. The variety of pathological events presents opportunities to find treatments that interfere with the damage processes. Further research is necessary to determine if the vasoconstrictor indomethacin (indometacin) can be used to treat increased pressure in the skull following a TBI. In addition, drugs such as

NMDA receptor antagonist NMDA receptor antagonists are a class of drugs that work to receptor antagonist, antagonize, or inhibit the action of, the NMDA, ''N''-Methyl-D-aspartate receptor (NMDA receptor, NMDAR). They are commonly used as anesthetics for humans and anima ...

s to halt neurochemical cascades such as

showed promise in

animal trial In legal history, an animal trial is a trial of a non-human animal. These trials were conducted in both secular and ecclesiastic courts. Records of such trials show that they took place in Europe from the thirteenth to the eighteenth century. ...

s but failed in clinical trials. These failures could be due to factors including faults in the trial designs or in the insufficiency of a single agent to prevent the array of injury processes involved in secondary injury. Other topics of research have included investigations into

mannitol Mannitol is a type of sugar alcohol used as a sweetener and medication. It is used as a low calorie sweetener as it is poorly absorbed by the intestines. As a medication, it is used to decrease pressure in the eyes, as in glaucoma, and to l ...

dexamethasone Dexamethasone is a fluorinated glucocorticoid medication used to treat rheumatic problems, a number of skin diseases, severe allergies, asthma, chronic obstructive pulmonary disease (COPD), croup, brain swelling, eye pain following eye su ...

barbiturates Barbiturates are a class of depressant drugs that are chemically derived from barbituric acid. They are effective when used medically as anxiolytics, hypnotics, and anticonvulsants, but have physical and psychological addiction potential as ...

(no strong evidence), and

calcium channel blocker Calcium channel blockers (CCB), calcium channel antagonists or calcium antagonists are a group of medications that disrupt the movement of calcium () through calcium channels. Calcium channel blockers are used as antihypertensive drugs, i.e., as ...

s. A 2024 review reported inconsistent findings regarding the potential of

amphetamine Amphetamine (contracted from Alpha and beta carbon, alpha-methylphenethylamine, methylphenethylamine) is a central nervous system (CNS) stimulant that is used in the treatment of attention deficit hyperactivity disorder (ADHD), narcolepsy, an ...

and

methylphenidate Methylphenidate, sold under the brand names Ritalin ( ) and Concerta ( ) among others, is a central nervous system (CNS) stimulant used in the treatment of attention deficit hyperactivity disorder (ADHD) and narcolepsy. It may be taken Oral adm ...

to improve

cognitive Cognition is the "mental action or process of acquiring knowledge and understanding through thought, experience, and the senses". It encompasses all aspects of intellectual functions and processes such as: perception, attention, thought, ...

and

function following

stroke Stroke is a medical condition in which poor cerebral circulation, blood flow to a part of the brain causes cell death. There are two main types of stroke: brain ischemia, ischemic, due to lack of blood flow, and intracranial hemorrhage, hemor ...

and TBI, noting that further research was required to understand the treatment time window.

Procedures

Although

neuroprotection Neuroprotection refers to the relative preservation of neuronal structure and/or function. In the case of an ongoing insult (a neurodegenerative insult) the relative preservation of neuronal integrity implies a reduction in the rate of neuronal l ...

methods to decrease secondary injury have been the subject of interest follows TBI, trials to test agents that could halt these cellular mechanisms have met largely with failure as of 2008. For example, interest existed in cooling the injured brain; however, a 2020 Cochrane review did not find enough evidence to see if it was useful or not. Maintaining a normal temperature in the immediate period after a TBI appeared useful. One review found a lower than normal temperature was useful in adults but not children. While two other reviews found it did not appear to be useful. In addition to traditional imaging modalities, there are several devices that help to monitor brain injury and facilitate research. Microdialysis allows ongoing sampling of extracellular fluid for analysis of metabolites that might indicate ischemia or brain metabolism, such as glucose, glycerol, and glutamate. Intraparenchymal brain tissue oxygen monitoring systems (either Licox or Neurovent-PTO) are used routinely in neurointensive care in the US. A non invasive model called CerOx is in development. Research is also planned to clarify factors correlated to outcome in TBI and to determine in which cases it is best to perform CT scans and surgical procedures.

Hyperbaric oxygen therapy Hyperbaric medicine is medical treatment in which an increase in barometric pressure of typically air or oxygen is used. The immediate effects include reducing the size of gas emboli and raising the partial pressures of the gases present. Initial ...

(HBO) has been evaluated as an add on treatment following TBI. The findings of a 2012 Cochrane systematic review does not justify the routine use of hyperbaric oxygen therapy to treat people recovering from a traumatic brain injury. This review also reported that only a small number of randomized controlled trials had been conducted at the time of the review, many of which had methodological problems and poor reporting. HBO for TBI is controversial with further evidence required to determine if it has a role.

Psychological

Further research is required to determine the effectiveness of non-pharmacological treatment approaches for treating depression in children/adolescents and adults with TBI. As of 2010, the use of predictive visual tracking measurement to identify mild traumatic brain injury was being studied. In visual tracking tests, a

head-mounted display A head-mounted display (HMD) is a display device, worn on the head or as part of a helmet (see helmet-mounted display for aviation applications), that has a small display optic in front of one (monocular HMD) or each eye (binocular vision, bi ...

unit with

eye-tracking Eye tracking is the process of measuring either the point of gaze (physiology), gaze (where one is looking) or the motion of an eye relative to the head. An eye tracker is a device for measuring eye positions and Eye movement (sensory), eye mo ...

capability shows an object moving in a regular pattern. People without brain injury are able to track the moving object with smooth pursuit eye movements and correct

trajectory A trajectory or flight path is the path that an object with mass in motion follows through space as a function of time. In classical mechanics, a trajectory is defined by Hamiltonian mechanics via canonical coordinates; hence, a complete tra ...

. The test requires both attention and working memory which are difficult functions for people with mild traumatic brain injury. The question being studied, is whether results for people with brain injury will show visual-tracking

gaze In critical theory, philosophy, sociology, and psychoanalysis, the gaze (French: ''le regard''), in the figurative sense, is an individual's (or a group's) awareness and perception of other individuals, other groups, or oneself. Since the 20th ...

errors relative to the moving target.

Monitoring pressure

Pressure reactivity index is used to correlate intracranial pressure with arterial blood pressure to give information about the state of cerebral perfusion, thus guiding treatment and prevent excessively high or low blood flow to the brain. However, such method of monitoring intracranial pressure of equal or less than 20 mmHg is no better than imaging and clinical examination that monitor the neurological status of the brain in prolonging the survival, preserving the mental or functional status of the subject.

Sensory processing

In animal models of TBI, sensory processing has been widely studied to show systematic defects arise and are slowly but likely only partially recovered. It is especially characterised by an initial period of decreased activity in upper cortical layers. This period of decreased activity has also been characterised as by specific timing effects in the patterns of cortical activity in these upper layers in response to regular sensory stimuli.

References

Cited texts

* * * * ''The original version of this article contained text from th
NINDS public domain pages on TBI
''

External links

The Brain Injury Hub – information and practical advice to parents and family members of children with acquired brain injury

Defense and Veterans Brain Injury Center – U.S. Department of Defense Military Health System center for traumatic brain injury
{{Good article Medical emergencies Intensive care medicine Neurotrauma Injuries of head Disorders causing seizures