HOME

TheInfoList




Neurotrauma, brain damage or brain injury (BI) is the destruction or degeneration of
brain cells Brain cells make up the functional tissue of the brain. The rest of the brain tissue is structural or connective called the stroma which includes blood vessel The blood vessels are the components of the circulatory system that transport blood ...
. Brain injuries occur due to a wide range of internal and external factors. In general, brain damage refers to significant, undiscriminating trauma-induced damage, while
neurotoxicity Neurotoxicity is a form of toxicity Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacteria, bacterium ...
typically refers to selective, chemically induced
neuron A neuron or nerve cell is an electrically excitable cell that communicates with other cells via specialized connections called synapse In the nervous system In biology Biology is the natural science that studies life and living ...

neuron
damage. A common category with the greatest number of injuries is
traumatic brain injury A traumatic brain injury (TBI), also known as an intracranial injury, is an injury to the brain caused by an external force. TBI can be classified based on severity (ranging from mild traumatic brain injury TBI/concussionto severe traumatic ...
(TBI) following
physical trauma Injury, also known as physical trauma, is damage Damage is any change in a thing, often a physical object, that degrades it away from its initial state. It can broadly be defined as "changes introduced into a system that adversely affect its ...
or
head injury A head injury is any injury that results in trauma to the skull The skull is a bone A bone is a Stiffness, rigid tissue (anatomy), tissue that constitutes part of the skeleton in most vertebrate animals. Bones protect the various orga ...

head injury
from an outside source, and the term acquired brain injury (ABI) is used in appropriate circles to differentiate brain injuries occurring after
birth Birth is the act or process of bearing or bringing forth offspring, also referred to in technical contexts as parturition. In mammals, the process is initiated by hormones which cause the muscular walls of the uterus to contract, expelling the fe ...

birth
from injury, from a
genetic disorder A genetic disorder is a health problem caused by one or more abnormalities in the genome In the fields of molecular biology Molecular biology is the branch of biology Biology is the natural science that studies life and li ...
, or from a
congenital disorder A birth defect, also known as a congenital disorder, is a condition present at birth Birth is the act or process of bearing or bringing forth offspring, also referred to in technical contexts as parturition. In mammals, the process is initiat ...
. Primary and secondary brain injuries identify the processes involved, while
focal and diffuse brain injury Focal and diffuse brain injury are ways to classify brain injury: focal injury occurs in a specific location, while diffuse injury occurs over a more widespread area. It is common for both focal and diffuse damage to occur as a result of the same e ...
describe the severity and localization. Recent research has demonstrated that
neuroplasticity Neuroplasticity, also known as neural plasticity, or brain plasticity, is the ability of neural networks#REDIRECT Artificial neural network Artificial neural networks (ANNs), usually simply called neural networks (NNs), are computing syst ...

neuroplasticity
, which allows the brain to reorganize itself by forming new neural connections throughout life, provides for rearrangement of its workings. This allows the brain to compensate for injury and disease.


Signs and symptoms

Symptoms of brain injuries vary based on the severity of the injury or how much of the brain is affected. The three categories used for classifying the severity of brain injuries are mild, moderate or severe.


Mild brain injuries

Symptoms of a mild brain injury include headaches, confusions,
tinnitus Tinnitus is the perception of sound when no corresponding external sound is present. Nearly everyone will experience a faint "normal tinnitus" in a completely quiet room but it is only of concern if it is bothersome or interferes with normal h ...

tinnitus
, fatigue, changes in sleep patterns, mood or behavior. Other symptoms include trouble with memory, concentration, attention or thinking. Mental fatigue is a common debilitating experience and may not be linked by the patient to the original (minor) incident.
Narcolepsy Narcolepsy is a long-term Long-Term Capital Management L.P. (LTCM) was a hedge fund''A financial History of the United States Volume II: 1970–2001'', Jerry W. Markham, Chapter 5: "Bank Consolidation", M. E. Sharpe, Inc., 2002 based in Green ...
and sleep disorders are common misdiagnoses.


Moderate/severe brain injuries

Cognitive symptoms include confusion, aggressiveness, abnormal behavior, slurred speech, and coma or other disorders of consciousness. Physical symptoms include headaches that worsen or do not go away, vomiting or nausea, convulsions, abnormal dilation of the eyes, inability to awaken from sleep, weakness in extremities and loss of coordination.


Symptoms in children

Symptoms observed in children include changes in eating habits, persistent irritability or sadness, changes in attention, disrupted sleeping habits, or loss of interest in toys.


Location of brain damage predicts symptoms

Symptoms of brain injuries can also be influenced by the location of the injury and as a result impairments are specific to the part of the brain affected.
Lesion A lesion is any damage or abnormal change in the tissue of an organism, usually caused by disease or Trauma (medicine), trauma. ''Lesion'' is derived from the Latin ''laesio'' "injury". Lesions may occur in plants as well as animals. Types The ...
size is correlated with severity, recovery, and comprehension. Brain injuries often create impairment or
disability A disability is any condition that makes it more difficult for a person to do certain activities or effectively interact with the world around them (socially or materially). These conditions, or impairments, may be Cognitive disability, cogn ...

disability
that can vary greatly in severity. In cases of severe brain injuries, the likelihood of areas with permanent
disability A disability is any condition that makes it more difficult for a person to do certain activities or effectively interact with the world around them (socially or materially). These conditions, or impairments, may be Cognitive disability, cogn ...

disability
is great, including
neurocognitive deficit Neurocognitive functions are cognitive functions closely linked to the function of particular areas, neural pathways, or Cerebral cortex, cortical networks in the brain, ultimately served by the substrate of the brain's neurological matrix (i.e. at ...
s,
delusion A delusion is a false fixed belief that is not amenable to change in light of conflicting evidence. As a pathology, it is distinct from a belief based on false or incomplete information, confabulation, dogma, illusion, hallucination, or some ot ...

delusion
s (often, to be specific,
monothematic delusion A monothematic delusion is a delusional state that concerns only one particular topic. This is contrasted by what is sometimes called ''multi-thematic'' or ''polythematic'' delusions where the person has a range of delusions (typically the case of s ...
s), speech or movement problems, and
intellectual disability Intellectual disability (ID), also known as general learning disability and formerly mental retardation (MR),Rosa's Law, Pub. L. 111-256124 Stat. 2643(2010). is a generalized neurodevelopmental disorder characterized by significantly impaired in ...
. There may also be personality changes. The most severe cases result in
coma A coma is a deep state of prolonged unconsciousness Unconsciousness is a state which occurs when the ability to maintain an consciousness, awareness of self and environment is lost. It involves a complete, or near-complete, lack of responsive ...
or even
persistent vegetative state A persistent vegetative state (PVS) or post-coma unresponsiveness (PCU) is a disorder of consciousness Disorders of consciousness are medical conditions that inhibit consciousness , an English Paracelsian physician Consciousness, at its sim ...
. Even a mild incident can have long-term effects or cause symptoms to appear years later. Studies show there is a correlation between brain lesion and language, speech, and category-specific disorders. Wernicke's aphasia is associated with anomia, unknowingly making up words (
neologisms A neologism (; from Ancient Greek, Greek νέο- ''néo-'', "new" and λόγος ''lógos'', "speech, utterance") is a relatively recent or isolated term, word, or phrase that may be in the process of entering common use, but that has not yet been ...
), and problems with comprehension. The symptoms of Wernicke’s aphasia are caused by damage to the posterior section of the
superior temporal gyrus The superior temporal gyrus (STG) is one of three (sometimes two) gyri In , a gyrus (pl. ''gyri'') is a ridge on the . It is generally surrounded by one or more (depressions or furrows; sg. ''sulcus''). Gyri and sulci create the folded app ...

superior temporal gyrus
. Damage to the
Broca’s area Broca's area, or the Broca area (, also , ), is a region in the frontal lobe of the dominant Cerebral hemisphere, hemisphere, usually the left, of the Human brain, brain with functions linked to speech production. Language processing in the brain ...
typically produces symptoms like omitting functional words (
agrammatism Agrammatism is a characteristic of non-fluent aphasia. Individuals with agrammatism present with speech that is characterized by containing mainly content words, with a lack of function words. For example, when asked to describe a picture of child ...
), sound production changes,
dyslexia Dyslexia, also known as reading disorder, is a disorder characterized by difficulty reading Reading is the process of taking in the sense or meaning of letters, symbols, ''etc.'', especially by sight or touch. For educators and researche ...

dyslexia
,
dysgraphia Dysgraphia is a deficiency in the ability to write, primarily handwriting Handwriting is the writing done with a writing instrument, such as a pen or pencil, in the hand. Handwriting includes both block letters, printing and cursive styles and ...

dysgraphia
, and problems with comprehension and production. Broca’s aphasia is indicative of damage to the posterior inferior frontal gyrus of the brain. An impairment following damage to a region of the brain does not necessarily imply that the damaged area is wholly responsible for the cognitive process which is impaired, however. For example, in
pure alexia Pure may refer to: Computing * A pure function * A virtual function, pure virtual function * PureSystems, a family of computer systems introduced by IBM in 2012 * Pure Software, a company founded in 1991 by Reed Hastings to support the Purify too ...
, the ability to read is destroyed by a lesion damaging both the left visual field and the connection between the right visual field and the language areas (Broca's area and Wernicke's area). However, this does not mean one suffering from pure alexia is incapable of comprehending speech—merely that there is no connection between their working visual cortex and language areas—as is demonstrated by the fact that pure alexics can still write, speak, and even transcribe letters without understanding their meaning. Lesions to the
fusiform gyrus The fusiform gyrus, also known as the ''lateral occipitotemporal gyrus'','' ''is part of the temporal lobe The temporal lobe is one of the four major lobes of the cerebral cortex The cerebral cortex, also known as the cerebral mantle, is the o ...

fusiform gyrus
often result in
prosopagnosia Prosopagnosia (from Greek ''prósōpon'', meaning "face", and ''agnōsía'', meaning "non-knowledge"), also called face blindness, ("illILL may refer to: * '' I Love Lucy'', a landmark American television sitcom * Illorsuit Heliport (location ...

prosopagnosia
, the inability to distinguish faces and other complex objects from each other. Lesions in the
amygdala The amygdala (; plural: amygdalae or amygdalas; also '; Latin from Greek language, Greek, , ', 'almond', 'tonsil') is one of two almond-shaped clusters of nucleus (neuroanatomy), nuclei located deep and lateral and medial, medially within the ...

amygdala
would eliminate the enhanced activation seen in occipital and fusiform visual areas in response to fear with the area intact. Amygdala lesions change the functional pattern of activation to emotional stimuli in regions that are distant from the amygdala. Other lesions to the
visual cortex The visual cortex of the brain is the area of the cerebral cortex that processes visual perception, visual information. It is located in the occipital lobe. Sensory input originating from the Eye, eyes travels through the lateral geniculate nucleu ...

visual cortex
have different effects depending on the location of the damage. Lesions to , for example, can cause
blindsight Blindsight is the ability of people who are cortically blind due to lesions in their striate cortex The visual cortex of the brain A brain is an organ (anatomy), organ that serves as the center of the nervous system in all vertebrate and most i ...
in different areas of the brain depending on the size of the lesion and location relative to the
calcarine fissure The calcarine sulcus (or calcarine fissure) is an anatomical landmark located at the Caudal (anatomical term), caudal end of the Anatomical terms of location#Left and right (lateral), and medial, medial surface of the brain of humans and other prima ...
. Lesions to can cause
color-blindness Color blindness (color vision deficiency) is the decreased ability to color vision, see color or differences in color. It can impair tasks such as selecting ripe fruit, choosing clothing, and reading traffic lights. Color blindness may make so ...
, and bilateral lesions to can cause the loss of the ability to perceive motion. Lesions to the
parietal lobes The parietal lobe is one of the four major lobes of the cerebral cortex in the brain of mammals. The parietal lobe is positioned above the temporal lobe and behind the frontal lobe and central sulcus. The parietal lobe integrates sensory infor ...
may result in
agnosia Agnosia is the inability to process sensory information. Often there is a loss of ability to recognize objects, persons, sounds, shapes, or smells while the specific sense is not defective nor is there any significant memory loss. It is usually ...
, an inability to recognize complex objects, smells, or shapes, or amorphosynthesis, a loss of perception on the opposite side of the body.Denny-Brown, D., and Betty Q. Banker. "Amorphosynthesis from Left Parietal Lesion". A.M.A. Archives of Neurology and Psychiatry 71, no. 3 (March 1954): 302–13.


Non-localizing features

Brain injuries have far-reaching and varied consequences due to the nature of the brain as the main source of bodily control. Brain-injured people commonly experience issues with memory. This can be issues with either long or short-term memories depending on the location and severity of the injury. Sometimes memory can be improved through rehabilitation, although it can be permanent. Behavioral and personality changes are also commonly observed due to changes of the brain structure in areas controlling hormones or major emotions. Headaches and pain can also occur as a result of a brain injury either directly from the damage or due to neurological conditions stemming from the injury. Due to the changes in the brain as well as the issues associated with the change in physical and mental capacity, depression and low self-esteem are common side effects that can be treated with psychological help. Antidepressants must be used with caution in brain injury people due to the potential for undesired effects because of the already altered brain chemistry.


Long term psychological and physiological effects

There are multiple responses of the body to
brain injury Injury, also known as physical trauma, is damage to the body caused by external force. This may be caused by accidents, falls, hits, weapons, and other causes. Major trauma is injury that has the potential to cause prolonged disability or death ...
, occurring at different times after the initial occurrence of damage, as the functions of the
neuron A neuron or nerve cell is an electrically excitable cell that communicates with other cells via specialized connections called synapse In the nervous system In biology Biology is the natural science that studies life and living ...

neuron
s, nerve tracts, or sections of the brain can be affected by damage. The immediate response can take many forms. Initially, there may be symptoms such as swelling, pain, bruising, or loss of consciousness. Post-traumatic amnesia is also common with brain damage, as is temporary
aphasia Aphasia is an inability to comprehend or formulate language because of damage to specific brain regions. The major causes are a cerebral vascular accident (stroke) or head trauma. Aphasia can also be the result of brain tumors, brain infections ...

aphasia
, or impairment of language. As time progresses, and the severity of injury becomes clear, there are further responses that may become apparent. Due to loss of blood flow or damaged tissue, sustained during the injury,
amnesia Amnesia is a deficit in memory Memory is the faculty of the brain by which data or information is encoded, stored, and retrieved when needed. It is the retention of information over time for the purpose of influencing future action. If Fo ...

amnesia
and
aphasia Aphasia is an inability to comprehend or formulate language because of damage to specific brain regions. The major causes are a cerebral vascular accident (stroke) or head trauma. Aphasia can also be the result of brain tumors, brain infections ...

aphasia
may become permanent, and
apraxia Apraxia is a motor An engine or motor is a machine A machine is a man-made device that uses power to apply forces and control movement to perform an action. Machines can be driven by animals and people A people is a plurality of ...
has been documented in patients. Amnesia is a condition in which a person is unable to remember things.
Aphasia Aphasia is an inability to comprehend or formulate language because of damage to specific brain regions. The major causes are a cerebral vascular accident (stroke) or head trauma. Aphasia can also be the result of brain tumors, brain infections ...

Aphasia
is the loss or impairment of word comprehension or use.
Apraxia Apraxia is a motor An engine or motor is a machine A machine is a man-made device that uses power to apply forces and control movement to perform an action. Machines can be driven by animals and people A people is a plurality of ...
is a motor disorder caused by damage to the brain, and may be more common in those who have been left brain damaged, with loss of mechanical knowledge critical. Headaches, occasional dizziness, and fatigue—all temporary symptoms of brain trauma—may become permanent, or may not disappear for a long time. There are documented cases of lasting psychological effects as well, such as emotional changes often caused by damage to the various parts of the brain that control human emotions and behavior. Individuals who have experienced emotional changes related to brain damage may have emotions that come very quickly and are very intense, but have very little lasting effect. Emotional changes may not be triggered by a specific event, and can be a cause of stress to the injured party and their family and friends. Often,
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 co ...
is suggested for those who experience this effect after their injury, and may be available as an individual or group session. It is important to note that the long term psychological and physiological effects will vary by person and injury. For example, perinatal brain damage has been implicated in cases of neurodevelopmental impairments and psychiatric illnesses. If any concerning symptoms, signs, or changes to behaviors are occurring, a healthcare provider should be consulted.


Body's response to brain injury

Unlike some of the more obvious responses to brain damage, the body also has invisible physical responses which can be difficult to notice. These will generally be identified by a healthcare provider, especially as they are normal physical responses to brain damage.
Cytokines Cytokines are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling. Cytokines are peptides and cannot cross the lipid bilayer of cells to enter the cytoplasm. Cytokines have been shown to be involved in autocrine ...
are known to be induced in response to brain injury. These have diverse actions that can cause, exacerbate, mediate and/or inhibit cellular injury and repair. TGFβ seems to exert primarily neuroprotective actions, whereas TNFα might contribute to neuronal injury and exert protective effects. IL-1 mediates ischaemic, excitotoxic, and
traumatic brain injury A traumatic brain injury (TBI), also known as an intracranial injury, is an injury to the brain caused by an external force. TBI can be classified based on severity (ranging from mild traumatic brain injury TBI/concussionto severe traumatic ...
, probably through multiple actions on glia, neurons, and the vasculature. Cytokines may be useful in order to discover novel therapeutic strategies. At the current time, they are already in clinical trials.


Causes

Brain injuries can result from a number of conditions including: *
trauma Trauma most often refers to: *Major trauma, in physical medicine, severe physical injury caused by an external source *Psychological trauma, a type of damage to the psyche that occurs as a result of a severely distressing event *Traumatic injur ...
; multiple traumatic injuries can lead to
chronic traumatic encephalopathy Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease A neurodegenerative disease is caused by the progressive loss of structure or function of neuron A neuron or nerve cell is an membrane potential#Cell excitability, elec ...
. A coup-contrecoup injury occurs when the force impacting the head is not only strong enough to cause a contusion at the site of impact, but also able to move the brain and cause it to displace rapidly into the opposite side of the skull, causing an additional contusion. ** open head injury **
closed head injury Closed-head injury is a type of traumatic brain injury A traumatic brain injury (TBI), also known as an intracranial injury, is an injury to the brain caused by an external force. TBI can be classified based on severity (ranging from mild traum ...
** penetrating: when a sharp object enters the brain, causing a large damage area. Penetrating injuries caused by bullets have a 91 percent mortality rate * deceleration injuries *
poison In biology, poisons are Chemical substance, substances that can cause death, injury or harm to organs, Tissue (biology), tissues, Cell (biology), cells, and DNA usually by chemical reactions or other activity (chemistry), activity on the molecul ...

poison
ing; for example, from
heavy metals upright=1.2, Crystals of osmium, a heavy metal nearly twice as dense as lead">lead.html" ;"title="osmium, a heavy metal nearly twice as dense as lead">osmium, a heavy metal nearly twice as dense as lead Heavy metals are generally defined as ...
including mercury and compounds of lead * hypoxia, including birth hypoxia, *
tumors A neoplasm () is a type of abnormal and excessive growth of Tissue (biology), tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissu ...
*
infection An infection is the invasion of an organism's body tissues by disease-causing agents, their multiplication, and the reaction of host A host is a person responsible for guests at an event or for providing hospitality during it. Host may ...

infection
s *
stroke A stroke is a medical condition A disease is a particular abnormal condition that negatively affects the structure or function (biology), function of all or part of an organism, and that is not due to any immediate external injury. Di ...

stroke
leading to
infarct Infarction is tissue death (necrosis Necrosis (from Ancient Greek wikt:νέκρωσις, νέκρωσις ''nékrōsis'' 'death') is a form of cell injury which results in the premature death of Cell (biology), cells in living Tissue (biolo ...
, which may follow
thrombosis Thrombosis (from Ancient Greek "clotting”) is the formation of a Thrombus, blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel (a vein or an artery) is injured, the body uses pla ...

thrombosis
,
embolisms An embolism is the lodging of an embolus, a blockage-causing piece of material, inside a blood vessel. The embolus may be a blood clot (thrombus), a fat globule (fat embolism), a bubble of air or other gas (air embolism, gas embolism), amniotic f ...
, angiomas,
aneurysms An aneurysm is an outward bulging, likened to a bubble or balloon, caused by a localized, abnormal, weak spot on a blood vessel The blood vessels are the components of the circulatory system The circulatory system, also called the ca ...
, and cerebral
arteriosclerosis Arteriosclerosis is the thickening, hardening, and loss of elasticity of the walls of arteries. This process gradually restricts the blood flow to one's organs and tissues and can lead to severe health risks brought on by atherosclerosis Athero ...
. *
neurological illness A neurological disorder is any Disorder (medicine)#Disorder, disorder of the nervous system. Structural, biochemical or electrical abnormalities in the brain, spinal cord or other nerves can result in a range of symptoms. Examples of symptoms inclu ...
or disorders *
surgery Surgery ''cheirourgikē'' (composed of χείρ, "hand", and ἔργον, "work"), via la, chirurgiae, meaning "hand work". is a medical or dental specialty that uses operative manual and instrumental techniques on a person to investigate or t ...
*
Substance use disorder Substance use disorder (SUD) is the persistent use of drugs (including alcohol) despite substantial harm and adverse consequences. Substance use disorders are characterized by an array of mental/emotional, physical, and behavioral problems such as ...
*
neurotoxins Neurotoxins are toxins that are destructive to nervous tissue, nerve tissue (causing neurotoxicity). Neurotoxins are an extensive class of exogenous chemical neurological insult (medical), insultsSpencer 2000 that can adversely affect function in ...
-
pollution Pollution is the introduction of contaminant Contamination is the presence of a constituent, impurity, or some other undesirable element that spoils, corrupts, infects, makes unfit, or makes inferior a material, physical body, natural en ...

pollution
exposure or
biological Biology is the natural science Natural science is a branch of science Science (from the Latin word ''scientia'', meaning "knowledge") is a systematic enterprise that Scientific method, builds and Taxonomy (general), organizes knowl ...

biological
exposure (
Annonaceae The Annonaceae are a Family (biology), family of flowering plants consisting of trees, shrubs, or rarely lianas commonly known as the custard apple family or soursop family. With 108 accepted genera and about 2400 known species, it is the largest ...

Annonaceae
,
rotenone Rotenone is an odorless, colorless, crystalline isoflavone used as a broad-spectrum insecticide, piscicide, and pesticide. It occurs naturally in the seeds and stems of several plants, such as the jicama vine plant, and the roots of several member ...

rotenone
,
Aspergillus ''Aspergillus'' () is a genus Genus /ˈdʒiː.nəs/ (plural genera /ˈdʒen.ər.ə/) is a taxonomic rank In biological classification In biology, taxonomy () is the scientific study of naming, defining (Circumscription (taxonomy), c ...

Aspergillus
spores, West Nile Disease, Viral
meningitis Meningitis is an acute Acute may refer to: Science and technology * Acute angle ** Acute triangle ** Acute, a leaf shape in the glossary of leaf morphology#acute, glossary of leaf morphology * Acute (medicine), a disease that it is of short dur ...
).


Chemotherapy

Chemotherapy Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment Cancer Cancer is a group of diseases A disease is a particular abnormal condition that negatively affects the structure or f ...

Chemotherapy
can cause brain damage to the neural
stem cells In multicellular organisms Multicellular organisms are organism In biology, an organism (from Ancient Greek, Greek: ὀργανισμός, ''organismos'') is any individual contiguous system that embodies the Life#Biology, properties ...
and
oligodendrocyte Oligodendrocytes (), or oligodendroglia, are a type of neuroglia Glia, also called glial cells (singular ''gliocyte'') or neuroglia, are non-neuronal cell (biology), cells in the central nervous system (brain and spinal cord) and the peripher ...
cells that produce
myelin Myelin is a lipid-rich (fatty) substance that surrounds nerve cell axons (the nervous system's "wires") to Insulator (electricity), insulate them and increase the rate at which electrical impulses (called action potentials) are passed along the a ...
. Radiation and chemotherapy can lead to brain tissue damage by disrupting or stopping blood flow to the affected areas of the brain. This damage can cause long term effects such as but not limited to; memory loss, confusion, and loss of cognitive function. The brain damage caused by radiation depends on where the brain tumor is located, the amount of radiation used, and the duration of the treatment. Radiosurgery can also lead to tissue damage that results in about 1 in 20 patients requiring a second operation to remove the damaged tissue.


Wernicke-Korsakoff syndrome

Wernicke-Korsakoff syndrome can cause brain damage and results from a Vitamin B deficiency. This syndrome presents with two conditions, Wernicke’s encephalopathy and Korsakoff psychosis. Typically Wernicke’s encephalopathy precedes symptoms of Korsakoff psychosis. Wernicke’s encephalopathy causes bleeding in the thalamus or hypothalamus, which controls the nervous and endocrine system. Due to the bleeding, brain damage occurs causing problems with vision, coordination, and balance. Korsakoff psychosis typically follows after the symptoms of Wernicke’s decrease and result from chronic brain damage. Korsakoff psychosis affect memory. Wernicke-Korsakoff syndrome is typically caused by chronic heavy alcohol use or by conditions that affect nutritional absorption, including colon cancer, eating disorders and gastric bypass.


Iatrogenic

Brain lesions are sometimes intentionally inflicted during
neurosurgery Neurosurgery or neurological surgery, known in common parlance as brain surgery, is the medical specialty A medical specialty is a branch of medical practice that is focused on a defined group of patients, diseases, skills, or philosophy. Examp ...
, such as the carefully placed brain lesion used to treat
epilepsy Epilepsy is a group of non-communicable neurological disorder A neurological disorder is any disorder of the nervous system In Biology, biology, the nervous system is a Complex system, highly complex part of an animal that coordinates i ...

epilepsy
and other brain disorders. These lesions are induced by excision or by electric shocks (electrolytic lesions) to the exposed brain or commonly by infusion of excitotoxins to specific areas.


Diffuse axonal

Diffuse axonal injury Diffuse axonal injury (DAI) is a brain injury Injury, also known as physical trauma, is damage to the body caused by external force. This may be caused by accidents, falls, hits, weapons, and other causes. Major trauma is injury that has the p ...
is caused by
shearing force In solid mechanics, shearing forces are unaligned forces pushing one part of a Rigid body, body in one specific direction, and another part of the body in the opposite direction. When the forces are colinear (aligned into each other), they a ...

shearing force
s on the brain leading to lesions in the white matter tracts of the brain. These shearing forces are seen in cases where the brain had a sharp rotational acceleration, and is caused by the difference in density between white matter and grey matter.


Diagnosis

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 thre ...
(GCS) is the most widely used scoring system used to assess the level of severity of a brain injury. This method is based on the objective observations of specific traits to determine the severity of a brain injury. It is based on three traits: eye opening, verbal response, and motor response, gauged as described below. Based on the Glasgow Coma Scale severity is classified as follows, severe brain injuries score 3–8, moderate brain injuries score 9–12 and mild score 13–15. There are several imaging techniques that can aid in diagnosing and assessing the extent of brain damage, such as
computed tomography A CT scan or computed tomography scan (formerly known as computed axial tomography or CAT scan) is a medical imaging Imaging is the representation or reproduction of an object's form; especially a visual representation (i.e., the formation of ...

computed tomography
(CT) scan,
magnetic resonance imaging Magnetic resonance imaging (MRI) is a medical imaging Medical imaging is the technique and process of imaging Imaging is the representation or reproduction of an object's form; especially a visual representation (i.e., the formation of a ...
(MRI),
diffusion tensor imaging Diffusion-weighted magnetic resonance imaging (DWI or DW-MRI) is the use of specific MRI sequence An MRI sequence in magnetic resonance imaging (MRI) is a particular setting of pulse sequences and pulsed field gradients, resulting in a particular i ...
(DTI)
magnetic resonance spectroscopy Nuclear magnetic resonance spectroscopy, most commonly known as NMR spectroscopy or magnetic resonance spectroscopy (MRS), is a spectroscopic technique to observe local magnetic fields around atomic nuclei The atomic nucleus is the small, de ...
(MRS),
positron emission tomography Positron emission tomography (PET) is a functional imaging technique that uses radioactive substances known as radiotracers to visualize and measure changes in Metabolism, metabolic processes, and in other physiological activities including blo ...
(PET), and single-photon emission tomography (SPECT). CT scans and MRI are the two techniques widely used and are most effective. CT scans can show brain bleeds, fractures of the skull, fluid build up in the brain that will lead to increased cranial pressure. MRI is able to better to detect smaller injuries, detect damage within the brain, diffuse axonal injury, injuries to the brainstem, posterior fossa, and subtemporal and subfrontal regions. However, patients with pacemakers, metallic implants, or other metal within their bodies are unable to have an MRI done. Typically the other imaging techniques are not used in a clinical setting because of the cost, lack of availability.


Management


Acute

The treatment for emergency traumatic brain injuries focuses on assuring the person has enough oxygen from the brain blood supply, and on maintaining normal blood pressure to avoid further injuries of the head or neck. The person may need surgery to remove clotted blood or repair skull fractures, for which cutting a hole in the
skull The skull is a bone A bone is a rigid tissue Tissue may refer to: Biology * Tissue (biology), an ensemble of similar cells that together carry out a specific function * ''Triphosa haesitata'', a species of geometer moth found in North A ...

skull
may be necessary. Medicines used for traumatic injuries are
diuretic A diuretic () is any substance that promotes diuresis Diuresis () is increased urination Urination is the release of urine from the urinary bladder through the urethra to the outside of the body. It is the urinary system's form of excreti ...
s, anti-seizure or
coma A coma is a deep state of prolonged unconsciousness Unconsciousness is a state which occurs when the ability to maintain an consciousness, awareness of self and environment is lost. It involves a complete, or near-complete, lack of responsive ...
-inducing drugs. Diuretics reduce the fluid in tissues lowering the pressure on the brain. In the first week after a traumatic brain injury, a person may have a risk of seizures, which anti-seizure drugs help prevent. Coma-inducing drugs may be used during surgery to reduce impairments and restore blood flow. In the case of brain damage from
traumatic brain injury A traumatic brain injury (TBI), also known as an intracranial injury, is an injury to the brain caused by an external force. TBI can be classified based on severity (ranging from mild traumatic brain injury TBI/concussionto severe traumatic ...
, dexamethasone and/or
Mannitol Mannitol is a type of sugar alcohol Sugar alcohols (also called polyhydric alcohols, polyalcohols, alditols or glycitols) are organic compound In , organic compounds are generally any s that contain - . Due to carbon's ability to (form ...
may be used.


Chronic

Various professions may be involved in the medical care and
rehabilitation Rehabilitation or Rehab may refer to: Health * Rehabilitation (neuropsychology), therapy to regain or improve neurocognitive function that has been lost or diminished * Rehabilitation (wildlife), treatment of injured wildlife so they can be returne ...

rehabilitation
of someone suffering impairment after a brain injury.
Neurologist Neurology (from el, νεῦρον (neûron), "string, nerve" and the suffix -logia ''-logy'' is a suffix in the English language, used with words originally adapted from Ancient Greek ending in (''-logia''). The earliest English example ...
s,
neurosurgeon Neurosurgery or neurological surgery, known in common parlance as brain surgery, is the medical specialty A medical specialty is a branch of medical practice that is focused on a defined group of patients, diseases, skills, or philosophy. Examp ...
s, and physiatrists are
physician A physician (American English), medical practitioner (English in the Commonwealth of Nations, Commonwealth English), medical doctor, or simply doctor, is a professional who practices medicine, which is concerned with promoting, maintainin ...

physician
s specialising in treating brain injury.
Neuropsychologists Neuropsychology is a branch of psychology that is 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 often focus on how injuries or illness ...
(especially clinical neuropsychologists) are
psychologist A psychologist is a professional who practices psychology and studies normal and abnormal mental states, perceptual, cognitive, emotional, and social processes and behavior by experimenting with, and observing, interpreting, and recording how ...
s specialising in understanding the effects of brain injury and may be involved in assessing the severity or creating
rehabilitation Rehabilitation or Rehab may refer to: Health * Rehabilitation (neuropsychology), therapy to regain or improve neurocognitive function that has been lost or diminished * Rehabilitation (wildlife), treatment of injured wildlife so they can be returne ...
strategies.
Occupational therapists Occupational Therapists (OTs) are health care professionals specializing in occupational therapy Occupational therapy (OT) is a profession within healthcare Health care, health-care, or healthcare is the maintenance or improvement of health ...
may be involved in running rehabilitation programs to help restore lost function or help re-learn essential skills.
Registered nurse A registered nurse (RN) is a nurse Nursing is a profession within the health care Healthcare is the maintenance or improvement of health Health is a state of physical, mental and social well-being Well-being, also known as ''wel ...
s, such as those working in hospital
intensive care unit 220px, 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 intensiv ...
s, are able to maintain the health of the severely brain-injured with constant administration of medication and neurological monitoring, including the use of 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 thre ...
used by other health professionals to quantify extent of orientation. Physiotherapists also play a significant role in rehabilitation after a
brain injury Injury, also known as physical trauma, is damage to the body caused by external force. This may be caused by accidents, falls, hits, weapons, and other causes. Major trauma is injury that has the potential to cause prolonged disability or death ...
. In the case of a
traumatic brain injury A traumatic brain injury (TBI), also known as an intracranial injury, is an injury to the brain caused by an external force. TBI can be classified based on severity (ranging from mild traumatic brain injury TBI/concussionto severe traumatic ...
(TBIs), physiotherapy treatment during the post-acute phase may include: sensory stimulation, serial casting and splinting, fitness and aerobic training, and functional training. Sensory stimulation refers to regaining sensory perception through the use of modalities. There is no evidence to support the efficacy of this intervention. Serial casting and splinting are often used to reduce soft tissue
contractures In pathology Pathology is the study of the causesCauses, or causality, is the relationship between one event and another. It may also refer to: * Causes (band), an indie band based in the Netherlands * Causes (company), an online company ...
and muscle tone. Evidence based research reveals that serial casting can be used to increase passive range of motion (PROM) and decrease
spasticity Spasticity () is a feature of altered skeletal muscle Skeletal muscles (commonly referred to as muscles) are Organ (biology), organs of the vertebrate muscular system that are mostly attached by tendons to bones of the skeleton. The muscle ce ...
. Studies also report that fitness and aerobic training will increase
cardiovascular fitness The circulatory system, also called the cardiovascular system or the vascular system, is an Biological system, organ system that permits blood to circulate and transport nutrients (such as amino acids and electrolytes), oxygen, carbon dioxide, ...
; however the benefits will not be transferred to the functional level. Functional training may also be used to treat patients with TBIs. To date, no studies supports the efficacy of sit to stand training, arm ability training and body weight support systems (BWS). Overall, studies suggest that patients with TBIs who participate in more intense rehabilitation programs will see greater benefits in functional skills. More research is required to better understand the efficacy of the treatments mentioned above. Other treatments for brain injury include
medication A medication (also called medicament, medicine, pharmaceutical drug, medicinal drug or simply drug) is a drug used to medical diagnosis, diagnose, cure, therapy, treat, or preventive medicine, prevent disease. Drug therapy (pharmacotherapy) ...

medication
,
psychotherapy Psychotherapy (also psychological therapy or talking therapy) is the use of Psychology, psychological methods, particularly when based on regular Conversation, personal interaction, to help a person change behavior, increase happiness, and ove ...
, neuropsychological rehabilitation, snoezelen,
surgery Surgery ''cheirourgikē'' (composed of χείρ, "hand", and ἔργον, "work"), via la, chirurgiae, meaning "hand work". is a medical or dental specialty that uses operative manual and instrumental techniques on a person to investigate or t ...
, or physical implants such as deep brain stimulation.


Prognosis

Prognosis, or the likely progress of a disorder, depends on the nature, location, and cause of the brain damage (see Traumatic brain injury, Focal and diffuse brain injury, Primary and secondary brain injury). In general, neuroregeneration can occur in the peripheral nervous system but is much rarer and more difficult to assist in the central nervous system (brain or spinal cord). However, in neural development in humans, areas of the brain can learn to compensate for other damaged areas, and may increase in size and complexity and even change function, just as someone who loses a sense may gain increased acuity in another sense – a process termed
neuroplasticity Neuroplasticity, also known as neural plasticity, or brain plasticity, is the ability of neural networks#REDIRECT Artificial neural network Artificial neural networks (ANNs), usually simply called neural networks (NNs), are computing syst ...

neuroplasticity
. There are many misconceptions that revolve around brain injuries and brain damage. One misconception is that if someone has brain damage then they cannot fully recover. Recovery depends a variety of factors; such as severity and location. Testing is done to note severity and location. Not everyone fully heals from brain damage, but it is possible to have a full recovery. Brain injuries are very hard to predict in outcome. Many tests and specialists are needed to determine the likelihood of the prognosis. People with minor brain damage can have debilitating side effects; not just severe brain damage has debilitating effects. The side- effects of a brain injury depend on location and the body’s response to injury. Even a mild concussion can have long term effects that may not resolve. Another misconception is that children heal better from brain damage. Children are at greater risk for injury due to lack of maturity. It makes future development hard to predict. This is because different Cerebral cortex, cortical areas mature at different stages, with some major cell populations and their corresponding cognitive faculties remaining unrefined until early adulthood. In the case of a child with Frontal lobe, frontal brain injury, for example, the impact of the damage may be undetectable until that child fails to develop normal executive functions in his or her late teens and early twenties.


History

The foundation for understanding human behavior and brain injury can be attributed to the case of Phineas Gage and the famous case studies by Paul Broca. The first case study on Phineas Gage’s head injury is one of the most astonishing brain injuries in history. In 1848, Phineas Gage was paving way for a new railroad line when he encountered an accidental explosion of a tamping iron straight through his frontal lobe. Gage observed to be intellectually unaffected but exemplified post injury behavioral deficits. These deficits include: becoming sporadic, disrespectful, extremely profane, and gave no regard for other workers. Gage started having seizures in February, dying only four months later on May 21, 1860. Ten years later, Paul Broca examined two patients exhibiting impaired speech due to frontal lobe injuries. Broca’s first patient lacked productive speech. He saw this as an opportunity to address language localization. It wasn't until Leborgne, formally known as "tan", died when Broca confirmed the frontal lobe lesion from an autopsy. The second patient had similar speech impairments, supporting his findings on language localization. The results of both cases became a vital verification of the relationship between speech and the left cerebral hemisphere. The affected areas are known today as Broca's area, Broca’s area and Broca’s Aphasia. A few years later, a German neuroscientist, Carl Wernicke, consulted on a stroke patient. The patient experienced neither speech nor hearing impairments, but suffered from a few brain deficits. These deficits included: lacking the ability to comprehend what was spoken to him and the words written down. After his death, Wernicke examined his autopsy that found a lesion located in the left temporal region. This area became known as Wernicke's area. Wernicke later hypothesized the relationship between Wernicke's area and Broca's area, which was proven fact.


See also

* Cerebral palsy * Encephalopathy * Epilepsy * Fetal alcohol spectrum disorder * Frontal lobe injury * Head injury * Lobotomy * Nerve injury * Neurocognitive deficit * Neurology * Myogenesis * Primary and secondary brain injury * Rehabilitation (neuropsychology) * Synaptogenesis * Traumatic brain injury


References


Further reading

*


External links

* * {{DEFAULTSORT:Brain Damage Neurotrauma Neurological disorders Causes of death