Brain damage
Encyclopedia
"Brain damage" or "brain injury" (BI) is the destruction or degeneration of brain cells. Brain injuries occur due to a wide range of internal and external factors. A common category with the greatest number of injuries is traumatic brain injury
(TBI) following physical trauma
or 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
, from injury due to a disorder
or congenital
malady
.
which can vary greatly in severity. In cases of serious brain injuries, the likelihood of areas with permanent disability
is great, including neurocognitive deficits, delusion
s (often specifically monothematic delusion
s), speech or movement problems, and mental handicap
. There will also be personality changes. The most severe cases result in coma
or even persistent vegetative state
. Even a mild incident can have long term effects or cause symptoms to appear years later.
Mental fatigue is a common debilitating experience and may not be linked by the patient to the original (minor) incident. Narcolepsy and sleep disorders are common misdiagnoses.
Brain injury whether from stroke, alcohol abuse, traumatic brain injury, or vitamin B deficiency can sometimes result in Korsakoff's Psychosis, where the individual engages in confabulations. Confabulations involve the inability to separate daydream memory from real memory and the filling in of memory lapses with daydreams. Like all other symptoms of brain injuries, Korsakoff's Psychosis is often mis-diagnosed, in this case as schizophrenia.
es, injuries
, and as a result of iatrogenesis
(adverse effects of medical treatment). Possible causes of widespread (diffuse) brain damage include prolonged hypoxia
(shortage of oxygen
), poison
ing by teratogens (including alcohol
), infection
, and neurological illness. Chemotherapy
can cause brain damage to the neural stem cells and oligodendrocyte
cells that produce myelin
. Common causes of focal or localized brain damage
are physical trauma
(traumatic brain injury
, stroke
, aneurysm
, surgery
, other neurological disorder
), and heavy metals
causing poisoning
including by mercury and its compounds of lead or blows to the back of skull.
of someone who suffers impairment after a brain injury. Neurologist
s, neurosurgeons, and physiatrist
s are physician
s who specialise in treating brain injury. neuropsychologists
(especially clinical neuropsychologists
) are psychologist
s who specialise in understanding the effects of brain injury and may be involved in assessing the severity or creating rehabilitation
strategies. Occupational therapists
may be involved in running rehabilitation programs to help restore lost function or help re-learn essential skills. Registered nurse
s, such as those working in hospital intensive care unit
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
used by other health professionals to quantify extent of orientation.
The effects of impairment or disability
resulting from brain injury may be treated by a number of methods, including medication
, psychotherapy
, neuropsychological rehabilitation
, snoezelen
, surgery
, or physical implants such as deep brain stimulation
.
In the case of brain damage from traumatic brain injury
, dexamethasone and/or Mannitol
may be used.
).
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
.
It is a common misconception that a brain injury sustained during childhood always has a better chance of successful recovery than similar injury acquired in adult life. It is contested that in recent studies, severe brain injuries inflicted upon children can be alleviated by the interaction of nicotinamide repropagation in nerve cells. However, the consequences of childhood injury may simply be more difficult to detect in the short term. This is because different 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 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.
Traumatic brain injury
Traumatic brain injury , also known as intracranial injury, occurs when an external force traumatically injures the brain. TBI can be classified based on severity, mechanism , or other features...
(TBI) following physical trauma
Physical trauma
Trauma refers to "a body wound or shock produced by sudden physical injury, as from violence or accident." It can also be described as "a physical wound or injury, such as a fracture or blow." Major trauma can result in secondary complications such as circulatory shock, respiratory failure and death...
or head injury
Head injury
Head injury refers to trauma of the head. This may or may not include injury to the brain. However, the terms traumatic brain injury and head injury are often used interchangeably in medical literature....
from an outside source, and the term acquired brain injury
Acquired brain injury
An acquired brain injury 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, emotional, or behavioural impairments that lead to permanent...
(ABI) is used in appropriate circles, to differentiate brain injuries occurring after birth
Birth
Birth is the act or process of bearing or bringing forth offspring. The offspring is brought forth from the mother. The time of human birth is defined as the time at which the fetus comes out of the mother's womb into the world...
, from injury due to a disorder
Genetic disorder
A genetic disorder is an illness caused by abnormalities in genes or chromosomes, especially a condition that is present from before birth. Most genetic disorders are quite rare and affect one person in every several thousands or millions....
or congenital
Congenital disorder
A congenital disorder, or congenital disease, is a condition existing at birth and often before birth, or that develops during the first month of life , regardless of causation...
malady
Disease
A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...
.
Signs and symptoms
Brain injuries often create impairment or disabilityDisability
A disability may be physical, cognitive, mental, sensory, emotional, developmental or some combination of these.Many people would rather be referred to as a person with a disability instead of handicapped...
which can vary greatly in severity. In cases of serious brain injuries, the likelihood of areas with permanent disability
Disability
A disability may be physical, cognitive, mental, sensory, emotional, developmental or some combination of these.Many people would rather be referred to as a person with a disability instead of handicapped...
is great, including neurocognitive deficits, delusion
Delusion
A delusion is a false belief held with absolute conviction despite superior evidence. Unlike hallucinations, delusions are always pathological...
s (often specifically monothematic delusion
Monothematic delusion
A monothematic delusion is a delusional state that only concerns one particular topic. This is contrasted by what is sometimes called multi-thematic or polythematic delusions where the person has a range of delusions...
s), speech or movement problems, and mental handicap
Mental retardation
Mental retardation is a generalized disorder appearing before adulthood, characterized by significantly impaired cognitive functioning and deficits in two or more adaptive behaviors...
. There will also be personality changes. The most severe cases result in coma
Coma
In medicine, a coma is a state of unconsciousness, lasting more than 6 hours in which a person cannot be awakened, fails to respond normally to painful stimuli, light or sound, lacks a normal sleep-wake cycle and does not initiate voluntary actions. A person in a state of coma is described as...
or even persistent vegetative state
Persistent vegetative state
A persistent vegetative state is a disorder of consciousness in which patients with severe brain damage are in a state of partial arousal rather than true awareness. It is a diagnosis of some uncertainty in that it deals with a syndrome. After four weeks in a vegetative state , the patient is...
. Even a mild incident can have long term effects or cause symptoms to appear years later.
Mental fatigue is a common debilitating experience and may not be linked by the patient to the original (minor) incident. Narcolepsy and sleep disorders are common misdiagnoses.
Brain injury whether from stroke, alcohol abuse, traumatic brain injury, or vitamin B deficiency can sometimes result in Korsakoff's Psychosis, where the individual engages in confabulations. Confabulations involve the inability to separate daydream memory from real memory and the filling in of memory lapses with daydreams. Like all other symptoms of brain injuries, Korsakoff's Psychosis is often mis-diagnosed, in this case as schizophrenia.
Causes
Brain injuries occur due to a very wide range of conditions, illnessIllness
Illness is a state of poor health. Illness is sometimes considered another word for disease. Others maintain that fine distinctions exist...
es, injuries
Injury
-By cause:*Traumatic injury, a body wound or shock produced by sudden physical injury, as from violence or accident*Other injuries from external physical causes, such as radiation injury, burn injury or frostbite*Injury from infection...
, and as a result of iatrogenesis
Iatrogenesis
Iatrogenesis, or an iatrogenic artifact is an inadvertent adverse effect or complication resulting from medical treatment or advice, including that of psychologists, therapists, pharmacists, nurses, physicians and dentists...
(adverse effects of medical treatment). Possible causes of widespread (diffuse) brain damage include prolonged hypoxia
Hypoxia (medical)
Hypoxia, or hypoxiation, is a pathological condition in which the body as a whole or a region of the body is deprived of adequate oxygen supply. Variations in arterial oxygen concentrations can be part of the normal physiology, for example, during strenuous physical exercise...
(shortage of oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
), poison
Poison
In the context of biology, poisons are substances that can cause disturbances to organisms, usually by chemical reaction or other activity on the molecular scale, when a sufficient quantity is absorbed by an organism....
ing by teratogens (including alcohol
Alcohol
In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....
), infection
Infection
An infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...
, and neurological illness. Chemotherapy
Chemotherapy
Chemotherapy is the treatment of cancer with an antineoplastic drug or with a combination of such drugs into a standardized treatment regimen....
can cause brain damage to the neural stem cells and oligodendrocyte
Oligodendrocyte
Oligodendrocytes , or oligodendroglia , are a type of brain cell. They are a variety of neuroglia. Their main function is the insulation of axons in the central nervous system of some vertebrates...
cells that produce myelin
Myelin
Myelin is a dielectric material that forms a layer, the myelin sheath, usually around only the axon of a neuron. It is essential for the proper functioning of the nervous system. Myelin is an outgrowth of a type of glial cell. The production of the myelin sheath is called myelination...
. Common causes of focal or localized brain damage
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 the result of the same event; many traumatic brain injuries have aspects...
are physical trauma
Physical trauma
Trauma refers to "a body wound or shock produced by sudden physical injury, as from violence or accident." It can also be described as "a physical wound or injury, such as a fracture or blow." Major trauma can result in secondary complications such as circulatory shock, respiratory failure and death...
(traumatic brain injury
Traumatic brain injury
Traumatic brain injury , also known as intracranial injury, occurs when an external force traumatically injures the brain. TBI can be classified based on severity, mechanism , or other features...
, stroke
Stroke
A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...
, aneurysm
Aneurysm
An aneurysm or aneurism is a localized, blood-filled balloon-like bulge in the wall of a blood vessel. Aneurysms can commonly occur in arteries at the base of the brain and an aortic aneurysm occurs in the main artery carrying blood from the left ventricle of the heart...
, surgery
Surgery
Surgery is an ancient medical specialty that uses operative manual and instrumental techniques on a patient to investigate and/or treat a pathological condition such as disease or injury, or to help improve bodily function or appearance.An act of performing surgery may be called a surgical...
, other neurological disorder
Neurological disorder
A neurological disorder is a disorder of the body's nervous system. Structural, biochemical or electrical abnormalities in the brain, spinal cord, or in the nerves leading to or from them, can result in symptoms such as paralysis, muscle weakness, poor coordination, loss of sensation, seizures,...
), and heavy metals
Heavy metals
A heavy metal is a member of a loosely-defined subset of elements that exhibit metallic properties. It mainly includes the transition metals, some metalloids, lanthanides, and actinides. Many different definitions have been proposed—some based on density, some on atomic number or atomic weight,...
causing poisoning
Toxicity
Toxicity is the degree to which a substance can damage a living or non-living organisms. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a substructure of the organism, such as a cell or an organ , such as the liver...
including by mercury and its compounds of lead or blows to the back of skull.
Management
Various professions may be involved in the medical care and rehabilitationPhysical therapy
Physical therapy , often abbreviated PT, is a health care profession. Physical therapy is concerned with identifying and maximizing quality of life and movement potential within the spheres of promotion, prevention, diagnosis, treatment/intervention,and rehabilitation...
of someone who suffers impairment after a brain injury. Neurologist
Neurologist
A neurologist is a physician who specializes in neurology, and is trained to investigate, or diagnose and treat neurological disorders.Neurology is the medical specialty related to the human nervous system. The nervous system encompasses the brain, spinal cord, and peripheral nerves. A specialist...
s, neurosurgeons, and physiatrist
Physical medicine and rehabilitation
Physical medicine and rehabilitation , physiatry or rehabilitation medicine, is a branch of medicine that aims to enhance and restore functional ability and quality of life to those with physical impairments or disabilities. A physician having completed training in this field is referred to as a...
s are physician
Physician
A physician is a health care provider who practices the profession of medicine, which is concerned with promoting, maintaining or restoring human health through the study, diagnosis, and treatment of disease, injury and other physical and mental impairments...
s who specialise in treating brain injury. neuropsychologists
Neuropsychology
Neuropsychology studies the structure and function of the brain related to specific psychological processes and behaviors. The term neuropsychology has been applied to lesion studies in humans and animals. It has also been applied to efforts to record electrical activity from individual cells in...
(especially clinical neuropsychologists
Clinical neuropsychology
Clinical neuropsychology is a sub-field of psychology concerned with the cognitive function of individuals with neurological and psychiatric disorders. Neuropsychological assessment examines cognitive function in the broadest sense, including the behavioural, emotional, social and functional status...
) are psychologist
Psychologist
Psychologist is a professional or academic title used by individuals who are either:* Clinical professionals who work with patients in a variety of therapeutic contexts .* Scientists conducting psychological research or teaching psychology in a college...
s who specialise in understanding the effects of brain injury and may be involved in assessing the severity or creating rehabilitation
Rehabilitation (neuropsychology)
Rehabilitation of sensory and cognitive function typically involves methods for retraining neural pathways or training new neural pathways to regain or improve neurocognitive functioning that has been diminished by disease or traumatic injury....
strategies. Occupational therapists
Occupational therapy
Occupational therapy is a discipline that aims to promote health by enabling people to perform meaningful and purposeful activities. Occupational therapists work with individuals who suffer from a mentally, physically, developmentally, and/or emotionally disabling condition by utilizing treatments...
may be involved in running rehabilitation programs to help restore lost function or help re-learn essential skills. Registered nurse
Registered nurse
A registered nurse is a nurse who has graduated from a nursing program at a university or college and has passed a national licensing exam. A registered nurse helps individuals, families, and groups to achieve health and prevent disease...
s, such as those working in hospital intensive care unit
Intensive Care Unit
thumb|220px|ICU roomAn intensive-care unit , critical-care unit , intensive-therapy unit/intensive-treatment unit is a specialized department in a hospital that provides intensive-care medicine...
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
Glasgow Coma Scale
Glasgow Coma Scale or GCS is a neurological scale that aims to give a reliable, objective way of recording the conscious state of a person for initial as well as subsequent assessment...
used by other health professionals to quantify extent of orientation.
The effects of impairment or disability
Disability
A disability may be physical, cognitive, mental, sensory, emotional, developmental or some combination of these.Many people would rather be referred to as a person with a disability instead of handicapped...
resulting from brain injury may be treated by a number of methods, including medication
Medication
A pharmaceutical drug, also referred to as medicine, medication or medicament, can be loosely defined as any chemical substance intended for use in the medical diagnosis, cure, treatment, or prevention of disease.- Classification :...
, psychotherapy
Psychotherapy
Psychotherapy is a general term referring to any form of therapeutic interaction or treatment contracted between a trained professional and a client or patient; family, couple or group...
, neuropsychological rehabilitation
Rehabilitation (neuropsychology)
Rehabilitation of sensory and cognitive function typically involves methods for retraining neural pathways or training new neural pathways to regain or improve neurocognitive functioning that has been diminished by disease or traumatic injury....
, snoezelen
Snoezelen
Snoezelen or controlled multisensory Environment relates to the interdependence of both the space and the "client-centered" approach of the practitioner...
, surgery
Surgery
Surgery is an ancient medical specialty that uses operative manual and instrumental techniques on a patient to investigate and/or treat a pathological condition such as disease or injury, or to help improve bodily function or appearance.An act of performing surgery may be called a surgical...
, or physical implants such as deep brain stimulation
Deep brain stimulation
Deep brain stimulation is a surgical treatment involving the implantation of a medical device called a brain pacemaker, which sends electrical impulses to specific parts of the brain...
.
In the case of brain damage from traumatic brain injury
Traumatic brain injury
Traumatic brain injury , also known as intracranial injury, occurs when an external force traumatically injures the brain. TBI can be classified based on severity, mechanism , or other features...
, dexamethasone and/or Mannitol
Mannitol
Mannitol is a white, crystalline organic compound with the formula . This polyol is used as an osmotic diuretic agent and a weak renal vasodilator...
may be used.
Prognosis
Prognosis, or the likely progress of a disorder, depends on the nature, location and cause of the brain damage (see Traumatic brain injuryTraumatic brain injury
Traumatic brain injury , also known as intracranial injury, occurs when an external force traumatically injures the brain. TBI can be classified based on severity, mechanism , or other features...
).
In general, neuroregeneration can occur in the peripheral nervous system
Peripheral nervous system
The peripheral nervous system consists of the nerves and ganglia outside of the brain and spinal cord. The main function of the PNS is to connect the central nervous system to the limbs and organs. Unlike the CNS, the PNS is not protected by the bone of spine and skull, or by the blood–brain...
but is much rarer and more difficult to assist in the central nervous system
Central nervous system
The central nervous system is the part of the nervous system that integrates the information that it receives from, and coordinates the activity of, all parts of the bodies of bilaterian animals—that is, all multicellular animals except sponges and radially symmetric animals such as jellyfish...
(brain or spinal cord). However, in neural development in humans
Neural development in humans
The study of neural development draws on both neuroscience and developmental biology to describe the cellular and molecular mechanisms by which complex nervous systems emerge during embryonic development and throughout life....
, 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
Neuroplasticity is a non-specific neuroscience term referring to the ability of the brain and nervous system in all species to change structurally and functionally as a result of input from the environment. Plasticity occurs on a variety of levels, ranging from cellular changes involved in...
.
It is a common misconception that a brain injury sustained during childhood always has a better chance of successful recovery than similar injury acquired in adult life. It is contested that in recent studies, severe brain injuries inflicted upon children can be alleviated by the interaction of nicotinamide repropagation in nerve cells. However, the consequences of childhood injury may simply be more difficult to detect in the short term. This is because different cortical
Cerebral cortex
The cerebral cortex is a sheet of neural tissue that is outermost to the cerebrum of the mammalian brain. It plays a key role in memory, attention, perceptual awareness, thought, language, and consciousness. It is constituted of up to six horizontal layers, each of which has a different...
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 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.
See also
- Cerebral PalsyCerebral palsyCerebral palsy is an umbrella term encompassing a group of non-progressive, non-contagious motor conditions that cause physical disability in human development, chiefly in the various areas of body movement....
- EpilepsyEpilepsyEpilepsy is a common chronic neurological disorder characterized by seizures. These seizures are transient signs and/or symptoms of abnormal, excessive or hypersynchronous neuronal activity in the brain.About 50 million people worldwide have epilepsy, and nearly two out of every three new cases...
- Fetal alcohol syndromeFetal alcohol syndromeFetal alcohol syndrome is a pattern of mental and physical defects that can develop in a fetus in association with high levels of alcohol consumption during pregnancy. Current research also implicates other lifestyle choices made by the prospective mother...
- Frontal lobe injuryFrontal lobe injuryFrontal lobe injury is caused by a number of conditions such as trauma, meningitis, or even hypoxia , such as in drowning. The frontal lobe is an extremely vulnerable spot to injury due to its location at the front of the brain, and even minor trauma, such as a concussion, can cause permanent,...
- Head injuryHead injuryHead injury refers to trauma of the head. This may or may not include injury to the brain. However, the terms traumatic brain injury and head injury are often used interchangeably in medical literature....
- LobotomyLobotomyLobotomy "; τομή – tomē: "cut/slice") is a neurosurgical procedure, a form of psychosurgery, also known as a leukotomy or leucotomy . It consists of cutting the connections to and from the prefrontal cortex, the anterior part of the frontal lobes of the brain...
- Nerve injuryNerve injuryNerve injury is injury to nervous tissue. There is no single classification system that can describe all the many variations of nerve injury. Most systems attempt to correlate the degree of injury with symptoms, pathology and prognosis...
- Neurocognitive deficit
- NeurologyNeurologyNeurology is a medical specialty dealing with disorders of the nervous system. Specifically, it deals with the diagnosis and treatment of all categories of disease involving the central, peripheral, and autonomic nervous systems, including their coverings, blood vessels, and all effector tissue,...
- Primary and secondary brain injuryPrimary and secondary brain injuryPrimary and secondary brain injury are ways to classify the injury processes that occur in brain injury. In traumatic brain injury , primary injury occurs during the initial insult, and results from displacement of the physical structures of the brain. On the other hand, secondary injury occurs...
- Rehabilitation (neuropsychology)Rehabilitation (neuropsychology)Rehabilitation of sensory and cognitive function typically involves methods for retraining neural pathways or training new neural pathways to regain or improve neurocognitive functioning that has been diminished by disease or traumatic injury....
- Traumatic brain injuryTraumatic brain injuryTraumatic brain injury , also known as intracranial injury, occurs when an external force traumatically injures the brain. TBI can be classified based on severity, mechanism , or other features...