Head Injury
Meaning
A head injury is a broad term that describes a vast array of injuries that occur to the scalp, skull, brain, and underlying tissue and blood vessels in the head.
Head injuries are also commonly referred to as brain injury, or traumatic brain injury (TBI), depending on the extent of the head trauma.
Johns Hopkins
Epidemiology
Global – The worldwide incidence of pediatric TBI ranges broadly and varies greatly by country, with most reporting a range between 47 and 280 per
100,000 children. After the age of 3, male children suffered higher rates of TBI than females. (Dewan, Mummareddy, Wellons, & Bonfield 2016)
India – Retrospective record analysis of children (aged ≤ 16 years) with traumatic brain injury presenting to an apex-trauma-center in North India over 4
years was done. Of more than 15 000 patients with a suspected head injury, 4833 were children ≤16 years old. Of these, 1074 were admitted to the inpatient
department; 65% were boys with a mean age at presentation being 6.6 years. (Madaan et al., 2021)
Etiology
The most common causes of head injury in children are falls, being struck by or striking an object with one’s head, and motor vehicle accidents, in that order
(Centers for Disease Control and Prevention, 2017).
Assaults are the leading cause of death from traumatic brain injury in children 4 years of age or younger (Taylor, Bell, Breiding, et al., 2017)
Many of the physical characteristics of children predispose them to craniocerebral trauma. For example, infants are often left unattended on beds, in high
chairs, and in other places from which they can fall. Because the head of an infant or toddler is proportionately large and heavy in relation to other body parts,
it is the most likely to be injured.
Incomplete motor development contributes to falls at young ages, and the natural curiosity of children increase their risk for injury.
,Pathophysiology
The pathology of brain injury is directly related to the force of impact.
Intracranial contents (brain, blood, CSF) are damaged because the force is too great to be absorbed by the skull and musculoligamentous support of
the head.
Although nervous tissue is delicate, it usually requires a severe blow to cause significant damage.
A child’s response to head injury is different from that of adults. The larger head size in proportion to body size and insufficient musculoskeletal
support render the very young child particularly vulnerable to acceleration-deceleration injuries.
Primary head injuries are those that occur at the time of trauma and include skull fractures, contusions, intracranial hematomas, and diffuse injuries.
Subsequent complications include hypoxic brain injury, increased ICP, and cerebral edema.
The predominant feature of a child’s brain injury is the diffuse amount of swelling that occurs.
Hypoxia and hypercapnia threaten the energy requirements of the brain and increase CBF.
The added volume across the BBB along with the loss of autoregulation exacerbates cerebral edema.
Pressure inside the skull that is greater than arterial pressure results in inadequate perfusion.
Because the cranium of very young children has the ability to expand and the thin skull is more compliant, they may tolerate increases in ICP better than older
children and adults.
Physical forces act on the head through acceleration, deceleration, or deformation.
Acceleration or deceleration is more descriptive of the circumstances responsible for most head injuries.
When the stationary head receives a blow, the sudden acceleration causes deformation of the skull and mass movement of the brain.
Continued movement of the intracranial contents allows the brain to strike parts of the skull (e.g., the sharp edges of the sphenoid or the irregular surface of
the anterior fossa) or the edges of the tentorium.
, Although the brain volume remains unchanged, significant distortion and cavitation occur as the brain changes shape in response to the force transmitted from
the impact to the skull.
This deformation can cause bruising at the point of impact (coup) or at a distance as the brain collides with the unyielding surfaces opposite or far removed
from the point of impact (contrecoup).
When a moving head strikes a stationary surface, such as during a fall, sudden deceleration occurs and causes the greatest cerebral injury at the point of
impact. Deceleration is responsible for most severe brainstem injuries.
Children with an acceleration-deceleration injury demonstrate diffuse generalized cerebral swelling produced by increased blood volume or by a
redistribution of cerebral blood volume (cerebral hyperemia) rather than by the increased water content (edema).
Another effect of brain movement is shearing forces, which are caused by unequal movement or different rates of acceleration at various levels of the brain.
A shearing force may tear small arteries that travel from the cerebral surfaces through the meninges to the dural sinuses and cause subdural hemorrhages.
Shearing or stretching effects can also be transmitted to nerve fibers. Maximum stress from the shearing force occurs at the interface between structures of
different density so that gray matter (cell body) rapidly accelerates, whereas the white matter (axons) tends to lag behind.
Although maximum shearing forces are at the cerebral surface and extend toward the center of rotation within the brain, the most serious effects are often in
the area of the brainstem.
Severe compression of the skull can cause the brain to be forced through the tentorial opening and produce irreparable damage to the brainstem.
A GCS value of 8 or less in pediatric patients indicates severe injury and requires aggressive therapeutic management.
Three out of four children with a score of 3 or 4 will be severely disabled, be in a persistent vegetative state, or die within a year of their injury.
Types of head injuries
Meaning
A head injury is a broad term that describes a vast array of injuries that occur to the scalp, skull, brain, and underlying tissue and blood vessels in the head.
Head injuries are also commonly referred to as brain injury, or traumatic brain injury (TBI), depending on the extent of the head trauma.
Johns Hopkins
Epidemiology
Global – The worldwide incidence of pediatric TBI ranges broadly and varies greatly by country, with most reporting a range between 47 and 280 per
100,000 children. After the age of 3, male children suffered higher rates of TBI than females. (Dewan, Mummareddy, Wellons, & Bonfield 2016)
India – Retrospective record analysis of children (aged ≤ 16 years) with traumatic brain injury presenting to an apex-trauma-center in North India over 4
years was done. Of more than 15 000 patients with a suspected head injury, 4833 were children ≤16 years old. Of these, 1074 were admitted to the inpatient
department; 65% were boys with a mean age at presentation being 6.6 years. (Madaan et al., 2021)
Etiology
The most common causes of head injury in children are falls, being struck by or striking an object with one’s head, and motor vehicle accidents, in that order
(Centers for Disease Control and Prevention, 2017).
Assaults are the leading cause of death from traumatic brain injury in children 4 years of age or younger (Taylor, Bell, Breiding, et al., 2017)
Many of the physical characteristics of children predispose them to craniocerebral trauma. For example, infants are often left unattended on beds, in high
chairs, and in other places from which they can fall. Because the head of an infant or toddler is proportionately large and heavy in relation to other body parts,
it is the most likely to be injured.
Incomplete motor development contributes to falls at young ages, and the natural curiosity of children increase their risk for injury.
,Pathophysiology
The pathology of brain injury is directly related to the force of impact.
Intracranial contents (brain, blood, CSF) are damaged because the force is too great to be absorbed by the skull and musculoligamentous support of
the head.
Although nervous tissue is delicate, it usually requires a severe blow to cause significant damage.
A child’s response to head injury is different from that of adults. The larger head size in proportion to body size and insufficient musculoskeletal
support render the very young child particularly vulnerable to acceleration-deceleration injuries.
Primary head injuries are those that occur at the time of trauma and include skull fractures, contusions, intracranial hematomas, and diffuse injuries.
Subsequent complications include hypoxic brain injury, increased ICP, and cerebral edema.
The predominant feature of a child’s brain injury is the diffuse amount of swelling that occurs.
Hypoxia and hypercapnia threaten the energy requirements of the brain and increase CBF.
The added volume across the BBB along with the loss of autoregulation exacerbates cerebral edema.
Pressure inside the skull that is greater than arterial pressure results in inadequate perfusion.
Because the cranium of very young children has the ability to expand and the thin skull is more compliant, they may tolerate increases in ICP better than older
children and adults.
Physical forces act on the head through acceleration, deceleration, or deformation.
Acceleration or deceleration is more descriptive of the circumstances responsible for most head injuries.
When the stationary head receives a blow, the sudden acceleration causes deformation of the skull and mass movement of the brain.
Continued movement of the intracranial contents allows the brain to strike parts of the skull (e.g., the sharp edges of the sphenoid or the irregular surface of
the anterior fossa) or the edges of the tentorium.
, Although the brain volume remains unchanged, significant distortion and cavitation occur as the brain changes shape in response to the force transmitted from
the impact to the skull.
This deformation can cause bruising at the point of impact (coup) or at a distance as the brain collides with the unyielding surfaces opposite or far removed
from the point of impact (contrecoup).
When a moving head strikes a stationary surface, such as during a fall, sudden deceleration occurs and causes the greatest cerebral injury at the point of
impact. Deceleration is responsible for most severe brainstem injuries.
Children with an acceleration-deceleration injury demonstrate diffuse generalized cerebral swelling produced by increased blood volume or by a
redistribution of cerebral blood volume (cerebral hyperemia) rather than by the increased water content (edema).
Another effect of brain movement is shearing forces, which are caused by unequal movement or different rates of acceleration at various levels of the brain.
A shearing force may tear small arteries that travel from the cerebral surfaces through the meninges to the dural sinuses and cause subdural hemorrhages.
Shearing or stretching effects can also be transmitted to nerve fibers. Maximum stress from the shearing force occurs at the interface between structures of
different density so that gray matter (cell body) rapidly accelerates, whereas the white matter (axons) tends to lag behind.
Although maximum shearing forces are at the cerebral surface and extend toward the center of rotation within the brain, the most serious effects are often in
the area of the brainstem.
Severe compression of the skull can cause the brain to be forced through the tentorial opening and produce irreparable damage to the brainstem.
A GCS value of 8 or less in pediatric patients indicates severe injury and requires aggressive therapeutic management.
Three out of four children with a score of 3 or 4 will be severely disabled, be in a persistent vegetative state, or die within a year of their injury.
Types of head injuries
