Head Trauma



Head Trauma


Oluwakemi B. Badaki-Makun

Joel A. Fein



INTRODUCTION

Head injury in children accounts for up to 650,000 emergency department visits, 95,000 hospitalizations, and 7,400 deaths per year. It is the most significant cause of morbidity and mortality in pediatric trauma patients. The highest injury rates are found in children <4 years. Brain injuries can be subdivided into primary and secondary injuries. Primary injuries occur as a result of a mechanical damage at the time of insult and can be from direct trauma to the brain or shear forces experienced by the neuronal axons as a result of acceleration-deceleration injury. These injuries are usually irreversible. Fatal or irreversible injury is usually a sequela of neuronal cell death and vascular disruption during the first few milliseconds of impact. Secondary brain injuries result from subsequent pathophysiologic changes such as hypoperfusion, hypoxia, edema, and metabolic derangements. The only injuries that are reversible with therapy are those with secondary effects on the brain and blood vessels, such as cerebral edema and impaired glucose and oxygen delivery to the neurons.


DIFFERENTIAL DIAGNOSIS LIST


Focal Injuries



  • Scalp lacerations


  • Hematoma (subgaleal, subdural, epidural)


  • Cerebral contusion


  • Fractures


Diffuse Injuries



  • Concussion syndrome


  • Diffuse axonal injury


  • Increased intracranial pressure (ICP)


DIFFERENTIAL DIAGNOSIS DISCUSSION


Scalp Lacerations

Scalp lacerations are common findings in patients with head injuries. Blood loss can be extensive, especially in infants and young children, given the high vascularity of the scalp. The physician should apply direct pressure to stop local bleeding, carefully assess the depth of the wound, and evaluate it for retained foreign bodies. In addition, the integrity of the galea aponeurotica (a tendinous sheath located just above the periosteum) should be evaluated; attention to careful reapproximation of this layer often results in better hemostasis and easier closure of the
laceration. Finally, the physician should search for skull fractures or “step-offs” (dents).


Hematomas

Hematoma caused by head injury may exist outside of the confines of the skull (e.g., cephalohematoma, subgaleal hematoma) or inside the skull (e.g., epidural or subdural hematoma). Intracranial lesions may require neurosurgical intervention, whereas extracranial lesions rarely require any treatment other than supportive care.


Cephalohematoma

Newborn infants commonly incur a cephalohematoma, in which blood collects between the periosteum and the table of the skull and is therefore prevented from spreading past the midline. This type of injury is common in traumatic deliveries.


Subgaleal Hematoma

A posttraumatic, well-circumscribed “lump” on an older child’s head usually represents a subgaleal hematoma.


Epidural and Subdural Hematomas

Epidural hematomas are less often associated with underlying brain injury than are subdural hematomas (Table 37-1).


Subarachnoid Hemorrhage

Common in more severely injured patients, subarachnoid hemorrhage (SAH) results from shearing of small vessels in the pia mater. It is usually associated with other intracranial injuries. Due to the location of the bleed, SAH causes meningeal irritation and the clinical symptoms can mimic meningitis.


Cerebral Contusions and Lacerations

Cerebral contusions are bruises of the cortex and can occur as a coup injury (at the contact location) or as a contre-coup injury (rebounding, on the opposite side). Late intraparenchymal hematomas may occur.

Cerebral lacerations usually result from penetrating injury to the brain or from a depressed skull fracture. The clinical manifestations are more often a result of the associated concussion and the underlying brain injury than of the focal lesions themselves.


Skull Fractures

A significant proportion of children seen in emergency departments with head injury have skull fractures. Infants and children with trauma to the parietal area are at higher risk.


Linear Skull Fractures

Linear skull fractures comprise 75% to 90% of all skull fractures. Usually no treatment is necessary. However, if the fracture is located over a vascular structure (e.g., the middle meningeal artery), there is an increased incidence of epidural
hemorrhage. Diastatic (“growing”) fractures can develop when meninges get caught between the bone edges and continue to separate them.








TABLE 37-1 Epidural Versus Acute Subdural Hematoma

Epidural Hematoma

Subdural Hematoma


Common mechanism

Blunt direct trauma, frequently to parietal or temporal regions, lower forces

Acceleration-deceleration injury, direct trauma, higher forces


Etiology

Arterial or venous (bleed between skull and dura)

Venous (bridging veins between dura and arachnoid membranes)


Incidence

Uncommon

Common


Peak age

Usually >2 yr

Usually >1 yr, peak at 6 mo


Location

Unilateral, commonly parietal

75% Bilateral, diffuse, over cerebral hemispheres


Skull fracture

Common

Uncommon


Associated seizures

Uncommon

Common


Retinal hemorrhages

Rare

Common


Decreased level of consciousness

Common

Almost always (50% present in coma)


Mortality

Rare

Uncommon


Morbidity in survivors

Low

High, due to associated underlying brain injury


Other clinical findings

Dilated ipsilateral pupil, contralateral hemiparesis

Decreased level of consciousness

Period of lucidity prior to acute decompensation and rapid progression to herniation (only 20%)

Headaches, irritability, emesis


Onset

Acute

Acute (within 24 hr), subacute (within 1 d to 2 wk), or chronic (after 2 wk)


Findings on computed tomography

Lentiform “lens-shaped,” usually not crossing suture lines

Lunar “crescent shaped,” often not crossing midline (due to falx cerebri)

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Sep 14, 2016 | Posted by in PEDIATRICS | Comments Off on Head Trauma

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