Head Trauma in children
Trauma is the second leading cause of death in children less than 15 years of age and head injury is responsible for 20% of these deaths. The outcome in the children depends on the severity of the injury as well as management. Children have a large number of productive years ahead - it is imperative that these children require utmost care and attention. The mechanism of injury in children is distinct from adults with common causes being falls (35%), recreational activities (29%) and traffic accidents (24%). There is also age specific variation with child abuse seen frequently in children less than 2 years of age. Falls are a major cause of head injury in children less than 3 years. Road traffic accidents account for larger numbers as the age of the child increases.
Children as mini adults and treat them similarly. The immature skull has different mechanical properties and the child’s brain is undergoing maturation and development and. The newborn’s skull has pliable thin bones which can significantly deform.The pliability of the skull makes it more vulnerable to injury especially diffuse injury. The child’s brain is much larger in proportion to the body as compared to adults - the newborn’s brain constitutes 15% of body weight compared to 3% in the adult. The relatively larger size of the brain of a child in comparison to the body makes it more vulnerable to injury.
Head injury could be primary or secondary. The primary injury is the immediate Contact forces may result in fractures, localized contusions and hematoma ,hemorrhages and diffuse injury. Secondary injury results from an array of reactive events which follow the primary event and can worsen the initial injury or cause new injury to brain. These events include hypoxia, hypotension, metabolic alterations, fluid and electrolyte imbalance, brain edema, seizures, local and systemic infections etc The secondary injury are preventable and this constitutes an important aim in the management of the head injured child. Various pathologies may be seen in head injured patients.
Contusions
The Contusions may be at the site of impact[coup], counter coup. Contusions associated with tears in the cortical surface are called lacerations Concussion is a clinical syndrome characterized by a transient and reversible impairment of consciousness which does not leave any residual deficit. Rotational forces are responsible for causing a Diffuse Axonal Injury characterized by stretch and shearing injury to the axons and the myelin sheath at the grey white matter junction, in the corpus callosum, dorsolateral pons and superior cerebellar peduncle. Head injury could also be classified as mild, moderate or severe based on the Glasgow Coma Scale (GCS) of 13 to 15, 9 to 12 and 3 to 8 respectively. In children mild injuries account for 80% of all head injuries whereas moderate and severe injuries constitute 10% each. Radiological assessment includes Skull X-Rays and CT scan.
Except for a few children, most children with mild head injury make remarkable recoveries and full recovery is the norm. The major concern in these patients is parental anxiety and overprotection. The overall focus of care in moderate and severe head injuries would be to prevent brain ischemia by controlling ICP and removing focal symptomatic mass lesions.
Skull Fractures:
Skull fractures are common in children with the vast majority being linear skull fractures. The parietal bone is the most common site and patients present with pain and swelling. Subgaleal and subperiosteal hematomas may occur with the fracture and in neonates and infants may be substantial enough to require blood transfusion. Depressed fractures may require surgery if associated with a dural tear or if compound or if large underlying contusion / hematoma. There is no evidence that elevation of a simple depressed fracture would improve neurological outcome or prevent seizures Compound depressed fractures should be explored because of concerns of infection. Depressed fractures in frontal area may need to be elevated for cosmetic purposes. Infants are prone to Ping-pong fracture.
Mass Lesion:
Intracranial hematoma are serious pathology and require urgent attention. Extradural hematomas are fairly uncommon in children because the dura is tightly adherent to the periosteum. Also the groove of the middle meningeal artery is shallow and therefore the artery is less prone to tear with injury. Almost all extradural hematomas are associated with a fracture. Subdural hematoma are second common and may be associated with rotational forces and assoacited brain injury. Intracerebral hematomas and contusions occur with increasing frequency with increasingage and occur as a result of acceleration – deceleration injury. Management of these mass lesions would depend upon the clinical condition of the child and the size of the lesions.
Growing Skull Fractures:
This is an uncommon condition found in very young children with a growing brain. Also known as Leptomeningeal Cyst and Craniocerebral Erosion. It happens when there is fracture with a dural tear and an outward driving force such as a growing brain, a cyst or hydrocephalus. The pulsations of the brain against the bone edges and the pressure exerted result in erosion of the bone edge and subsequent eversion. The underlying brain gets attached to the dura an This results in the development of and prevents from fracture from healing.Epileptic focus often with intractable seizures and also of progressive neurological deficit. All such cases need surgery as the fractures never heal and the clinical and pathologic changes are progressive
Non Accidental Injury:
Non accidental injury is injury deliberately inflicted on the child. Also know ‘Shaken Baby syndrome’. This resulted from a relatively large infant head pivoting back and forth on the cervical spine They are brought to the hospital either with non specific complaints like lethargy, irritability, unresponsiveness or even apnea or with a history of a minor injury - usually fall from short height. Also associated with soft tissue and skeletal injury in different stages of healing. Fractures are bilateral, multiple or stellate. Retinal hemorrhages occur in 65 – 95% . The outcome of such injuries depends upon the condition of the child on presentation.
Birth Injuries:
Birth injuries could be due to mechanical forces during childbirth or could result from hypoxic / ischemic insults. The mechanical forces could result in scalp injuries, fractures or intracranial hematoma. Scalp injuries in the newborn could be of three types – Caput Succedaneum, Subgaleal hematoma and Cephalhematoma. Caput is seen in almost all children and involves edema of the outer layers of the scalp. It usually resolves in a day or two. Subgaleal hematoma is rare but potentially life threatening because the large subgaleal space can accommodate the whole blood volume of a neonate. The cephalhematoma is underneath the periosteum and is limited by the cranial sutures.
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