The scalp is richly vascularized and, if injured, can bleed profusely. This can lead to hemodynamically significant blood loss from relatively small lacerations, especially in infants and very young children. Carefully explore open scalp wounds for skull integrity, depressions, or foreign bodies. The presenting sign of a subgaleal hematoma is an extensive soft-tissue swelling that occurs several hours or days after the traumatic event and is commonly associated with a skull fracture. A subgaleal hematoma can persist for several days to weeks.
Linear nondepressed skull fractures occur at the point of impact. The presence of a skull fracture indicates a significant blow to the head, and children with skull fractures are more likely to have an associated intracranial injury. However, the absence of a skull fracture does not exclude the presence of intracranial injury.5 “Growing fractures” are unique to infants and young children. They may occur after a skull fracture in children younger than 2 years of age when associated with a dural tear. Rapid brain growth post-injury may be associated with the development of a leptomeningeal cyst, which is an extrusion of cerebrospinal fluid or brain tissue through the dural defect. Thus, children younger than 2 years with a skull fracture require follow-up to detect a growing fracture.
Basilar skull fractures typically occur at the petrous portion of the temporal bone, although they may occur anywhere along the base of the skull. Clinical signs suggesting a basilar skull fracture include hemotympanum, cerebrospinal fluid otorrhea, cerebrospinal fluid rhinorrhea, periorbital ecchymosis (raccoon eyes), or postauricular ecchymosis (Battle's sign). Radiologic diagnosis often requires detailed CT imaging of the temporal bone, as plain skull radiographs or routine head CT scans may not be diagnostic.
Epidural hematomas occur more commonly in older children than in infants and toddlers.6 Most occur in combination with a temporal skull fracture and meningeal artery bleeding; the remainder are venous in origin. They may be life-threatening, but prompt diagnosis and surgical intervention make an excellent outcome possible. Signs and symptoms include headache, vomiting, and altered mental status, which may progress to signs and symptoms of uncal herniation with pupillary changes and hemiparesis. Patients classically present with an initial lucid period followed by a rapid deterioration in mental status as the hemorrhage increases in size (Fig. 23-2).
Epidural hematoma with midline shift.
Acute subdural hematomas occur more commonly than epidural hematomas in children.2 Acute interhemispheric subdural hematomas, which occur more often in infants and young children, may be caused by shaking/impact injuries of abuse. Subdural hematomas usually result from tearing of the bridging veins and typically occur over the cerebral convexities. Subdural hematomas are often associated with more diffuse brain injury. They may progress more slowly than epidural bleeds, with symptoms commonly including irritability, vomiting, and alterations in mental status.
Parenchymal contusions are bruises or tears of brain tissue. Bony irregularities of the skull cause these cerebral contusions as the brain moves within the skull. A coup injury occurs at the site of impact, whereas a contrecoup injury occurs at a site remote from the impact. Intraparenchymal hemorrhages may also occur from shearing injury or penetrating wounds. They often occur in association with intracranial hematomas or skull fractures. Signs and symptoms may include decreased level of consciousness, focal neurologic findings, and seizures.
Penetrating injuries result from sharp object penetration or gunshot wounds. Extensive brain injury is common and severity depends on the path of the object and location and degree of associated hemorrhage.
A concussion is defined as a rapid onset of short-lived neurologic dysfunction with or without loss of consciousness following a traumatic event.7 Concussions occur in the absence of abnormalities on standard neuroimaging. Symptoms resolve spontaneously although a small number of concussion patients will have symptoms that persist for a prolonged period as a postconcussive syndrome.7,8 Symptoms may include amnesia, vomiting, headache, dizziness, visual changes, instability of balance, as well as cognitive impairments, emotional changes, and abnormal sleep patterns.
Diffuse brain swelling occurs more often in children than in adults. The swelling usually results from a shearing or acceleration–deceleration injury. Prolonged coma or death may occur.
Nonaccidental trauma in infants and young children may result in the constellation of subdural hematoma, subarachnoid hemorrhage, and localized or diffuse brain edema (Fig. 23-3). Retinal hemorrhages, rib fractures, long-bone fractures, and external signs of injury may also be present. Common symptoms of nonaccidental traumatic brain injury in infants may include lethargy, vomiting, irritability, seizures, apnea, and severe alteration in consciousness.9,10
Right-sided subdural hematoma with associated midline shift and right hemispheric edema in an infant with nonaccidental head trauma.