Skull fractures may be simple (closed) or compound (open) and may or may not displace bone fragments. Skull fractures are further described as linear, comminuted, or depressed. A linear fracture is a common hairline break, without displacement of structures; a comminuted fracture splinters or crushes the bone into several fragments; a depressed fracture pushes the bone toward the brain.
Because possible damage to the brain is the first concern, rather than the fracture itself, a skull fracture is considered a neurosurgical condition.
In children, the skull’s thinness and elasticity allow a depression without a fracture (a linear fracture across a suture line increases the possibility of epidural hematoma).
Skull fractures are also classified according to location, such as a cranial vault fracture; a basilar fracture is at the base of the skull and involves the cribriform plate and the frontal sinuses. Because of the danger of grave cranial complications and meningitis, basilar fractures are usually far more serious than vault fractures.
Like concussions and cerebral contusions or lacerations, skull fractures invariably result from a traumatic blow to the head. Motor vehicle accidents, bad falls, and severe beatings (especially in children) top the list of causes.
Signs and symptoms
Skull fractures are often accompanied by scalp wounds—abrasions, contusions, lacerations, or avulsions. If the scalp has been lacerated or torn away, bleeding may be profuse because the scalp contains many blood vessels.
Bleeding can occasionally be heavy enough to induce hypovolemic shock. The patient may also be in shock from other injuries or from medullary failure in severe head injuries.
Linear fractures that are associated only with concussion don’t produce loss of consciousness. They require evaluation, but not definitive treatment.
A fracture that results in cerebral contusion or laceration, however, may cause the classic signs of brain injury: agitation and irritability, loss of consciousness, changes in respiratory pattern (labored respirations), abnormal deep tendon reflexes, and altered pupillary and motor response.
If the patient with a skull fracture remains conscious, he’s apt to complain of a persistent, localized headache. A skull fracture also may result in cerebral edema, which may cause compression of the reticular activating system, cutting off the normal flow of impulses to the brain and resulting in possible respiratory distress. The patient may experience an altered level of consciousness (LOC), progressing to unconsciousness or even death.
When jagged bone fragments pierce the dura mater or the cerebral cortex, skull fractures may cause subdural, epidural, or intracerebral hemorrhage or hematoma. With the resulting space-occupying lesions, clinical findings may include hemiparesis, unequal pupils, dizziness, seizures, projectile vomiting, decreased pulse and respiratory rates, and progressive unresponsiveness.
Sphenoidal fractures may also damage the optic nerve, causing blindness. Temporal fractures may cause unilateral deafness or facial paralysis.