A traumatic blow to the head causes a head injury. The blow is usually sudden and forceful, such as a fall, motor vehicle accident, or punch to the head. If the blow causes an acceleration-deceleration or coup-countercoup injury, then a cerebral contusion results. Acceleration-deceleration injuries can occur directly beneath the site of impact when the brain rebounds against the skull from the force of a blow (a beating with a blunt instrument, for example), when the force of the blow drives the brain against the opposite side of the skull, or when the head is hurled forward and stopped abruptly (as when a driver’s head strikes the windshield). The brain continues moving and slaps against the skull (acceleration) and rebounds (deceleration).

A concussion usually causes no significant anatomic brain injury. Seizures, persistent vomiting, or both may occur. Rarely, a concussion leads to intracranial hemorrhage (subdural, epidural, or parenchymal).

A cerebral contusion can cause intracranial hemorrhage or hematoma if the injury causes the brain to strike against bony prominences inside the skull (especially the sphenoidal ridges). Residual headaches and vertigo may complicate recovery. Secondary effects, such as brain swelling, may accompany serious contusions, resulting in increased intracranial pressure (ICP) and herniation.

Skull fractures can lead to infection, intracerebral hemorrhage and hematoma, brain abscess, and increased ICP from edema. Recovery from the injury can be further complicated by residual effects of the injury, such as seizure disorders, hydrocephalus, and organic mental syndrome.

The patient’s history (obtained from the patient, his family, eyewitnesses, or emergency personnel) reveals a traumatic injury to the head. A period of unconsciousness may follow the trauma. If unconscious, the patient may appear pale and motionless. If conscious, he may appear
drowsy or easily disturbed by any form of stimulation, such as noise or light.

If the patient has a concussion, a family member or friend may report behavioral changes, saying that the patient is behaving out of character. The patient usually complains of dizziness, nausea, and severe headache. He may also exhibit anterograde and retrograde amnesias. In retrograde amnesia, the patient can’t recall what happened immediately after the injury and has difficulty recalling events that led up to it. Typically, he repeats the same questions. The presence of anterograde amnesia and the duration of retrograde amnesia reliably correlate with the injury’s severity. A conscious patient with a cerebral contusion may become agitated and even violent. If he has a skull fracture, he may complain of a persistent, localized headache. Depending on the type and location of the fracture, he may appear dazed, anxious, or agitated.

Your assessment findings will vary, depending on the type and location of the head injury. Your examination should focus on evaluating the patient’s level of consciousness (LOC), pupillary responses, and strength of extremities. Vital signs aren’t good indicators of neurologic status and don’t correlate specifically with the type of injury unless the brain stem is involved.

Because scalp wounds usually accompany a cerebral contusion or skull fracture, scalp inspection may reveal abrasions, contusions, lacerations, or avulsions. If the scalp was lacerated or torn away, profuse bleeding may occur, although it isn’t heavy enough to induce hypovolemic shock. However, the patient may be in shock from other injuries or from medullary failure in the case of a severe head injury.

Other inspection findings in a patient with a skull fracture may include bleeding in the nose, pharynx, or ears; under the conjunctivae; under the periorbital skin (raccoon’s eyes caused by bruising around the mastoid); and behind the eardrum. You may also note Battle’s sign. Inspection of the ears and nose may reveal cerebrospinal fluid (CSF) and brain tissue leakage. (Leakage may be found on the patient’s pillowcase or bed linens.) Basilar fractures of the skull commonly produce hemorrhage from these areas. Red-tinged CSF drainage strongly suggests brain injury.

Palpation of the skull may reveal tenderness or hematomas in a patient with a concussion. It may reveal palpable fractures, areas of swelling, and possibly hematoma formation in a patient with a skull fracture. A vault fracture commonly causes soft-tissue swelling near the site, making other fractures hard to detect without X-rays.

A neurologic assessment usually produces normal findings in a patient with a concussion and abnormal findings in a patient with a cerebral contusion or skull fracture. A patient with a cerebral contusion may display hemiparesis, decorticate or decerebrate posturing, and unequal pupillary response. With effort, you may be able to rouse an unconscious patient temporarily. If the acute stage has passed, you may find that the patient has returned to a relatively alert state, perhaps with temporary aphasia, slight hemiparesis, or unilateral numbness.