Criteria for urgent CT scan and consultation with a neurosurgical unit

The presence of one or more of the following:

Criteria for hospital admission after recent head injury

The presence of one or more of the following:

Skull radiography after recent head injury

CT scan is the preferred option. A skull radiograph images the skull but provides no information about the brain and therefore is of little use. All patients suffering a significant head injury should have a CT scan, which in most cases will identify any skull fracture.

Primary

This is the damage caused as an immediate result of trauma. It results in contusions, lacerations or diffuse brain damage. Treatment cannot reverse primary brain injury.

Secondary

This develops as a result of complications such as intracranial bleeding, cerebral hypoxia, cerebral oedema and infection. The prevention, recognition and treatment of these secondary complications is the mainstay of treatment of the patient with head injuries.

Emergency

Evaluate CNS injury

Assess the level of consciousness as this is the most significant factor after head injury. Use GCS (→ Table 4.1) and check pupillary reactions. Pupillary changes may indicate brain swelling or compression. Pressure on a cerebral hemisphere causes the third nerve on that side to be stretched over the edge of the tentorium. The resultant paralysis of the nerve allows unopposed action of the dilator pupillae under the control of the sympathetic nervous system and the pupils dilate. There is also loss of light reaction of the pupil on the affected side. If compression continues, the contralateral third nerve is compressed and the opposite pupil also dilates and is fixed to light. Bilateral fixed dilated pupils in a patient with a head injury are a grave prognostic sign and recovery is rare. Pupillary changes are always late signs (‘undertaker signs’), and are always preceded by an alteration in conscious level caused by raised intracranial pressure. Direct blows to the eyes can cause dilated pupils in patients without severe brain injury.

CNS examination

This may be difficult in the unconscious patient. Observe the pattern of limb movement in response to painful stimuli. Progressive unilateral weakness or focal epilepsy may be helpful localizing signs. Obtain a history from witnesses to the event, e.g. speed of impact, height of fall, state of crash helmet.

Check for CSF rhinorrhoea or otorrhoea

Check for these signs. Periorbital bruising and retromastoid bruising imply basal skull fracture.

Scalp lacerations or depressed fractures

Check these using a gloved finger. If in doubt, perform a CT scan.

Assess amnesia

Post-traumatic amnesia (loss from time of the injury) gives an assessment of the severity of the injury. Retrograde amnesia correlates poorly with the severity of the injury. Post-traumatic amnesia of >1 week signifies severe damage. Patients seen initially may appear fully conscious and orientated. Do not make allowances when assessing. They are often amnesic of events in A&E when asked at a later date.

Summary

The emphasis in the management of head injuries is on damage to the underlying structures rather than on any skull fracture per se. CT scanning is the investigation of choice for patients with head injury and no patient with a significant head injury should be admitted to a hospital A&E department that does not have immediate 24-hour access to CT scanning.

Extradural

This results from bleeding between the bone and the dura. It is most likely to occur when a fracture occurs in the temporal region crossing the middle meningeal artery. It may occasionally occur without a fracture. Usually low-speed injury.

Subdural

Intracerebral

This occurs as a result of primary brain injury but may expand causing secondary brain damage. It may extend into the ventricles. A discrete haematoma may require craniotomy if the patient’s condition deteriorates. Always consider other primary causes for the intracerebral haematoma causing collapse and secondary head injury.