Head injury

This article particularly refers to the National Institute for Health and Care Excellence (NICE).¹

What is a head injury?²

Head injury is defined as any trauma to the head other than superficial injuries to the face. Head injury can arise from blunt or penetrating trauma and result in:

• Direct injury at the impact site.

• Indirect injury may also be caused by movement of the brain within the skull, leading to contusions on the opposite side of the head from the impact, or disruptive injuries to axons and blood vessels from shearing or rotational forces as the head is accelerated and decelerated after the impact.

Traumatic brain injury

Traumatic brain injury occurs when head injury results in a disturbance of normal brain function. Traumatic brain injury can be categorised as mild (concussion), moderate, or severe. Traumatic brain injury may also be categorised as:

• Primary (damage occurring at the time of impact).

• Secondary (injury as a result of neurophysiological and anatomical changes minutes to days following primary insult - eg, from cerebral oedema, haematoma or increased intracranial pressure).

How common is head injury? (Epidemiology)²

• The incidence of head injury is difficult to assess as it varies according to the study definitions used and the point in the care pathway where people with head injury are assessed.

• Approximately 1.4 million people attend emergency departments in England and Wales each year with a recent head injury. 33–50% of these are children aged under 15 years. Approximately 200,000 people are admitted to hospital each year following head injury.

• About 90% of people attending emergency departments with a head injury have a minor head injury.

• One UK survey of children aged less than 15 years who were admitted to hospital found that the peak prevalence of hospital admission for head injury was in infants (19.2% of admissions).

Aetiology

• Falls (22-43%) and assaults (30-50%) are the most common cause of a minor head injury, followed by road traffic accidents (25%). Road traffic accidents account for a far greater proportion of moderate-to-severe head injuries.³

• Alcohol may be involved in up to 65% of adult head injuries.

Head injury assessment¹

Head injury patients should be taken directly to a centre which can provide resuscitation and management of head injuries and trauma leading to multiple injuries.¹

Management should begin immediately with resuscitation. Following this:

In patients with normal or near-normal Glasgow coma scale (GCS) score and who are alert

• Haemodynamic status - pulse rate, blood pressure, fluid status.

• Neurological assessment - full history and examination; make notes of pupil size and reaction to light.

• Look for other possible injuries and any other relevant examination.

In patients with reduced GCS

• Resuscitate but make a quick assessment of GCS and pupils. The priority is to get the patient to hospital and CT scanned within the first hour after injury.¹

See also the article on Coma.

Assessment of the cervical spine

The range of movement in the neck when there is clinical suspicion of a cervical spine injury can only be assessed safely before imaging in people with a head injury if they have no high-risk factors (list of risk factors under indications for CT cervical spine below). Only do the assessment if they have at least 1 of these low-risk features:

• They were in a simple rear-end motor vehicle collision.

• They are comfortable in a sitting position.

• They have been ambulatory at any time since injury.

• There is no midline cervical spine tenderness.

• They present with delayed onset of neck pain.

See also the articles on Spinal Cord Injury and Whiplash and Cervical Spine Injury.

Pre-hospital treatment^{1 4}

Resuscitation

Basic and Advanced Trauma Life Support, and Basic and Advanced Paediatric Life Support as necessary. See also the articles on Trauma Assessment and Spinal Cord Injury.

Indications for referral to emergency ambulance services (999) for emergency transport to A&E

• Unconsciousness or lack of full consciousness (eg, problems keeping eyes open).

• Any focal neurological deficit since the injury.

• Any suspicion of a complex skull fracture or penetrating head injury.

• Any seizure since the injury.

• High-energy head injury.

• No other way of safely transporting the person to the hospital emergency department.

Indications for referral to hospital A&E department

• Any loss of consciousness because of the injury, from which the person has now recovered.

• Amnesia for events before or after the injury.

• Persistent headache since the injury.

• Any vomiting episodes since the injury.

• Any previous brain surgery.

• Any history of bleeding or clotting disorders.

• Current anticoagulant and antiplatelet (except aspirin monotherapy) treatment.

• Current drug or alcohol intoxication.

• Any safeguarding concerns (eg, possible non-accidental injury or a vulnerable person is affected).

• Irritability or altered behaviour (easily distracted, not themselves, no concentration, no interest in things around them), particularly in babies and children under 5.

• Continuing concern about the diagnosis.

Investigations¹

The current primary investigation of choice for detecting an acute clinically important traumatic brain injury is CT imaging of the head. Do not use plain X-rays of the skull to diagnose important traumatic brain injury before a discussion with a neuroscience unit. However, people under 16 presenting with suspected non-accidental injury may need a skeletal survey.

Criteria for doing a CT head scan

People 16 and over: do a CT head scan within 1 hour of any of these risk factors being identified:

• Glasgow coma scale (GCS) of 12 or less on initial assessment in the emergency department.

• GCS score of less than 15 at 2 hours after the injury on assessment in the emergency department.

• Suspected open or depressed skull fracture.

• Any sign of basal skull fracture (haemotympanum, 'panda' eyes, cerebrospinal fluid leakage from the ear or nose, Battle's sign).

• Post-traumatic seizure.

• Focal neurological deficit.

• More than 1 episode of vomiting.

For people 16 and over who have had some loss of consciousness or amnesia since the injury, do a CT head scan within 8 hours of the head injury, or within the hour in someone presenting more than 8 hours after the injury, if they have any of these risk factors:

• Age 65 or over.

• Any current bleeding or clotting disorders.

• Dangerous mechanism of injury (a pedestrian or cyclist struck by a motor vehicle, an occupant ejected from a motor vehicle or a fall from a height of more than 1 m or 5 stairs).

• More than 30 minutes' retrograde amnesia of events immediately before the head injury.

People under 16: do a CT head scan within 1 hour of any of these risk factors being identified:

• Suspicion of non-accidental injury.

• Post-traumatic seizure.

• On initial emergency department assessment, a GCS score of less than 14 or, for babies under 1 year, a GCS score (paediatric) of less than 15.

• At 2 hours after the injury, a GCS score of less than 15.

• Suspected open or depressed skull fracture, or tense fontanelle.

• Any sign of basal skull fracture (haemotympanum, 'panda' eyes, cerebrospinal fluid leakage from the ear or nose, Battle's sign).

• Focal neurological deficit.

• For babies under 1 year, a bruise, swelling or laceration of more than 5 cm on the head.

For people under 16 who have sustained a head injury and have more than 1 of these risk factors, do a CT head scan within 1 hour of the risk factors being identified:

• Loss of consciousness lasting more than 5 minutes (witnessed).

• Abnormal drowsiness.

• 3 or more discrete episodes of vomiting.

• Dangerous mechanism of injury (high-speed road traffic accident as a pedestrian, cyclist or vehicle occupant, fall from a height of more than 3 m, high-speed injury from a projectile or other object).

• Amnesia (anterograde or retrograde) lasting more than 5 minutes (unlikely to be possible to assess in children under 5).

• Any current bleeding or clotting disorder.

Observe people under 16 who have sustained a head injury but have only 1 of the risk factors for a minimum of 4 hours in hospital. If, during observation, any of the following risk factors are identified, do a CT head scan within 1 hour:

• GCS score of less than 15.

• Further vomiting.

• Further episode of abnormal drowsiness.

• If none of these risk factors occur during observation, use clinical judgement to determine whether a longer period of observation is needed.

People taking anticoagulant or antiplatelet medication: if no other indications for a CT head scan, but are on anticoagulant treatment (including vitamin K antagonists, direct-acting oral anticoagulants, heparin and low molecular weight heparins) or antiplatelet treatment (excluding aspirin monotherapy), consider doing a CT head scan:

• Within 8 hours of the injury (eg, if it is difficult to do a risk assessment or if the person might not return to the emergency department if they have signs of deterioration) or

• Within the hour if they present more than 8 hours after the injury.

Investigations for the cervical spine

For people 16 and over who have sustained a head injury (including people with delayed presentation), do a CT cervical spine scan within 1 hour of the risk factor being identified if any of these high-risk factors apply:

• GCS score is 12 or less on initial assessment.

• The person has been intubated.

• A definitive diagnosis of a cervical spine injury is urgently needed (eg, if cervical spine manipulation is needed during surgery or anaesthesia).

• There has been blunt polytrauma involving the head and chest, abdomen or pelvis in someone who is alert and stable.

• There is clinical suspicion of a cervical spine injury and any of these factors:

• • Age 65 or over.

  • A dangerous mechanism of injury (ie a fall from a height of more than 1 m or 5 stairs, an axial load to the head such as from diving, a high-speed motor vehicle collision, a rollover motor accident, ejection from a motor vehicle, an accident involving motorised recreational vehicles or a bicycle collision).

  • Focal peripheral neurological deficit.

  • Paraesthesia in the upper or lower limbs.

For people 16 and over who have sustained a head injury, and have neck pain or tenderness but no high-risk indications for a CT cervical spine scan, do a CT cervical spine scan within 1 hour for any of these risk factors:

• It is not thought to be safe to assess the range of movement in the neck.

• Safe assessment of range of neck movement shows that the person cannot actively rotate their neck 45 degrees to the left and right.

• The person has a condition predisposing them to a higher risk of injury to the cervical spine (eg, axial spondyloarthritis).

Criteria for doing a CT cervical spine scan in people under 16 (do the scan within 1 hour of the risk factor being identified):

• GCS score is 12 or less on initial assessment.

• Person has been intubated.

• There are focal peripheral neurological signs.

• There is paraesthesia in the upper or lower limbs.

• A definitive diagnosis of a cervical spine injury is needed urgently (eg, if manipulation of the cervical spine is needed during surgery or anaesthesia).

• The person is having other body areas scanned for head injury or multisystem trauma, and there is clinical suspicion of a cervical spine injury.

• There is strong clinical suspicion of injury despite normal X-rays.

• Plain X-rays are technically difficult or inadequate.

• Plain X-rays identify a significant bony injury.

For people under 16 who have sustained a head injury, and have neck pain or tenderness but no indications for a CT cervical spine scan, do 3-view cervical spine X-rays before assessing range of movement in the neck if any of these risk factors are identified (the X-rays should be done within 1 hour of the risk factor being identified):

• There was a dangerous mechanism of injury (ie a fall from a height of more than 1 m or 5 stairs, an axial load to the head such as from diving, a high-speed

• motor vehicle collision, a rollover motor accident, ejection from a motor vehicle, an accident involving motorised recreational vehicles or a bicycle collision).

• Safe assessment of range of movement in the neck is not possible.

• The person has a condition that predisposes them to a higher risk of injury to the cervical spine (eg, collagen vascular disease, osteogenesis imperfecta, axial spondyloarthritis).

If range of neck movement can be assessed safely in a person under 16 who has sustained a head injury, and has neck pain or tenderness but no indications for a CT cervical spine scan, do 3-view cervical spine X-rays if they cannot actively rotate their neck 45 degrees to the left and right. When the person is unable to understand commands or open their mouth, a peg view may be omitted. The X-rays should be done within 1 hour of this risk factor being identified.

Admission¹

The following patients meet the criteria for admission to hospital following a head injury:

• New, clinically important abnormalities on imaging (an isolated simple linear non-displaced skull fracture is unlikely to be a clinically important abnormality unless they are taking anticoagulant or antiplatelet medication).

• After imaging, a GCS score that has not returned to 15 or their pre-injury baseline, regardless of the imaging results.

• When there are indications for CT scanning but this cannot be done within the appropriate time period, either because CT is not available or because the person is not sufficiently cooperative to allow scanning.

• Continuing worrying symptoms (eg, persistent vomiting, severe headaches or seizures) of concern to the clinician.

• Other sources of concern to the clinician (eg, drug or alcohol intoxication, other injuries, shock, suspected non-accidental injury, meningism, cerebrospinal fluid leak, or suspicion of ongoing post-traumatic amnesia).

Patients not requiring admission

All patients and their carers should be given clear advice, both in verbal and written form. This should include information on:⁵

• Details of the injury - including the nature and severity.

• Warning signs that warrant further immediate medical assessment:
  

  • Increasing drowsiness.

  • Worsening headache.

  • Confusion or strange behaviour.

  • Two or more bouts of vomiting.

  • Focal neurological problem - eg, limb weakness.

  • Dizziness, loss of balance, or convulsions.

  • Any visual problems such as blurring of vision, or double vision.

  • Blood, or clear fluid, leaking from the nose or ear.

  • Unusual breathing patterns.

• That a responsible adult will stay with the patient until the first 24 hours following the injury.

• How long recovery is likely to take and what this will involve - including when they can go back to work and undertake everyday activities (eg, school and sports).

• Potential complications.

• Whom to contact if further help is needed.

• Available support organisations.

Indications for neurosurgical opinion¹

• New, surgically significant abnormalities on imaging.

• Persisting coma (GCS ≤8) after initial resuscitation.

• Unexplained confusion which persists for more than four hours.

• Deterioration in GCS score after admission (greater attention should be paid to motor response deterioration).

• Progressive focal neurological signs.

• A seizure without full recovery.

• Depressed skull fracture.

• Definite or suspected penetrating injury.

• A CSF leak.

Head injury treatment and management

The following statements relate to the routine management of patients following a head injury. See the separate Raised Intracranial Pressure article.

• Early nutritional support may be associated with a trend towards better outcomes in terms of survival and disability.⁶

• There is no reduction in mortality with methylprednisolone in the two weeks after head injury.^{7 8} One large study showed an increase in mortality with steroids suggesting that steroids should no longer be used routinely in people with traumatic head injury.⁹

• There is no consistent evidence that hypothermia is beneficial in the treatment of head injury.^{10 11 12}

• High-dose mannitol is beneficial in the pre-operative management of patients with acute intracranial haematomas. There are insufficient data on the effectiveness of pre-hospital administration of mannitol for acute traumatic brain injury.¹³

• Prophylactic anti-epileptics are effective in reducing early seizures, but there is no evidence that treatment with prophylactic anti-epileptics reduces the occurrence of late seizures.¹⁴

Discharge and follow up¹

People admitted after a head injury may be discharged after resolution of all significant symptoms and signs, provided they have suitable supervision arrangements at home, in custody or in continued care.

If CT is not indicated based on history and examination and there is no suspicion of clinically important traumatic brain injury, discharge the person from hospital if there are:

• No other factors that would warrant a hospital admission (eg, drug or alcohol intoxication, other injuries, shock, suspected non-accidental injury.

• Appropriate support structures for safe discharge to the community and for subsequent care (eg, competent supervision at home).

• If imaging of the head is normal and the risk of clinically important traumatic brain injury is low, transfer the person to the community if:

• The GCS score has returned to 15 or the pre-injury baseline GCS score.

• There are no other factors that would warrant a hospital admission (eg, drug or alcohol intoxication, other injuries, shock, suspected non-accidental injury, meningism, or cerebrospinal fluid leak).

• There are appropriate support structures for safe transfer to the community and for subsequent care (eg, competent supervision at home).

• After normal imaging of the cervical spine, risk of injury to the cervical spine is low enough to warrant transfer to the community if:

• GCS score is 15.

• Clinical examination is normal.

• There are no other factors that would warrant a hospital admission present (eg, drug or alcohol intoxication, other injuries, shock, suspected non-accidental injury, meningism, or cerebrospinal fluid leak).

• There are appropriate support structures for safe transfer to the community and for subsequent care (eg, competent supervision at home).

Do not discharge people presenting with a head injury until their GCS score is 15 or, in preverbal and non-verbal children, consciousness is normal as assessed by the paediatric version of the GCS. In people with pre-injury cognitive impairment, their GCS score should be back to that documented before the injury.

Only transfer people with any degree of head injury to their home if there is somebody suitable at home to supervise them. Discharge people with no carer at home only if suitable supervision arrangements have been organised, or when the risk of late complications is thought to be negligible.

Ensure that people with pre-injury cognitive impairment (eg, dementia or a learning disability) and people returning to a custodial setting are supervised and monitored. Also, make sure that arrangements are in place should there be any signs of deterioration.

Give verbal and printed discharge advice to people with any degree of head injury who are discharged from an emergency department or observation ward. This should also be provided to the person responsible for their care after discharge. This may include their families, carers, social workers or custodial staff.

Follow up

Refer people with a head injury to investigate its causes and manage contributing factors, if appropriate, eg, referral for a falls assessment or to safeguarding services.

Consider referring people who have persisting problems to a clinician trained in assessing and managing the consequences of traumatic brain injury (eg, neurologist, neuropsychologist, clinical psychologist, neurosurgeon or endocrinologist, or a multidisciplinary neurorehabilitation team).

Complications²

• Neurological deficits, eg, gait disturbance, reduced mobility, muscle weakness, spasticity, contractures, and communication and swallowing problems (eg, dysarthria, dysphasia, and other difficulties in the use of language).

• Intracranial lesions, eg, extradural or subdural haematoma, subarachnoid haemorrhage, cerebral contusion, or intracerebral haematoma. The risk of intracranial haemorrhage is increased in people taking anticoagulant medication.

• Skull fracture.

• Post-traumatic seizures.

• Hypopituitarism (particularly following moderate or severe brain injury):

  • Hypopituitarism is estimated to occur in 33–50% of all people following traumatic brain injury, and may be caused by haemorrhage, raised intracranial pressure, oedema, skull fracture, or direct insult to the pituitary gland.

  • Symptoms are often non-specific and overlap with post-concussion symptoms.

  • Rare life-threatening complications include sodium dysregulation and adrenal crisis.

  • Mild traumatic brain injury (concussion) — transient disturbance in the function of the brain caused by head injury:

    • Commonly reported symptoms include headache, dizziness, difficulty concentrating, and confusion.

    • Continuing to play a contact sport with concussion increases the risk of further head or non-head injury, worsened severity, and delayed recovery.

  • Depression and anxiety. Mood disorders are a common complication of head injury.

  • Post-traumatic stress disorder (PTSD). PTSD can occur after severe head injury even if there is no recollection after the traumatic event (extended post-traumatic amnesia).

  • Cognitive impairment. Cognitive impairment may include problems with memory, attention and concentration, planning, problem solving, language, and perception.

  • Challenging behaviour. Challenging behaviour may include inappropriate vocalisation, disinhibited or sexualised behaviour.

Prognosis^{1 2}

• In the UK, head injury is the commonest cause of death and disability in people aged 1–40 years.

• About 0.2% of all people attending emergency departments with a head injury die as a result. The majority of deaths are in people who present with a moderately or severely impaired consciousness level.

A UK prospective survey of children aged less than 15 years who were admitted to hospital with head injury reported a mortality rate of 0.4% (predominantly as a result of motor vehicle accident or abusive head trauma).

A study looked at long-term health outcomes after exposure to repeated concussion among elite level rugby union players:¹⁵

• Where there were signs of long-term effects overall, they were mild.

• General health and mental health of the retired international players were not poorer than controls, and on cognitive tests the retired international players performed in the normal range.

• Where differences were found, they were not associated with a higher number of repeat concussions.

• There were limitations to this study, being retrospective with self-reported recall of concussion events and a modest sample size, so further work is needed with a study of a larger cohort of retired athletes.

Head injury prevention

• Preventative measures include safer roads, barriers to prevent falls, and gun control legislation.

• In addition, bicycle and motorcycle helmets, seatbelts, airbags, and soft surfaces on playgrounds, are effective.¹⁶

• 25-30% of head injuries in infants are the result of an abuse - healthcare professionals need to be trained in safeguarding and to raise concerns without delay.¹