Head injury

Question 1

Head injury is classified based on the patient’s Glasgow Coma Scale (GCS):

Answer 1

Minimal = 15, with no loss of conciousness

Mild = 13-15

Moderate = 9-12

Severe = 3-8

Question 2

How would you perform an initial assessment of a patient presenting to A&E with evidence of a head injury?

Answer 2

At the start of the assessment consider whether the cervial spine requires immobilisation via a semi-rigid collar, blocks, and tape.

A to E algorithm

Question 3

Assessment of head injury

Airway

Answer 3

If the GCS is 8 or less call the on call anaesthetic team immediately to assist with airway management.

If a suspected cervical spine injury, a jaw thrust is typically the most appropriate.

Question 4

Assessment of head injury B

Answer 4

Ensure adequate ventilation and oxygenation

Question 5

Assessment of head injury C

Answer 5

Ensure adequate tissue perfusion. Ensure a good circulating volume is maintained from resuscitation with appropriate fluids.

Question 6

Assessment of head injury D

Answer 6

An accurate Glasgow Coma Scale must be reported on admission. This will typically be repeated every 30-60 minutes.

Assess patient’s pupils, both size and response to light.

Assess for focal neurological deficit with a full neurological examination.

Measure blood glucose and avoid hypoglycaemia.

Question 7

How would you score a Glasgow Coma Scale?

Answer 7

Question 8

Head injury assessment E

Answer 8

Examine carefully for lacerations, evidence of facial fractures, or depressed skull fractures.

Question 9

What evidence may you see of a basal skull fracture?

Answer 9

• Bruising around the eyes (raccoon eyes)
• Bruising behind the ears (Battle’s sign)
• Clear discharge from the nose or ear
• Blood building from middle ear (haemotympanum)

Question 10

Red flags in head injury

Answer 10

• Impaired consciousness level
• Fixed and dilated pupils
• Signs of basal skull fracture
• Focal neurological deficit or visual disturbance
• Seizures or amnesia
• Significant headache or nausea and vomiting

Question 11

Imaging following head injury

Answer 11

CT head

(not all head injuries require imaging and the decision to perform a CT scan is usually made immediately after the initial ABCDE assessment, following set criteria)

Question 12

What is a subdural haematoma?

Answer 12

A collection of blood that forms in the subdural space. It most commonly occurs secondary to tearing of the bridging veins that cross from the cortex to the rural venous sinuses.

This subsequently leads to accumulation of blood between the dura and arachnoid and results in a gradual rise in intracranial pressure. This leads to herniation and brain stem death if left untreated.

Question 13

How can subdural haematoma be classified?

Answer 13

Acute (<3 days after injury), subacute (3-21 days), or chronic SDH (>21 days)

Question 14

Risk factors for subdural haematoma

Answer 14

• Increasing age (brain atrophy causes stretching of bridging veins = more vulnerable)
• Alcohol excess
• Epileptics (prone to falls and head injury)
• Clotting disorders or taking anti-coagulants

Question 15

Clinical features of subdural haematoma

Answer 15

• Altered level of conciousness
• Headaches
• Focal neurology
• Features of raised intracranial pressure (such as blurred vision, worsening headache)
• Seizure activity

Question 16

Differential diagnosis for subdural haematoma

Answer 16

• Acute subdural haematoma
  
  • extramural haematoma, subarachnoid haemorrhage, or intracerebral haemorrhage or infarction
• Chronic subdural haematoma
  
  • space occupying lesions, meningitis or encephalitis, or dementia

Question 17

Investigations for subdural haematoma

Answer 17

• Patients should have initial routine bloods, including FBC, U&Es, LFTs, CRP, clotting and a group and save
• Non-contrast head CT - crescent- shaped collection of blood over one hemisphere, with or without associated midline shift

Question 18

Management of subdural haematoma

1) Initial management
2) Which patients will be managed conservatively?
3) Surgical intervention for acute subdural haematoma?

Answer 18

1. Systemic A to E assessment, anticoagulation should be reversed appropriately, patients are often started on anti-epileptic medication for 1 week after presentation of a SDH
2. Small acute SDH that does not cause significant midline shift
3. Evacuation of haematoma via burr hole craniostomy or a hemicraniectomy if there is significant cerebral swelling

Question 19

What is an extradural haematoma?

Answer 19

A pooling of blood between the dura mater and the skull.

Question 20

Which group is most commonly affected by an extra-dural haematoma?

Answer 20

Young men (likely associate with high risk behaviours, including crime/violence and participation in contact sports)

Question 21

Pathophysiology of extra-dural haematoma

Answer 21

Extradural haematomas typically occur following blunt force head trauma resulting in a linear skill fracture, with no or minimal displacement.

The middle meningeal artery is the most common source of bleeding, occurring due to a fractured pterion.

Question 22

Clinical features of extradural haematoma

Answer 22

Classic picture of an initial loss of consciousness at the time of injury, followed by a lucid period, before further deterioration.

Symptoms may include headache, nausea and vomiting, or progressive drowsiness.

Question 23

What would a head CT of an extradural haematoma show?

Answer 23

A hyperdense biconvex lens-shaped lesion, potentially with an associated skull fracture.

Question 24

When should an extradural haematoma be managed conservatively?

Answer 24

<30cm² with low thickness, minimal midline shift, GCS >8 without any focal neurological deficits

Question 25

Surgical management of extradural haematoma

Answer 25

Craniotomy or Burr holes

Any bleeding sources identified should be controlled through ligation or cauterisation, if necessary

Question 26

Cause of diffuse axonal injury

Answer 26

Sudden acceleration or deceleration against the solid skull causes shearing of the axonal tracts of the white matter.

Road traffic accidents, assaults and falls are common aetiologies.

Question 27

Clinical features of diffuse axonal injury

Answer 27

Loss of conciousness at the time of injury with a prolonged post-traumatic coma.

(Often the diagnosis is only suspected when patients do not make a neurological recovery.)

Question 28

Imaging in diffuse axonal injury

Answer 28

MRI imaging serves as the best modality for DAI detection.

Even severe cases of DAI can have relatively normal CT imaging.

Question 29

What pathology does the following head CT show?

Answer 29

Subdural haematoma

Question 30

What pathology does the following head CT show?

Answer 30

Extra-dural haematoma