Head injury

Question 1

What are the commonest causes of head injuries in the UK?

Answer 1

road traffic accidents

alcohol-related incidents - including assaults

Question 2

Following the primary insult to the head - what secondary insults may follow?

Answer 2

Hypotension

Hypoxia

Infection

Haematoma

Question 3

Describe the initial assessment process for head injuries

Answer 3

Conscious level assessed using Glasgow coma scale (GCS)

GCS score is out of 15

Question 4

Describe how GCS scores reflect severity of head injuries

Answer 4

13-15 (high) - Mild injury

9-12 - Moderate injury

3-8 - Sever injury

Question 5

What significant complications can develop as a result of head injuries?

Answer 5

1.Permanent physical disability

2. Post traumatic epilepsy
3. Intracranial infection
4. Psychiatric illness
5. Chronic subdural haemorrhage
6. ‘Punch-drunk’ dementia
7. Fatal outcome (uncommon)

Question 6

What types of injuries can affect the scalp?

Answer 6

Similar to those affecting the skin:

• abrasions, bruises, lacerations, incisions (and burns/scalds)

Often obscured by hair

Question 7

The skull can be split into 2 elements

What are these?

Answer 7

Skull vault (upper part):

• includes frontal bone, squamous temporal bones and occipital bone
• These are all separated by sutures

Skull base (what the brain rests on):

• divided into the anterior, middle and posterior cranial fossae

Question 8

What are the main types of skull fractures?

Answer 8

Linear skull fracture (+ “hinge” fracture)

Depressed skull fracture

Comminuted (mosaic) - fragmented skull

“Ring” fracture

“Contre-coup” fracture

Question 9

What is a linear fracture?

Answer 9

Break in a cranial bone resembling a thin line, without splintering, depression, or distortion of bone

Commonly temporo-parietal from blow or fall onto side or top of the head

May continue to skull base to make a “hinge” fracture

Question 10

What is a depression fracture?

Answer 10

Break in a cranial bone (or “crushed” portion of skull) with depression of the bone in toward the brain

Fragments may damage the meninges, blood vessels and brain

Rarely arises due to falls etc

Question 11

What conditions may arise post-depression fracture?

Answer 11

Meningitis

Post-traumatic Epilepsy

Question 12

What is a ring fracture?

Answer 12

fracture line encircling the foramen magnum caused by a fall from height - even if patient lands on feet

caused by skull base and cervical spine being forced together

Question 13

What is a Contre-coup fracture?

Answer 13

fracturing of the orbital plates (anterior fossa) caused by a fall onto the back of the head

Question 14

Identify the types of fracture shown

Answer 14

Question 15

What is an intracranial haemorrhage and what is their association with fractures?

Answer 15

Collective term for any type of Bleeding/accumulation of blood within the skull (cranium)

Intracranial haemorrhages often happen as a result of fractures that have damaged nearby vessels

Question 16

What are the types of intracranial haemorrhage?

Answer 16

Extradural haemorrhage:

• Between dura and skull

Subdural haemorrhage:

• Beneath dura and above arachnoid

Subarachnoid haemorrhage:

• Beneath arachnoid layer and above the pia (effectively the brain)

Also included are intracerebral haemorrhage & cerebellar haemorrhage but we dont care about those right now

Question 17

Intracranial haemorrhages caused increased Intracranial pressure - leading to compression of the brain and the symptoms we know and love

Without intervention - how would this progress?

Answer 17

Ultimately - death will occur by compression of the brainstem

This compression is due to herniation of the cerebellar tonsils into the Foramen Magnum

Question 18

What causes Extradural haemorrhage?

Answer 18

Skull fractures with associated arterial damage

• Rarely due to veins

Classically:

Middle meningeal artery damage - from linear fracture to inner aspect of Squamous^arrowed temporal bone

Question 19

What causes Subdural haemorrhages?

Answer 19

Frequently occurs without skull fracture

Usually caused by bleeding from bridging veins which pass from the surface of the brain to drain into the large venous channels within the dura

Any motion which causes rotational or “shearing” forces can cause the veins to be stretch and torn

Question 20

What causes Subarachnoid haemorrhages?

Answer 20

Most commonly - Rupture of a cerebral artery (“berry”) aneurysm

• Natural disease (non-traumatic)

AVM - arteriovenous malformation

Trauma:

• SAH frequently seen with Cerebral contusions (bruises to the brain) post-trauma
• “Traumatic Basal SAH” - specific type of SAH caused by

Question 21

How would Extradural haemorrhage and subdural haemorrhage present?

Answer 21

*Post-trauma to head ± brief period of unconsciousness*

Often - patients with EDH or SDH will have a ‘lucid period’ without neurological symptoms

Followed by rapid Deterioration

​

Question 22

How does subarachnoid haemorrhage present?

Answer 22

Sudden, rapid onset of:

• Very severe headache
• Nausea & vomiting
• Syncope/collapse

May have:

• Some aspects of meningism
  
  • Neck stiffness
  • Kernig’s sign - indicator or Mening. & SAH
• Papilloedema
• Photophobia etc

Question 23

What is the clinical significance of Chronic Sub-dural haemorrhage?

Answer 23

This sometimes happens to the elderly

Can cause chronic confusion (and may be mistaken for dementia)

Question 24

What is cerebral oedema?

Answer 24

Type of intrinsic brain injury characterized by massive brain swelling, increase in ICP and ‘coning’

Common and rapid result of brian injury - especially in children

Question 25

What is the difference between ‘coup’ contusions and ‘contre-coup’ contusions?

Answer 25

Coup contusions:

• occur when head struck by a heavy blow
• contusion is found directly under the site of impact

Contre-coup contusions:

• caused by a moving head striking a fixed object or unyielding surface
• Contusions found diametrically opposite the site of head impact

Question 26

What is meant by a ‘diffuse axonal injury’?

Answer 26

lol who knows