Extradural haemorrhage

Question 1

What is an extradural haematoma?

Answer 1

Collection of blood that is between the skull and the dura.

Also called “epidural” haemorrhage

Question 2

What type of injury causes extradural haematomas?

Answer 2

Low impact trauma e.g. fall or blow to the head

Question 3

Where do extradural haematomas usually occur?

Answer 3

Temporal region, since skull is think here at the pterion which overlies the middle meningeal artery (MMA) and is vulnerable to injury.

Question 4

What bones join at the pterion?

Answer 4

1. Frontal
2. Parietal
3. Temporal
4. Sphenoid

Question 5

What are the clinical features of extradural haematoma?

Answer 5

Initial loss of consciousness
Briefly regain consciousness - ‘lucid interval’
Lose consciousness again - haematoma expands
Hx of low impact head injury
Headache, focal signs (ipsilateral CNIII), Cushing reflex
Otorrhea/rinorrhea

Question 6

What are the complications of expanding epidural haematomas?

Answer 6

Brain herniation
* Uncus of temporal lobe herniates around tentorium cerebelli –> fixed and dilated pupil due to compression of parasympathetic fibres of CNIII
* Brainstem compression causing heart and respiratory arrest
Paralysis and sensory loss
Seizures
Raised ICP

Question 7

Describe the appearance of an extradural haematoma on CT.

Answer 7

• Biconvex (or lentiform)
• Hyperdense collection
• Around surface of the brailn
• Limited by suture lines of the skull

“Swirl sign” = bleeding into blood clot

Question 8

What is the management of extradural haematomas?

Answer 8

If no neurological deficit –> careful observation, esp if <30ml + <5mm midline shift
Medications to reduce ICP - mannitol, osmotic diuretics
Definitive treatment –>
* craniotomy - evacuation of haematoma
* embolisation/ligation of damaged vessels
* trephination (burr hole) - in ED
* laminectomy - for spinal epidural haematomas

Question 9

What are the types of epidural haematomas?

Answer 9

Frontal –> anterior ethmoidal artery
Temporoparietal –> MMA
Occipital –> transverse, sigmoid sinus
Vertex –> superior saggital sinus

Spinal –> venous plexus of lumbar, thoracic regions

Question 10

What are the causes of epidural haematoma?

Answer 10

• Neurosurgical procedure complication
• Trauma
• Blood vessel malformations
• Lumbar puncture

Question 11

What are the risk factors for epidural haematoma?

Answer 11

• Male
• 2-60yrs
• Pregnancy - can cause spontaneous spinal haematoma (very rare)
• SLE - vasculitis
• Coagulopathy, bleeding diathesis, SCA

Question 12

Which type of MRI would show the bleed acutely vs long term?

Answer 12

MRI:
T2-W1 = acutely shows hypointense blood clot
T1-W1 = months later shows methemoglobin –> haemosiderin; hypointense mass.

Question 13

What medications may be used in extradural haematoma?

Answer 13

• Mannitol
• Osmotic diureics
• Anticoagulation reversal