Before starting on this section, it is vital that you can answer the following questions:
- What are the three purposes of the meninges?
- What are the three layers of the meninges?
- Where is the extradural space?
Not quite sure what the answers are? Do not worry, click on the button below!
After completing the “Extradural Haemorrhage” section, you will be able:
- To apply knowledge of the pterion to explain the pathophysiology
- To explain the clinical presentation and immediate management
- To apply knowledge to evaluate the diagnosis
- To discuss the management
- To validate knowledge by completing the quiz
Extradural Haemorrhage = Extradural Haematoma
Sport Risk Factors
Boxing, Mixed Martial Arts (MMA!! Remember this!), Rugby and other contact sports involving trauma to the head.
Conor McGregor, the famous MMA fighter from the UFC, has been brought to A&E following a fight in which he got struck in the side of the head. At the time, Mr McGregor became instantly unconscious before regaining consciousness over the last 3 hours. Subsequently, he became increasing confused and his condition worsened.
1. Fracture of the skull due to head trauma:
- Classically, trauma to the pterion causing a fracture to the parietal or temporal bone
2. Rupture of the Middle Meningeal Artery (MMA)
3. Arterial blood rapidly accumulates in the extradural space – the area between the bone (cranium) and the dura
The pterion is the structurally weak region on the lateral aspect of the skull where four bones join together:
- Frontal bone
- Parietal bone
- Sphenoid bone (greater wing)
- Temporal bone (squamous part)
The middle meningeal artery (MMA) lies underneath the pterion. Fracture to the pterion can, therefore, disrupt the MMA leading to an extradural haemorrhage.
1. Head injury/trauma with brief loss of consciousness
2. Lucid interval (up to 3 days):
- Improvement in consciousness known as the lucid interval.
3. Deteriorating consciousness:
- Falling Glasgow Coma Score due to raised intracranial pressure (ICP). * Imagine the skull as a rigid closed box that cannot expand. Blood accumulating in the extradural space increases the pressure within the box *
- if unresolved, this can lead to a coma –> death due to respiratory arrest
1. A-E assessment. Immediately take to A&E/call for an ambulance.
TIP: * Mnemonic alert * A-E assessment
- A: Airway
- B: Breathing
- C: Circulation
- D: Disability
- E: Exposure
1. Through the clinical presentation – history of trauma
2. CT Head under 1 hour!
* HINT: white = acute blood on CT scans *
- On the CT scan of an extradural haemorrhage, the haematoma (collection of blood) has a biconcave/egg-shaped appearance.
- The haematoma does not cross the suture lines (tough dural attachments) within the extradural space. Hence, the appearance of an egg-shaped haematoma between distinct regions.
* TOP TIP: extradural haemorrhage = EGG – stradural haematoma *
- Stabilise and transfer urgently to neurosurgical unit
- Clot evacuation +/- ligation of the bleeding vessel
- EGGcellent (see what I did there!) if diagnosis and management are performed early.
- Poor if coma, pupil abnormalities or decerebrate rigidity pre-operatively.
AnatomyZone. (2016). Pterion. [online] Available at: http://anatomyzone.com/anatomy-feed/pterion/ [Accessed 1 March 2017].
Kumar P, & Clark M. (2016). Kumar & Clark’s Clinical Medicine. 9th Ed. Edinburgh: Elsevier.
Longmore M, Wilkinson I, Baldwin A, Wallin E. (2014). Oxford Handbook of Clinical Medicine. 9th ed. Oxford: Oxford University Press.
National Institute for Health and Care Excellence. (2016). Head Injury Overview. London: National Institute for Health and Care Excellence.