Extradural haematoma

Question 1

What is the definition of an extra-dural haematoma?

Answer 1

collection of blood between the outer dura mater and the inner surface of the skull

Question 2

What is almost always the cause of an extradural haematoma?

Answer 2

almost always trauma, most typically ‘low impact’ trauma e.g. blow to the head or a fall, or sport or RTA

Question 3

What is the commonest source of an extradural haematoma?

Answer 3

middle meningeal artery - collection often at temporal region since skull at pterion overlies this artery

Question 4

What is the classic presentation of extradural haematoma?

Answer 4

typically a brief loss of consciousness followed by regaining of normal consciousness level (the lucid interval), with subsequent deterioration of consciousness and headache

Question 5

Why is the lucid interval eventually lost in extradural haematoma?

Answer 5

due to the expanding haematoma and brain herniation

as the haematoma expands, the uncus of the temporal lobe herniates around the tentorium cerebelli

Question 6

What clinical sign does the uncal herniation in extradural haematoma cause?

Answer 6

fixed dilated pupil due to the compression of the parasympathetic fibres of the third cranial nerve - as haematoma expands, uncus of the temporal lobe herniates around the tentorium cerebelli

Question 7

What are the imaging findings on CT in extradural haematoma?

Answer 7

lentiform (or lemon/ biconvex) shaped, heterogenous, hyperdense extra-axial collection

Question 8

What proportion of cases of EDH are unilateral?

Answer 8

>95%

Question 9

Within which region do most extradural haemorrhages occur?

Answer 9

>95% of cases are supratentorial, of which 60% are in the temporo-parietal region

Question 10

What must you check for on a CT scan of EDH and why?

Answer 10

secondary features of mass effect on CT scan: e.g. midline shift, subfalcine/uncal herniation

as this may require urgent neurosurgical intervention

Question 11

In addition to the shape of the haematoma on CT in EDH, what else defines this type of haematoma?

Answer 11

limited by the suture lines of the skull

Question 12

What is the approach to management of patients with EDG and no neurological deficit?

Answer 12

cautious clinical and radiological observation

Question 13

What is the definitive treatment for EDH when indicated?

Answer 13

craniotomy and evacuation of the haematoma

Question 14

Which age group is typically affected by extradural haematoma?

Answer 14

young patients