APATH - HAEMORRHAGE

Question 1

[No case] State the predisposing factor present in this patient that increases his risk of developing a subdural haematoma in response to trauma. Explain the mechanism (3)

Answer 1

atrophic brain because elderly

Question 2

Contrast the macroscopic differences between an acute subdural haematoma and an extradural haematoma. Indicate the type of bleeding vessel in each (4)

Answer 2

• Fracture in extradural
• Typically covers a small surface area of brain with deep extension in extradural
• Artery in extradural, vein in subdural

Question 3

Describe the pathogenesis of an extradural haematoma (3)

Answer 3

Acute head injury – temporal or parietal fracture, laceration of middle meningeal artery – accumulation of blood extradurally because dura has been stripped from the bone

Question 4

At surgery, a chronic subdural was identified. It was determined that Mr Jantjies’ episode of trauma at the fishing harbour was co-incidental and that the causative injury had been sustained previously.

Explain why a chronic subdural may present clinically a long time after the haemorrhage has ceased (2)

Answer 4

Breakdown of blood  increased osmolality  fluid drawn into subdural region  increased volume

Question 5

Given the limited clinical history above, outline what ocular signs might be present in:

• Hypertension (1)
• Raised intracranial pressure (3)

Answer 5

Retina: hypertensive retinopathy

Pupils (pupillary dilation), Optic disc (papilloedema), III nerve weakness

Question 6

Explain why aspirin would be contra-indicated in a case of acute subdural haemorrhage (2)

Answer 6

Aspirin inhibits the enzyme cyclo-oxygenase which in turn decreases the amounts of endoperoxides PGG2 and PGH2. These are the substrates for the formation of TXA2 which cause platelet aggregation and vessel vasoconstriction.