Head injury

Question 1

Is blunt trauma or penetrating trauma to the head more likely?

Answer 1

Blunt trauma

Question 2

What focal damage can you expect following blunt trauma to the head?

Answer 2

scalp contusions and lacerations
skull fracture - needs considerable force (flat surfaces cause linear fracture whereas angled objects cause a depression in the skull)
haemorrhage or infection

Question 3

In an extradural haemorrhage, which artery is usually damaged and why? How is an extradural haemorrhage usually caused?

Answer 3

Associated with skull fracture and the middle meningeal artery which transverses the frontal/parietal plate (weaker site) tears and causes a slow bleeding which dissects the dura from the skull.

Question 4

Which haemorrhage typically has a lucid interval?

Answer 4

Extradural haemorrhage

Question 5

Which haemorrhage occurs due to tears in bridging veins which cross the subdural space? Do they occur slowly or quickly?

Answer 5

Subdural haematoma - occur slowly and lead to raised ICP

Question 6

Which haemorrhage is usually caused by either berry aneurysm rupture or base of skull fracture?

Answer 6

Subarachnoid haemorrhage

Question 7

What is the cycle caused by hypoxia Ischaemia?

Answer 7

Hypoxia ischaemia causes infarction and hypoxic ischaemic damage due to inadequate oxygenated blood into brain. HI causes a cycle as HI causes oedema and swelling which causes further damage which leads to further oedema and swelling etc.

Question 8

Hypoxia Ischaemia in likely in patients who have had what?

Answer 8

• Clinically evident hypoxia
• Hypotension with systolic BP <80 for more than 15m (loss of blood)
• Raised ICP

Question 9

Chronic traumatic encephalopathy is a long term effect of brain injury. How is it commonly caused?
What symptoms do we see early and late?

Answer 9

Repetitive mild traumatic brain injury
Early: irritability, impulsivity, aggression, depression and memory loss
Later: dementia, gait and speech problems, parkinsonism.