Cranial Trauma

Question 1

Classify skull fractures.

Answer 1

linear
depressed
compound

Question 2

Discuss contusions.

Answer 2

Impact of an object with the head leading to:
* Collision of brain with skull at site of impact (coup)
* Opposite side (contrecoup)
Crests of gyri most susceptible (cortex along sulci less vulnerable)
Rapid tissue displacement  disruption of vascular channels 
subsequent haemorrhage, tissue injury and oedema

frontal more susceptible
penetration leads to tissue tearing, vascular disruption and haemorrhage
Acute: Hemorrhagic necrosis and oedema

Question 3

Discuss the pathology of a subdural haemorhage.

Answer 3

• Initially the subdural haematoma is a flat blood
  clot not attached to the dura
• Fibroblast ingrowth causes organization
• After 10-20 days – outer membrane is formed
• Then inner membrane forms
• Subdural becomes entirely encapsulated
• Further organization leads to formation a sac with
  a fibrous wall (chronic subdural haematoma)

Question 4

Discuss the pathophysiology of diffuse axonal injury.

Answer 4

• Axons are stretched  changes in axonal cytoskeleton
• Mitochondria accumulate proximally (spheroids)
• Mitochondrial dysfunction
• Leads to axonal rupture
• Neuroinflammation
• Wallerian degeneration
• Multifaceted process
• Evolution over time
• Most severe damage is along midline structures

Question 5

What are the pathologies seen in a diffuse axonal injury?

Answer 5

• Petechial haemorrhages in:
• Corpus callosum
• Dorsolateral brainstem
• Other areas
• Due to tearing of blood vessels
• Microscopically axonal swellings (spheroids) are seen
• BAPP immunohistochemistry