Pathology of head injury

Question 1

What percentage of head injuries result in serious permanent neurological deficit?

Answer 1

0.1%

Question 2

Name some primary insults in head injury.

Answer 2

Focal brain tumour

Diffuse brain tumour

Question 3

Name some secondary insults in head injury.

Answer 3

Hypotension
Hypoxia
Infection
Haematoma

Question 4

What GCS score would indicate a mild head injury?

Answer 4

13-15

Question 5

What GCS score would indicate a moderate head injury?

Answer 5

9-12

Question 6

What GCS score would indicate a severe head injury?

Answer 6

3-8

Question 7

What is “punch -drunk” dementia?

Answer 7

Dementia originating from repeated concussion or other head trauma

Question 8

Why is the scalp such a common site for lacerations?

Answer 8

It is closely applied to the skull

Question 9

What is a linear skull fracture?

Answer 9

Runs from top/side towards base

Commonly results from falls onto side/head

Question 10

What is a depressed skull fracture?

Answer 10

Focal impact which may push fragments inside

Often damages meninges, blood vessels, brain

Question 11

What is a comminuted fracture?

Answer 11

Fragmented

Question 12

What is a ring fracture?

Answer 12

Fracture encircles the base of the skull
Usually results from falls from height
Spine and skull base forced together

Question 13

What is a contre-coup fracture?

Answer 13

Fracture of orbital plates

Usually from falling backwards and hitting the back of the head

Question 14

How does intracranial haemorrhage lead to tonsillar herniation?

Answer 14

Accumulation of blood - Raised ICP - Compression of brain - Compression increases to the point that the cerebellar tonsils herniate through the foramen magnum - Death

Question 15

Which artery classically causes extra-dural haemorrhage?

Answer 15

Middle meningeal

Question 16

What is an often misleading feature of extra-dural haemorrhage

Answer 16

Patients may under-go a lucid period where they appear to be recovering only to rapidly deteriorate later

Question 17

Where do sub-dural haemorrhages occur?

Answer 17

Between the dura and arachnoid mater

Question 18

Which blood vessels usually cause sub-dural haemorrhage?

Answer 18

Bridging veins passing from brain surface to large venous channels in the brain
Rotational forces may tear these vessels

Question 19

Where do subarachnoid haemorrhages take place?

Answer 19

Between arachnoid mater and brain

Question 20

What is often the cause of a subarachnoid haemorrhage?

Answer 20

Ruptured cerebral aneurysm

Often seen in association with cerebral contsusions (bruising)

Question 21

What is diffuse axonal injury?

Answer 21

Tearing of nerve fibres in the white matter of the brain

Question 22

What are some common causes of diffuse axonal injury?

Answer 22

High force rotational acceleration
RTAs
Falls from height