Pathology of Head Injury

Question 1

What are the basic types of injury at the skin level?

Answer 1

• Bruises (Contusions)
• Abrasions (Grazes)
• Lacerations (Tears/splits)
• Incisions (Cuts)
• Thermal Injuries

Question 2

What causes a bruise?

Answer 2

Blunt Force trauma causes the injured vessel to leak blood

Question 3

How can bruising help us determine what happened?

Answer 3

The pattern of bruising can help us tell what happened to the person

Question 4

How does a black eye happen?

Answer 4

Blood tracts to and collects around the eye when there injury to the brow or forehead.
A direct injury to the eye is quite unlikely

Question 5

Whats the difference between lacerations and incisions?

Answer 5

A laceration is a blunt force injury causing tears and splits in the tissue, which will often be ragged and bridged by stronger tissues

An incision is a sharp force wound (knife, glass etc) causing a neat, unbridged wound

Question 6

What are the types of skull fracture?

Answer 6

• Ring fracture
• Fissure Fracture
• Depressed (SIGN) Fracture
• Hairline Fracture

Question 7

Whats the difference between ring/fissure/hairline fractures

Answer 7

Hairline fractures occur on low force and tend to heal easily as they dont communicate outside and are stable

Fissure fractures occur on more force

Ring fractures occur on a lot of force, the fracture travels all the way round the skull, often taking in foramen and sutures on its way

Question 8

What is a depressed Fracture?

Answer 8

Bone forced inward by the injury which may damage, bruise, expose brain.

Generally the bone is comminuted

Question 9

Comminuted?

Answer 9

Broken into several pieces

Question 10

What layer of meninges do veins traverse?

Answer 10

The subdural space from arachnoid to dural sinuses

Called Bridging veins

Question 11

What are the types of Intracranial Haemorrhages?

Answer 11

• Epidural
• Subdural
• Subarachnoid
• Intracerebral

Question 12

What type of intracranial haemorrhage in most associated with skull fractures?

Answer 12

Epidural

The fracture damages the meningeal arteries, most often the Middle Meningeal Art through the temporal bone

Question 13

How does a subdural haemorrhage generally occur?

Answer 13

When the head is moving fast and impacts something, stopping suddenly.

The brains momentum keeps it moving inside the skull, pulling on and bursting the bridging veins

Question 14

Subarachnoid haemorrhages can be spontaneous (e.g. aneurysm) or traumatic, What causes a traumatic one?

Answer 14

A blow to the neck or the chin causes the head to twist and extend, often in RTAs.

Its tearing of the vertebral arteries as they temporarily leave the C-spine

Question 15

What are the types of intracerebral injury?

Answer 15

• Cortical Contusion
• Intracerebral Haemorrhage
• Diffuse Axonal Injury

Question 16

How does a cortical contusion occur?

Answer 16

Part of a depressed fracture, sudden termination of head movement or impact on the surface of the skull

Question 17

What are coup and contracoup contusions?

Answer 17

Coup is a bruising at the site of impact

Contracoup is bruising on the opposite region of the brain as it impacts the skull when moved by force of impact

Question 18

What are the types of intracerebral haemorrhage?

Answer 18

Natural
Due to hypertension, tumours, Arteriovenous anomalies etc

Traumatic

Question 19

How does diffuse axonal injury occur?

Answer 19

Extreme force causes many superficial and deep haemorrhages

This tends to cause rapid death or brain damage