Pathology of Head Injury Flashcards
What are the basic types of injury at the skin level? [5]
- Bruises (Contusions)
- Abrasions (Grazes)
- Lacerations (Tears/splits)
- Incisions (Cuts)
- Thermal Injuries
What causes a bruise?
Blunt Force trauma causes the injured vessel to leak blood
How can bruising help us determine what happened?
The pattern of bruising can help us tell what happened to the person
How does a black eye happen? [2]
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
Whats the difference between lacerations and incisions?
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
What are the types of skull fracture? [4]
- Ring fracture
- Fissure Fracture
- Depressed (SIGN) Fracture
- Hairline Fracture
Whats the difference between ring/fissure/hairline fractures
Hairline fractures are a result of low force and tend to heal easily as they dont communicate outside and are stable
Fissure fractures occur on more force
Ring fractures are a result of a lot of force, the fracture travels all the way round the skull, often taking in foramen and sutures on its way
What is a depressed Fracture?
Bone forced inward by the injury which may damage, bruise, expose brain.
Generally the bone is comminuted
Comminuted?
Broken into several pieces
What layer of meninges do veins traverse?
The subdural space from arachnoid to dural sinuses
Called Bridging veins
What are the types of Intracranial Haemorrhages?
- Epidural
- Subdural
- Subarachnoid
- Intracerebral
What type of intracranial haemorrhage is most associated with skull fractures?
Epidural
The fracture damages the meningeal arteries, most often the Middle Meningeal Art through the temporal bone
How does a subdural haemorrhage generally occur?
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
Subarachnoid haemorrhages can be spontaneous (e.g. aneurysm) or traumatic, What causes a traumatic one?
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
What are the types of intracerebral injury? [3]
- Cortical Contusion
- Intracerebral Haemorrhage
- Diffuse Axonal Injury
How does a cortical contusion occur?
Part of a depressed fracture, sudden termination of head movement or impact on the surface of the skull
What are coup and contracoup contusions?
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
What are the types of intracerebral haemorrhage? [2]
Atraumatic
- Due to hypertension, tumours, Arteriovenous anomalies etc
Traumatic
How does diffuse axonal injury occur? [2]
Extreme force causes many superficial and deep haemorrhages
This tends to cause rapid death or brain damage
Head injury: NICE guidance on investigation
Indications for CT head immediately [7]
- GCS < 13 on initial assessment
- GCS < 15 at 2 hours post-injury
- suspected open or depressed skull fracture.
- any sign of basal skull fracture (haemotympanum, ‘panda’ eyes, cerebrospinal fluid leakage from the ear or nose, Battle’s sign).
- post-traumatic seizure.
- focal neurological deficit.
- more than 1 episode of vomiting
CT head within 8 hours of the head injury: for adults with any of the following risk factors who have experienced some LOC or amnesia since injury: [4]
- age 65 years or older
- any history of bleeding or clotting disorders
- dangerous mechanism of injury (a pedestrian or cyclist struck by a motor vehicle, an occupant ejected from a motor vehicle or a fall from a height of greater than 1 metre or 5 stairs)
- more than 30 minutes’ retrograde amnesia of events immediately before the head injury
Indications for CT head for patients on anticoagulant?
If a patient is on warfarin who have sustained a head injury with no other indications for a CT head scan, perform a CT head scan within 8 hours of the injury.
