Head trauma Flashcards
What’s the difference between missile and non-missile head injury?
Missile: penetration of skull or brain
Non-missile: other, far more common
How can you classify head traumas by distribution?
Focal: local, in one site
Diffuse: widespread
What is the difference between primary and secondary damage in a head injury?
Primary: the immediate effects of the trauma
Secondary: the problems that present some time after the trauma, like infection, effects of hypoxia etc.
Name some types of focal brain damage?
Lacerations Contusions: bruises Haemorrhage Fracture Infection
Name some types of diffuse brain damage?
Diffuse axonal injury
Diffuse vascular injury
Hypoxia - ischaemia
Swelling
What are the problems that a skull fracture can cause?
Haematoma + haemorrhage
Infection
Aerocele: pocket of air in the brain
Name the types of haemorrhage that can be caused by head injury?
Epidural
Subdural
Subarachnoid
Intracerebral
Cerebellar
What is a contusion?
A superficial bruise of brain
What is meant by:
- coup
- contre coup?
Coup: contusion at the site of the blow to the head
Contre-coup: contusion at other sites, due to the movement of the brain being out of sync with the skull after a blow to the head
What causes diffuse axonal injury?
Anything that could damage the axons
Ischaemia
Tumours
Demyelination (MS)
A blow to the head
What would you see on a CT of someone with diffuse vascular injuries?
Multiple petechial haemorrhages throughout the brain
Why is brain swelling bad?
Because the brain is kept inside a hard, unstretchable skull
If it swells intracranial pressure rises compressing the brain and damaging it
Or causing herniation, coning
What is herniation of the brain?
When swelling of the brain causes it to shift into places it shouldn’t
Like one hemisphere pushing over the midline
Or the brain pushing down onto brainstem (coning)
What two types of missile injury are there?
Penetrating: the bullet goes into skull and stops there
Perforating: the bullet goes into the skull and out the other side
What are the risks associated with penetrating injuries?
High risk of infection as bullet has made a track as it has embedded in the brain
Focal damage
Bleeding
Epilepsy
What is chronic traumatic encephalopathy (CTE)?
Progressive degenerative disease that affects people who have suffered from repetitive mild traumatic brain injury
Who gets (CTE)?
Sports people
- boxers
- wrestlers
- rugby
Clinical features of CTE?
Disorientation
Dizziness
Headaches
Memory loss
Erratic behaviour
Progressive dementia
Slowing of muscular movements Tremors
Suicidality
What is the Glasgow Coma Scale?
Measures level of consciousness of a patient
What is the AVPU scale?
What does it stand for?
A quicker version of GCS, measures level of consciousness of patient more in an emergency setting
Alert
Voice (responds to)
Pain (responds to)
Unresponsive
Why is it a good idea to ventilate an agitated patient with a head injury?
If they are agitated and stressed their blood pressure will be high
This will cause even more damage to the brain
It may raise ICP even more
They are better ventilated as then they are still and calm
What does ICP stand for?
Intracranial pressure
What is meant by ‘secondary head injury’?
Injury to the brain that results from another injury
Such as hypoxia of the brain or shock
What does a mini neurological exam involve?
Glasgow coma scale score
Lateralising signs
Pupils
What are lateralising signs?
Signs that help you to localise a CNS pathology
For example receptive dysphasia would indicate a lesion in the region of Wernicke’s area
What drug should you give to someone as soon as you can after a head injury?
Mannitol a hyperosmotic agent
Sucks water out of the brain system, managing the swelling for a few hours
What does Mannitol do?
Sucks water out of the brain system
Managing the swelling for a few hours
What are Burr holes?
Hole drilled into the skull in which a tube is inserted through a hole to help drain the haematoma
What is a craniotomy?
A section of the skull is temporarily removed so the surgeon can access and remove the haematoma
What is a craniectomy?
Removal of part of the skull to relieve pressure in the cranium and allow the brain to swell
Why do you need to be concerned about minor head injuries?
They are very common
About 2% of people with a minor head injury will develop complications
It is hard to know which ones!
Which people with minor head injuries should you be extra concerned about?
Those on aspirin, warfarin
GCS score of 13-14
What are some classic warning signs of a head injury that has progressed to something more severe?
Changes in level of consciousness
Seizures
Bleeding or watery discharge from ears or nose
What is a basal skull fracture?
A fracture of the base of the skull
What are some signs of a basal skull fracture?
Sub conjunctival haemorrhage
Bilateral periorbital haematoma: ‘Panda eyes’
Battle’s sign: bruising behind ears
Blood leaking from ears
What is Battle’s sign?
Bruising behind the ear
What complication can occur from a basal skull fracture?
Meningitis
List some common pitfalls and things doctors miss in relation to head injuries?
Missed injury: like a neck injury or one obscured by hair
Not taking obs frequently enough
Loss of CSF via a leaking wound post craniotomy
Spinal reflexes mistaken for movement
Vertebral artery dissection
