Head injury Flashcards
What are the commonest causes of head injuries in the UK?
road traffic accidents
alcohol-related incidents - including assaults
Following the primary insult to the head - what secondary insults may follow?
Hypotension
Hypoxia
Infection
Haematoma
Describe the initial assessment process for head injuries
Conscious level assessed using Glasgow coma scale (GCS)
GCS score is out of 15
Describe how GCS scores reflect severity of head injuries
13-15 (high) - Mild injury
9-12 - Moderate injury
3-8 - Sever injury
What significant complications can develop as a result of head injuries?
1.Permanent physical disability
- Post traumatic epilepsy
- Intracranial infection
- Psychiatric illness
- Chronic subdural haemorrhage
- ‘Punch-drunk’ dementia
- Fatal outcome (uncommon)
What types of injuries can affect the scalp?
Similar to those affecting the skin:
- abrasions, bruises, lacerations, incisions (and burns/scalds)
Often obscured by hair
The skull can be split into 2 elements
What are these?
Skull vault (upper part):
- includes frontal bone, squamous temporal bones and occipital bone
- These are all separated by sutures
Skull base (what the brain rests on):
- divided into the anterior, middle and posterior cranial fossae
What are the main types of skull fractures?
Linear skull fracture (+ “hinge” fracture)
Depressed skull fracture
Comminuted (mosaic) - fragmented skull
“Ring” fracture
“Contre-coup” fracture
What is a linear fracture?
Break in a cranial bone resembling a thin line, without splintering, depression, or distortion of bone
Commonly temporo-parietal from blow or fall onto side or top of the head
May continue to skull base to make a “hinge” fracture
What is a depression fracture?
Break in a cranial bone (or “crushed” portion of skull) with depression of the bone in toward the brain
Fragments may damage the meninges, blood vessels and brain
Rarely arises due to falls etc
What conditions may arise post-depression fracture?
Meningitis
Post-traumatic Epilepsy
What is a ring fracture?
fracture line encircling the foramen magnum caused by a fall from height - even if patient lands on feet
caused by skull base and cervical spine being forced together
What is a Contre-coup fracture?
fracturing of the orbital plates (anterior fossa) caused by a fall onto the back of the head
Identify the types of fracture shown
What is an intracranial haemorrhage and what is their association with fractures?
Collective term for any type of Bleeding/accumulation of blood within the skull (cranium)
Intracranial haemorrhages often happen as a result of fractures that have damaged nearby vessels
What are the types of intracranial haemorrhage?
Extradural haemorrhage:
- Between dura and skull
Subdural haemorrhage:
- Beneath dura and above arachnoid
Subarachnoid haemorrhage:
- Beneath arachnoid layer and above the pia (effectively the brain)
Also included are intracerebral haemorrhage & cerebellar haemorrhage but we dont care about those right now
Intracranial haemorrhages caused increased Intracranial pressure - leading to compression of the brain and the symptoms we know and love
Without intervention - how would this progress?
Ultimately - death will occur by compression of the brainstem
This compression is due to herniation of the cerebellar tonsils into the Foramen Magnum
What causes Extradural haemorrhage?
Skull fractures with associated arterial damage
- Rarely due to veins
Classically:
Middle meningeal artery damage - from linear fracture to inner aspect of Squamousarrowed temporal bone
What causes Subdural haemorrhages?
Frequently occurs without skull fracture
Usually caused by bleeding from bridging veins which pass from the surface of the brain to drain into the large venous channels within the dura
Any motion which causes rotational or “shearing” forces can cause the veins to be stretch and torn
What causes Subarachnoid haemorrhages?
Most commonly - Rupture of a cerebral artery (“berry”) aneurysm
- Natural disease (non-traumatic)
AVM - arteriovenous malformation
Trauma:
- SAH frequently seen with Cerebral contusions (bruises to the brain) post-trauma
- “Traumatic Basal SAH” - specific type of SAH caused by
How would Extradural haemorrhage and subdural haemorrhage present?
*Post-trauma to head ± brief period of unconsciousness*
Often - patients with EDH or SDH will have a ‘lucid period’ without neurological symptoms
Followed by rapid Deterioration
How does subarachnoid haemorrhage present?
Sudden, rapid onset of:
- Very severe headache
- Nausea & vomiting
- Syncope/collapse
May have:
- Some aspects of meningism
- Neck stiffness
- Kernig’s sign - indicator or Mening. & SAH
- Papilloedema
- Photophobia etc
What is the clinical significance of Chronic Sub-dural haemorrhage?
This sometimes happens to the elderly
Can cause chronic confusion (and may be mistaken for dementia)
What is cerebral oedema?
Type of intrinsic brain injury characterized by massive brain swelling, increase in ICP and ‘coning’
Common and rapid result of brian injury - especially in children
What is the difference between ‘coup’ contusions and ‘contre-coup’ contusions?
Coup contusions:
- occur when head struck by a heavy blow
- contusion is found directly under the site of impact
Contre-coup contusions:
- caused by a moving head striking a fixed object or unyielding surface
- Contusions found diametrically opposite the site of head impact
What is meant by a ‘diffuse axonal injury’?
lol who knows
