Head Injury Flashcards
What is the difference between primary + secondary brain injury due to head injury?
Primary: neuronal damage occuring at time of injury (unpreventable)
Secondary: occurs due to consequence of injury (partly preventable) e.g. oedema, haemorrhage
What is the normal range for adult intracranial pressure?
9-11 mm Hg
What does a patient with an anterior cranial fossa fracture look like? (buzzword)
Racoon/panda eyes
What does a patient with a middle cranial fossa fracture look like? (buzzword)
Battle sign bruising over mastoid area
A coma equates to what score on the Glasgow Coma Score? What are the other features that must be present in coma?
8 or less
No eye opening, no obeying commands, no speech
When should a CT scan be requested in head trauma?
Any one of the following: Suspected skull fracture GCS less than 15 (not orientated) Focal neurological signs Taking anticoagulants
List intensive care management of head injury
Sedation Ventilation BP management Glucose maintenance Temperature maintenance
How does sedation help in management of head injury?
Reduces cerebral metabolic rate, blood flow and ICP
What are the two types of head injury?
Open (penetrating, missile)
Closed (non-missile)
Closed head injury can be split into three types depending on direction of force. What are they?
Acceleration
Deacceleration
Rotation
Define Monro Kielle Hypothesis
Skull is a closed box structure with limited expansion in response to pressure
How is cerebral perfusion pressure calculated?
MAP - ICP
What CPP is aimed for after a head injury?
> 60 mmHg
What type of cerebral autoregulation is damaged in trauma?
Focal cerebral autoregulation
Describe what is meant by ‘ischaemic penumbra’
Ischaemic but still viable cerebral tissue (typically surrounds dense ischaemic core)
What physical findings might you expect after head injury?
Scalp swelling/ laceration
Skull vault fracture
Skull base fracture
What are the three main areas tested in the Glasgow Coma Scale?
Eye opening
Verbal response
Best motor response
What is the function of the GCS?
To assess consciousness
What is the range of scores you can achieve in the GCS?
3 - 15
What score on the GCS is typically achieved in mild head injury?
13 - 15
What are the main 3 causes of mortality in coma as a result of head injury?
Hypoxia
Hypotension
Raised ICP
List the main pathology associated with traumatic intracranial bleeding
Extradural haematoma
Subdural haematoma
Intracerebral haematoma
Traumatic SAH
List management options to treat raised ICP
CSF drain Mannitol Hyperventilation Hypothermia Decompressive craniectomy
What is the mechanism of action of mannitol in treating raised ICP?
Increases microperfusion Reduce oedema (acts as a diuretic)
List the potential late effects of head injury
Post-traumatic epilepsy
CSF leakage (into nose or middle ear)
Cognitive problems ('post-concussive syndrome')List the 5 levels of the Glasgow outcome scale
- Dead
- Persistent vegetative state
- Severely disabled
- Moderately disabled
- Good recovery
Define ‘vegetative state’
Sleep wake cycles are preserved but no other interaction - e.g. eye tracking, response to stimulation
List the characteristic clinical finding on CT scan found in extradural haematoma?
Hyperdense lens-shaped lesion
List the characteristic clinical finding on CT scan found in subdural haematoma?
Crescent-shaped ‘banana’ lesion (acute: hyperdense, chronic: hypodense)
What are the clinical symptoms of extradural haematoma?
Typically young person whol falls and hits head
Brief loss of consciousness followed by an interval and then symptoms - headache, V, CL hemiparesis, IP pupillary dilatation
What are the clinical symptoms of subdural haematoma?
Typically, elderly person who falls or NAI
Acute - reduced consciousness
Chronic - increasing loss of consciousness, headaches, confusion, weak, seizure, gait abnormality, cognitive impairment
What is the classical origin of extradural haematoma?
Middle meningeal artery
What is the classical origin of subdural haematoma?
Cerebral bridging veins
