Head and spinal injury Flashcards
How are head injuries classified?
Based on severity
- minor: GCS 13+
- moderate: GCS 9-12
- severe: GCS 8 or less
Based on morphology of skull fracture e.g. vault, basal
Based on type of intracranial lesion e.g. focal, diffuse
How are traumatic brain injuries classified and how can each be prevented?
- primary brain injury: happens at the time of the injury and can only prevented by preventing the incident from occurring in the first place (e.g. speed limits) or by damage limitation techniques (e.g. cycle helmets)
- secondary brain injury: damage resulting from complications of the primary injury, prevented by timely and effective management in pre-hospital and secondary care
What are examples of primary brain injuries?
- cerebral laceration
- cerebral contusion
- dural sac injury
- diffused axonal injury
- skull fractures
What are examples of secondary brain injuries?
- ischaemic hypoxia
- hypovolaemic hypoxia
- raised ICP
- metabolic abnormalities
- infection
- pyrexia
What is cerebral perfusion pressure?
a proxy indicator for cerebral blood flow
CPP = MAP - ICP
What is a normal ICP?
10mmHg
What is a Cushing’s response (triad), in relation to foramen magnum / tonsillar herniation?
- high BP
- Bradycardia
- abnormal breathing
What history findings would suggest risk of intracranial bleed?
- high energy injury
- history of bleeding or clotting disorders (including liver disease)
- anticoagulant therapy
- current drug or alcohol intoxication
- LOC
- amnesia for events before or after injury
- persistent headache post injury
- vomiting episodes since injury
- seizure since injury
What examination findings would suggest risk for intracranial bleed?
- GCS less than 15
- suspicion of skull fracture or penetrating head injury
- any focal neurological deficit since injury
What are the signs of basal skull fracture?
- panda or raccoon eyes
- battles sign: mastoid bruising
- haemptympanum
- CSF rhinorrhoea or otorrhoea
- LMN facial palsy
What are the classic features of an extradural haematoma?
- biconvex area of arterial bleeding, typically from middle meningeal artery
- typically temporal or temporoparietal
- likely to have a skull #
- classical lucid interval between injury and deterioration due to raised ICP
What are the classical features of a subdural haematoma?
- venous bleeding which covers the surface of the brain to form a present shape on imaging
- results from tearing of riding beans between dura and brain
- more common in older people and alcoholics, prognosis worse than extradural as affected population are generally less healthy to begin with
What are the classical features of an intracerebral haematoma?
- bleeding within the brain itself
- called “coup” if the affected region is directly related to the injury, or “contre-coup” if on the opposing side to the injury and occurs due to movement of brain within vault
- symptoms related to anatomical location of the bleed
What are the classical features of a diffuse axonal injury?
- diffuse microscopic changes due to shearing forces to neurons
- usually caused by rapid acceleration/deceleration
- associated with low GCS, motor posturing, autonomic dysfunction, hypertension, hyperpyrexia
- CT may appear normal in early stages
Pain can led to raised ICP. True or false?
True
