Head trauma Flashcards
CSF production, circulation and reabsorption
Produced by choroid plexus in lateral, 3rd and 4th ventricles
Reabsorbed by arachnoid granulation in superior sagittal sinus
3 layers of meninges
Which blood vessels are responsible for extradural bleed
Meningeal arteries, especially middle meningeal artery
Which blood vessel responsible for subdural bleed
Bridging veins
Which blood vessels are responsible for intra-cerebral bleed (subarachnoid haemorrhage)
Major blood vessels at the base of the brain
Brainstem parts
Midbrain
Pons
Medulla
Function of midbrain and upper pons
Reticular activating system (state of alertness)
Function of medulla
Cardiorespiratory centre
Tentorium cerebelli
Separates intracranial cavity into supratentorial and infratentorial
Midbrain passes through tentorial hiatus
Which nerve could be compressed against the tentorium
Oculomotor leading to a blown pupil (carries PSN, if impaired, eye only gets sympathetic)
Which part of brainstem herniates through tentorium due to raised ICP
midbrain
Which part of brain herniates through tentorium due to raised ICP
the medial part of temporal lobe known as uncus
Sx of uncus herniation
Ipsilateral pupillary dilatation (PSN fibers of CN3)
Contralateral hemiparesis (corticospinal tract of the midbrain)
Reduced GCS (reticular system)
Normal ICP
10mmHg
What sustained ICP is associated with poor outcome
>22mmHg
Monro-kellie doctorine
Total volume of intracranial content is constant
Total volume = Venous volume + arterial volume + brain + CSF
Cerebral perfusion pressure (CPP) formula
CPP = MAP - ICP
At what MAP is cerebral blood flow autoregulated (constant)
MAP of 50-150 mmHg
GCS depending of severity of traumatic brain injury (TBI)
Mild 13-15
Moderate 9-12
Severe 3-8
When calculating GCS and there’s discrepancy between left and right side, which score do you use
The best motor response (the higher score)
Types of skull vault (roof) fracture
Linear vs stellate
Depressed vs non-depressed
Clinical signs of basilar skull fracture
Periorbital ecchymosis (raccoon eyes)
Retroauricular ecchymosis (Battle’s sign)
Rhinorrhoea (CSF from nose)
Otorrhoea (CSF from ear)
CN7,8 dysfunction
Classic epidural haematoma presentation
Lucid period before deterioration
Which region of the brain often affected by epidural bleed
Temporoparietal