head injury + bleeds Flashcards
primary focal brain injuries
contusion or haematoma
Contusion/bruising on opposite side to primary – due to bouncing off skull
* Coup (adjacent) or contralateral (contre-coup)
o Contracoup tend to be worse
primary diffuse brain injuries
diffuse axonal injury
Severe form of traumatic brain injury due to shearing forces
Occur where density difference is greatest (grey/white interface)
Excitotoxicity + apoptosis
Inflammatory mediator release
a result of mechanical shearing following deceleration, causing disruption and tearing of axons
younger patient, reduced consciousness, difficult to manage
causes of secondary brain injuries
cerebral oedema
ischaemia
infection
herniation
cushing reflex
hypertension + bradycardia
-> often occurs late + is usually preterminal event
a physiological nervous system response to acute elevations of intracranial pressure (ICP),
extradural haematoma vs acute subdural
extradural
- injury with LOC
- recovery with lucid interval then rapid progression of neurological symtpoms
acute subdural = crescent shaped, white
chronic subdural = crescent shaped, dark
CT within 1hr criteria
- GCS <13 on initial assessment
- GCS <15 at 2hrs after injury
- Suspected open or depressed skull fracture
- Any sign of basal skull fracture
- Post traumatic seizure
- Focal neurological deficit – weak on one side
- More than one episode of vomiting
- Suspicion of NAI
- Also if they experienced some loss of consciousness or amnesia since the injury –
o >65yrs
o Coagulopathy
o Dangerous mechanism of injury
glasgow coma scale
Eye opening
o Open spontaneously = 4
o To speech
o To pain
o No eye opening= 1
Verbal
o Orientated = 5
o Confused
o Inappropriate
o Incomprehensible
o No verbal = 1
Motor
o Obeying= 6
o Localizing pain
o Flexing
o Abnormal flexing
o Extending
o No motor response= 1
Severity scale
o Mild = 14, 15 of brief LOC
o Moderate = 9-13
o Severe = 3-8
extradural haematoma
between dura mater + skull
lens/lemon shape on CT
causes
- acceleration-deceleration trauma
- blow to side of head
trauma to the pterion can cause which kind of haematoma
extradural
- rupture of middle meningeal artery
ypical history of extradural haematomas
young patient with traumatic head injury
ongoing headache
has a period of improved neurological symptoms + consciousness
followed by RAPID decline over hours
rupture of bridging veins can cause what type of haematoma?
subdural
- bleeding into the outermost meningeal layer
- between dura + arachnoid mater
acute subdural presentation
cresent white shape on CT
- not limited to cranial sutures - can cross
commonest arounf frontal + parietal lobes
blood is more clotted in one area - big craniotomy
chronic subdural haematoma
elderly falls, assoc with brain atrophy
torn cerebral vain
when becomes chronic becomes more liquified + drain - yellow tinged blood
intracerebral haematoma causes
(within brain itself)
- spontaneous, infarct, tumour
- aneurysm rupture
- vasculitis
drugs - hypertension, diabetes
hypertension = commonest, rupture of microaneurysms
intracerebral presentation + CT findings
presents similarily to ischaemic stroke or decreased consciousness
CT shows hyperdensity (bright lesion) within substance of brain
subarachnoid haemorrhage
between pia mater + arachnoid membrane
(where CSF is)
usually by ruptured cerebral aneurysm
high mortality - low suspicion
more common in black, feale ages 45-70
commonest cause of subarachnoid haemorrhage
rupture of saccular aneurysm (berry aneurysm)
-> most in territory if internal carotid artery
conditions assoc with berry aneurysms
polycystic kidney disease
Ehlers-Danlos
coarctation of aorta
presentation of subarachnoid haemorrhage
sudden onset occipital headache that occurs during strenuous activity - weightlifting, sex
–> thunderclap headache (“hit hard on back of head”)
neck stiffness, photophobia
vision changes
subarachnoid haemorrhage investigations
CT
lumbar puncture
o If CT head is negative, at least 12hrs following onset of symptoms to develop xanthochromia
o Red cell count raised – if decreasing in number of samples probs traumatic from puncture
(Xanthochromia – yellow colour caused by bilirubin, distinguishes from trauma blood)
angiography - once confirmed to locate source
management of subarachnoid haemorrhages
in accordance of causative pathology
intracranial aneurysms -
- coil or craniotomy + clipping
- nimodipine -> prevents vasospasm, CCB targeting brain vasculature
different types of brain herniation
subfalcine - down under falxi cerebri
uncal - part of temporal lobe moving medially
central/coning - through foramen magnum, BAD
transcalvarial - skull fracture, pushing out of skull
effect of uncal harniation on pupils
compression of oculomotor nerve leads to ipsilateral dilated pupil -> blown
brain death
must be done by 2 doctors
- no pupil response
- no corneal reflex
no motor respone
no vestibuloocular reflex
no gag/cough reflex
no respiration
