Bleeds in the brain - EDH, SDH, SAH, ICH, DAI Flashcards
what are the 5 main types of bleeding into the brain
extradural subdural subarachnoid intracerebral (diffuse axonal injury)
what does each type of bleed look like on a CT scan
ED - lens shape
SD - ellipse shape (banana)
SA - best seen around circle of willis, dense grey outline
IC - lump of blood somewhere in the brain (common in basal ganglia/thalamus area
diffuse axonal injury - brain looks “fuzzy”, loss of distinction between grey/white matter
how does blood show up on a CT
acute blood - white
old blood - black
actively bleed site - dusk sign, grey
what type of bleed is an EDH and how does it occur
high pressure arterial bleed
high force mechanism of injury
- dura firmly attached to the bone
- small arteries run through this space
- when force shears the dura away from the bone these arteries bleed
what area/vessel is most at risk of an EDH
temple area - pterion is weak
middle meningeal artery at risk
what is the general presentation/progression of a patient with an EDH
concussed
then appears well
bleed continues (high pressure arterial)
patient worsens when space expands between bone and dura - starts pushing into brain
what is the management of an EDH
emergency - burr hole or small craniotomy to remove blood/release pressure
early detection = better recovery
what type of bleed is a SDH and how does it occur
low pressure venous bleed
small trauma mechanism
- veins go between dura and arachnoid layers (subdural space)
- stretching/increased pressure across these veins lead to tears
- bleeds
what is the general presentation/progression of a patient with a SDH
small trauma (patient might not even notice it) causes bleed - takes a long time to present clinically
might have multiple bleeds before getting noticeable signs/symptoms
on CT can show “acute on chronic SDH” from multiple small traumas over time
who is at risk of a SDH
people with atrophy of the brain
eg elderly, dementia, alcoholics
atrophy of the brain leads to stretching of the veins within subdural space - increases likelihood of ruptures
what is the treatment of a SDH
if big can drain with a burr hole
if large and old can insert two small holes and do a wash out of broken down blood
what type of bleed is a SAH and how does it occur
high pressure arterial bleed
can occur from head injury or spontaneous aneurysm
- bleeding between the arachnoid and pia
- blood accumulates in the SA space around the curvatures of the brain
one type of haemorrhagic stroke
what is the general presentation/progression of a patient with a SAH
*sudden onset thunderclap headache
N/V
meningism (irritation of the meninges) - headache, neck stiffness, photosensitivity
what are some causes and risk factors of a SAH
trauma
aneurysm (more common in younger patients)
HTN polycystic kidney disease smoking alcohol cocaine use
where is the most common place for an aneurysm
where the arteries bifurcate eg anterior communicating artery in the circle of willis
what are the investigations and management of a SAH
CT head within 6 hours of onset
CT angiogram
MRI
investigations guide management
- lower BP eg labetalol
- prevent vasospasm eg CaCB (nimodipine) for 21 days
- coiling (intravascular) to prevent bleeding
reduce risk factors
what are some complications of a SAH
hydrocephalus - needs a shunt to drain
vasospasm - can lead to ischaemic stroke
what type of bleed is an ICH
high pressure arterial bleed
one type of haemorrhagic stroke
- ie bleeding into the brain
where is it most common for an ICH to occur
thalamus and basal ganglia
what are risk factors for an ICH
HTN
anticoagulants
blood thinners
what is a complication of an ICH
can spread to the ventricles causing hydrocephalus
what is the management of an ICH
if spread to ventricles - drain to outside
craniotomy to relieve pressure in extreme cases
antihypertensives
secondary prevention to control BP
what is a diffuse axonal injury
shearing of tiny vessel between the white an grey matter - leads to petechial haemorrhage
how does a DAI occur
high velocity impact
shaken head (paeds - “shaken baby”)
white matter and grey matter have different densities
- one moves faster than the other
- axons crossing between the two break
- very tine blood vessels break
- widespread petechial haemorrhage on top of multiple white and grey matter lesions
causes LOTS of swelling - can be very difficult to treat
what complications can a DAI lead to
increased pressure on the brain due to extensive swelling throughout
- can lead to brainstem herniation as its pushed down through the foramen magnum
- can cause ischaemia and pressure damage
- common cause of persistent vegetative state
what is a normal value for ICP and when should you start to worry
~10 normal
>20 worry
what regulates the ICP
systolic BP - cerebro autoregulation can maintain a normal ICP between systole 50-150
outside of this auto regulation fails = symptoms
what can cause raised ICP and therefore autoregulation to be put off
anything that raises pressure
- bleeding
- mass/tumours/cysts
- oedema
DAI management
very difficult - try reduce raised ICP from swelling, palliative
