Stroke 3 Flashcards
reversal is only possible in what type of stroke?
ischaemic
only if done v quick
other than this, can only do secondary prevention to prevent another stroke
2 hyperacute treatments for ischaemic stroke?
thrombolysis (<4.5 hrs)
thrombectomy (<6 hrs)
types of secondary prevention?
antiplatelets anticoagulants statins anti hypertensives diabetic management lifestyle management MDT approach to rehab
how do you choose secondary prevention?
determine what caused initial stroke and prevent it happening again
most important risk factor for stroke?
hypertension
types of antiplatelets?
aspirin
clopidogrel
dipyridamole MR
ticagrelor and prasugrel (not used much in stroke disease)
when are antiplatelets used?
only ischaemic stroke
small vessel events and atheroembolic infarcts/TIAs
risks of antiplatelets after ischaemic stroke?
haemorrhagic transformation
will cause inflammation and oedema which causes problems
what kinds of ischaemic stroke are antiplatelets used for?
only ones where clot has formed due to platelet aggregation rather than coagulation factors
how is aspirin used after ischaemic stroke?
300mg for at least 2 weeks
after 2 weeks can either continue aspirin but drop down to 75mg along and add dipyrimadole 200mg 2X day OR change to clopidogrel 75mg alone
what if genuine allergy to aspirin?
clopidogrel 300mg straight after stroke (single dose) then 75mg thereafter (clopidogrel much more potent)
if patient had smaller stroke with low neurological score, which option is used?
aspirin + clopidogrel
what kind of ischaemic strokes are anti-coagulants used for?
large vessel cardioembolic paradoxical embolic venous infarcts (only clots formed of coagulation factors, not formed within arteries)
types of anticoagulants?
heparin (fractioned and unfractioned)
warfarin
DOACs (factor 10 or factor 2 inhibitors)
is heparin used in stroke?
no
increases bleeding risk too much
most common stroke requiring A/C?
cardioembolic (from AF)
what does INR describe?
comparing clotting ability to normal
INR 2 = clot will take twice as long to clot as a normal person?
DOACs vs warfarin?
DOACs have less risk of bleeding complications
benefits of warfarin?
cheaper
all complications known about
has an antidote
effects can be measured quickly with INR so can thrombolyse warfarin patients if their INR is <1.5
drawbacks of warfarin?
often INR blood testing
causes very variable INR
dose changes so difficult if any cognitive impairment present
benefits of DOAC?
less risks
no blood tests needed
same dose every day
drawbacks of DOAC?
anticoagulation effects dont last long so if you miss a single dose the INR can change within hrs
no quick blood test (effects measured with PTT which takes a long time) so if patient has an ischaemic stroke while taking DOAC you cant thrombolyse bc its too risky without knowing
when do you start anticoagulation?
depends on size of stroke
small = quicker
large = later on (10-14 days after)
management of BP after ischaemic stroke?
a lot of evidence for BP management after a few weeks
less evidence about whats best in acute phase so BP not really reduced in acute phase
management of BP in haemorrhagic stroke?
more evidence for reducing BP in acute phase
reduces haematoma expansion and resultant brain damage
why is BP not really managed often in acute phase?
bc high BP can help increase perfusion to the brain
controlled in some cases though (eg if patient is being thrombolysed after ischaemic stroke or if BP is extremely high)
which antihypertensives are preferred in stroke?
ACEi / ARBs
thiazides
(non-selective beta blockers
(if theyre already on some antihypertensive regime which is controlling BP then dont change it after stroke)
when are statins used in stroke?
atheroembolic/small vessel strokes
more likely to be associated with dyslipidaemia
when might MRI be used?
if very short lived symptoms?
how do you choose imaging type?
always do a CT, then do MRI if CT doesnt explain whats going on
which scan is best to identify acute haemorrhage?
CT
MRI not good for acute haemorrhage
how can acute infarcts be seen on CT/MRI?
only show on CT 4-5 hrs after (may see some hyperacute changes)
can see infarct within minutes in diffusion weighted MRI
small infarcts on imaging?
CT can miss small infarcts esp if significant small vessel disease and in posterior fossa
MRI less likely to miss any sized infarcts
which scan can differentiate between acute haemorrhage and acute infarcts the best after a few weeks?
CT unable to differentiate (esp if small)
MRI excellent at picking up old haemorrhages
specific pathology on imaging?
CT shows fairly obvious pathology like large infarcts, SOLs, mets, large abscesses etc
MRI has excellent anatomical detail
oedema on CT?
takes away variation in density
so cant differentiate between grey and white matter
infarct on CT?
darker area
can have white spots in darker area if haemaorrhagic transformation present
how can clot be seen on CT?
hyperdense vessel (appears white) usually only seen very soon after infarct before damage to brain can be seen
diffusion sequence MRI is best for what?
showing ischaemic infarct
shows as bright white area
(uses diffusion of water)
acute bleed on CT?
white
long term bleed on CT?
black
