stroke Flashcards
define TIA time scale?
<24hrs
most TIA are less than how long?
<1hr
define stroke?
Vascular compromise causes neuro deficit >24hrs.
Vascular compromise in the brain can be broadly split into what two categories.
how common are each at causing strokes?
-%
ischaemia 85%
haemorrhage 15%
why is Brain so susceptible to ischaemic damage?
can only do aerobic respiration
stroke pt can not take oral meds, what common symptom is the cause of this?
what tube can you use instead to deliver meds?
Dysphagia
NG tube
how can brain haemorrhage lead to a secondary stroke?
Haemorrhage, pool of blood hits on other blood vessels –> pool of blood has breakdown products –> these hit on vessels causing vasospasm –> secondary stroke
define ischaemic penumbra?
brain tissue will progress to infarction because of stroke but is still salvageable if perfused.
how long will ischaemic penumbra tissue last?
few hours
Broca’s and Wernicke’s is supplied by what artery?
MCA - middle cerebral artery
which protein that causes dementia can cause cerebellar bleeding.
how does it do this?
Amyloid
amyloid protein stiffens brain so bleeds more easily
which endocrine blood abnormality can mimic stroke symptoms?
Hypoglycaemia
why might a Toxicology screen be useful in pt with suspected stroke?
because intoxicants can mimic stroke symptoms
Smoking & HTN can cause what structures of brain to bleed?
basal ganglia
how will a superficial MCA stroke differ from a deeper MCA stroke in terms of symptoms?
superficial MCA stroke - symptoms more focal, .e. just arms, or just face, or just tongue effected.
deeper MCA stroke - arms, face & tongue all effect, not focal.
Vascular causes of stroke in the brain can be broadly split into what two categories.
how common are each at causing strokes?
-%
ischaemia 85%
haemorrhage 15%
blood clot risk factors for stroke?
blood clots that cause stroke can be split into two categories?
10
o HTN o Old Age o Atherosclerotic plaques (high LDL) o Diabetes o Smoking o Atrial fibrillation - creates emboli o Aortic dissection o Sickle cell disease o Polycythaemia o Hypercoagulability
thrombotic or embolic
Haemorrhage risk factors for stroke?
-8
o HTN o Age o Trauma o AV malformation o HTN o Anticoagulation therapy o Berry aneurysm o Cerebra amyloid
which ethnicity is at risk of HTN and thus stroke?
afro-carribean
why is ↑Age a risk factor for stroke?
with age:
walls become weaker = haemorrhage.
Walls become stiffer = HTN
how does HTN cause haemorrhage stroke?
-step by step
high pressure RBC bang on artery walls, –> walls swell out to make aneurysm –> high BP will make aneurysm burst –> bleeding.
how does HTN cause ischaemic stroke?
-step by step
based on this pathophysiology what kind of stroke is this?
small arterioles cannot take the pressure > thicken their walls to compensate > small lumen > eventually infarct –> called a lacunar stroke
define AV malformation?
how can this cause haemorrhage stroke?
direct connection between arteries and veins
high pressure arteries push blood into low pressure veins (no dampening capillaries), so they bleed.
how can hyperglycaemia cause ischaemic stroke?
-step by step
high glucose causes oxidative stress –> walls damaged, LDL will fill in the gap in the wall
–> atherosclerotic plaque.
if pt is having stroke why do you never give pt water with glucose in it.
because high glucose during a stroke will exacerbate stroke
what effect does polycythaemia have on blood clotting rate?
increases your rate of blood clotting
pt has Brainstem infarct.
what are the differentiating features?
-2
quadriplegia + lock-in syndrome
which endocrine meds are a risk factor for stroke?
-2
why?
HRT or pill
oestrogen increases coagulability
how does hypovolaemia impact on an acute stroke?
worsen ischaemic penumbra
how does hypervolemia impact on an acute stroke?
-3
more cerebral oedema, hyponatraemia and cardiac failure
differentiating feature of ACA stroke?
Leg problems
differentiating features of posterior communicating artery stroke (on the left side)?
3
o L sided ptosis
o Double vision
o Pupil dilated
differentiating features of MCA stroke?
-3
Arm, face problems
Broca gone
Wernicke gone
how will Broca and Wernicke aphasia sound?
Broca gone - like Yoda no fluid speech
Wernicke gone - no meaningful speech
differentiating feature of PCA stroke?
what does PCA stand for?
Vision loss
posterior cerebral artery
Left occipital lobe ischaemic.
how does this effect vision?
right visual field of both eyes lost
acronym to remember presentation of a cerebellum stroke
DANISH
Right occipital lobe ischaemic.
how does this effect vision?
left visual field of both eyes lost
what does DANISH stand for?
o Dysdiadochokinesia
o Ataxia
o Nystagmus
o Intention tremor – point to finger, point to nose. Past pointing.
o Speech – slurred/staccato
o Hypotonia
red herring to intention tremor?
basically things that might look like intention tremor but are not
diplopia + motor weakness
how can you test intention tremor?
ask to point to finger and point to nose and check for:
shaking
past pointing
define dysdiadochokinesia.
how can you test for this?
inability to perform rapid alternating muscle movements
mr bean clap
define nystagmus?
involuntary rhythmic eye movements
someone has DANISH presentation.
where is there stroke?
cerebellum
general stroke symptoms?
-7
motor weakness speech problems (dysphasia) face "melts" swallowing problems visual field defects balance problems initial stroke hypertonic. Weeks later hypotonic.
most common type of visual field defect in stroke?
homonymous hemianopia
someone has stroke and loses balance
where is there stroke?
cerebellum
TIA symptoms resolve within how long?
24 hours
1st line imaging?
Non-contrast CT head
to assess internal carotid arteries, what Ix do you use?
Doppler US
to assess vertebral artery, what Ix do you use?
CT angiogram
Non-contrast CT head is contraindicated.
what is the alternative?
MRI head
main thing you are looking for in ECG, think of cause?
Atrial fib
what do you look for in bloods?
-6
Hba1c
hypoglycaemia
lipids clotting screen (INR),
hyponatremia ,
CRP
on CT sometimes CSF and blood clot can look the same colour.
so what unit do you use to distinguish between the two?
what value would indicate a clot?
Hounsfield unit
Hounsfield unit 70 = clot
which imaging can let you identify if it is ischaemic or haemorrhagic stroke?
CT
pt is having a stroke.
in acute Mx what needs to be stabilised?
-3
fluids, glucose, BP
pt is having a stroke from a blood clot.
what drug do you give acutely?
- name
- dose
- how long
should this drug not stop the clot, what intervention do you take now 2nd line?
- name of therapy
- name of drug in this therapy
Aspirin 300mg for 2 weeks
Thrombolysis - alteplase
pt is having a stroke from a blood clot.
when should you lower BP?
only If there is emergency HTN
pt is having a stroke from a blood clot.
why do you usually not lower BP?
because if BP is too lowered you inhibit collateral perfusion.
if pt having thrombolytic therapy how low must be BP be?
why?
BP must be <185/110
↑↑↑BP effects thrombolysis.
pt is having a stroke from a blood clot.
what drug do you give acutely?
- name
- dose
- how long
should this drug not stop the clot, what intervention do you take now 2nd line?
- name of therapy
- name of drug in this therapy
Aspirin 300mg for 2 weeks
Thrombolysis - alteplase
pt had a stroke from a blood clot, now resolved and acute Mx is done.
what drug is given to prevent future clots and strokes?
- drug name
- strength
- frequency
- how long
2nd line drug is above is CI?
- drug name
- strength
- frequency
3rd line drug is above is CI?
Clopidogrel 75mg daily lifelong
Aspirin 75mg daily
Dipyridamole
pt had a stroke from a blood clot, now resolved and acute Mx is done.
one of pt’s risk factors is high LDL.
what drug do you give to address this?
- class
- strength range
Statin 20-80mg
pt had a stroke from a blood clot, now resolved and acute Mx is done.
one of pt’s risk factors is atrial fib.
what 2 drugs do you give to address this?
-name
Apixaban + warfarin
main SE of alteplase?
haemorrhage
when is alteplase contraindicated?
-3
active brain haemorrhage
any history of brain haemorrhage
uncontrolled HTN
what group is clopidogrel in?
Antiplatelet drugs
side effects of clopidogrel?
-3
- Dyspepsia
- Bleeding
- Diarrhoea
moa of clopidogrel?
inhibition of ADP-dependent activation of
the GPIIb/IIIa receptor thus stopping platelet
aggregation
aspirin group?
Antiplatelet drugs
medical name for aspirin?
acetylsalicylic acid
moa of aspirin?
-step by step
Irreversible cyclooxygenase enzyme inhibition –> stops prostaglandins and thromboxanes synthesis –> ↓synthesis & ↓ platelet aggregation.
aspirin SE?
- 4
GI bleeding, ulcer, HTN, Reye’s syndrome
Dipyridamole group?
antiplatelet medicine
pt having haemorrhagic stroke.
where do you admit pt to?
- and why?
who do you refer to?
Admit to neurocritical care - because ICP needs monitoring
refer to neurosurgeon ASAP
pt having haemorrhagic stroke.
cause is a berry aneurysm bleed.
how do you treat?
– interventional radiologist goes in from femoral artery and clips it
pt having haemorrhagic stroke.
general goal of surgery if indicated?
decompression
pt having haemorrhagic stroke.
ICP is raised.
what three Mx step do you do initially?
raise head (30°) intubate with hyperventilation IV hypertonic Saline
pt having haemorrhagic stroke.
will most pts have surgery or conservative (i.e. drug) Mx?
conservative
pt having haemorrhagic stroke.
what is general conservative Mx in terms of drugs?
stop warfarin, aspirin, clopidogrel
pt had a stroke.
DVLA rules on driving?
when can you start driving again and on what condition?
1 month no driving
After 1 month if doctor is happy with progress you can drive.
pt had a TIA.
DVLA rules on driving?
when can you start driving again and on what condition?
1 month no driving
After 1 month if doctor is happy with progress you can drive.
pt had multiple TIAs in short period.
DVLA rules on driving?
No driving for 3 months
pt had a stroke or TIA and drives a heavy good vehicle.
DVLA rules on driving?
when can you start driving again and on what conditions?
1 year no driving
After 1 year can drive again if no significant neuro symptoms and no significant RF
why is High Ca2+ a problem in the brain?
High Ca2+ is toxic to neurons –> High Ca2+ makes free radicals & ROS = neurons die
how can brain ischemia cause High Ca2+ in the brain?
no O2 to make ATP pump work which normally takes Ca2+ out of neuron –> so Ca2+ builds in neuron
what happens to BBB in stroke?
why?
what risk does this propose?
step by step
BBB leaky
Ischaemia + inflammation from stroke will make the tight BBB leaky
Protein + water in blood will leak from blood vessels into brain tissue –> causing oedema –> oedema can push brain so herniation
Hypoglycaemia symptoms that can mimic stroke?
-4
weakness
numbness
trouble speaking
vision problems
which area is the inner ear?
wernicke
which area is the inner voice?
broca
how does broca aphasia sound?
like yoda; not fluent, speech halting
is wernicke speech fluent or not?
it is fluent
is broca’s speech sensible/appropriate to the question?
yes
is wernicke’s speech sensible/appropriate to the question?
no
people wernicke’s aphasia can not do what?
understand speech
people with broca’s aphasia can not do what?
express speech fluently
