Stroke - College lecture series Flashcards
College lecture series
What is the incidence of CVA within the general population?
One in Four
Number 2 cause of death worldwide!
Number 1 cause of disability in adults!
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What Stroke syndrome is being described?
” RIGHT sided hemiparesis of face/arm > Leg + Sensory/visual innatention + LEFT heminaopia “
LEFT MCA syndrome
In a Left MCA stroke you USUALLY get Aphasia
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What Stroke syndrome is being described?
” LEFT sided hemiparesis of face/arm > Leg + Sensory/visual innatention + RIGHT heminaopia “
RIGHT MCA syndrome
In a right MCA stroke you usually get a “dysarthria” rather than aphasia
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What Stroke syndrome is being described:
- Isolated face / arm / leg weakness that is equal in all zones
- isolated face / arm / leg sensory loss that is equal in all zones
- ataxic hemiperisis
- (can be a mixture of sensory and motor)
LACUNAR syndrome
absence of CORTICAL signs (innatention, aphasia, hemianopia)
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What Stroke Syndrome is being described:
- Diplopia
- vertigo
- dysarthria
- dysphagia
- ataxia
- Hemi/tetraperesis
- IPSIlateral face / CONTRAlateral body numb/weakness
POSTERIOR CIRCULATION syndrome
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What is this CVA’s underlying pathology?
Anterior communicating Artery bleed
Here you see blood in the base of the skull anteriorly
be suspicious of an anterior communicating aneurysm bleed!
ORDER a CTAngiogram
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What is this CVA’s underlying pathology?
Here blood is located around the sylvian fissure
be suspicious of a MCA aneurysm
ORDER a CTAngiogram
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What is this CVA’s underlying pathology?
Venous Sinus Thrombosis
Here there is a hyperdense sign near the venous sinus area
order a CT Venogram
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What is the term used to classify this sign on imaging?
HYPERDENSE SIGN
Seen when there is an occlusion in an artery - here the Left MCA
you see these better in 1mm slices (so make sure you have the right window)
90% sensitive for an ACUTE thrombus - Reidal et al Stroke 2012
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How would you describe this sign on imaging?
Here you see loss of grey white differentiation
- an established stroke ( > 4.5Hrs)
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What is the estimated % threshold for cerebral blod flow used in CT perfusion to determine an area of core infarct?
Less than 30%
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What is the threshold in seconds used in CT perfusion imaging to determine an area ‘At risk’ of irreversible injury?
More than 6 seconds
you combine this with area of cerebral blood flow of < 30% to determine CORE INFARCT
Then calculate the mismatch and whether its worth reperfusing.
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What is this sign called on CTa?
(indicated by the arrow)
SPOT sign
There is active bleeding here as there is contrast extravasation
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What is the underlying pathophysiological process seen on Diffusion weighted imaging MRI in stroke patients?
You get cytotoxic oedema
as water rushes into the infarcted cells
which has LESS motion on MRI therefore RESTRICTED DIFFUSION(bouncing around)
Note: also seen in MS plaques and dense tumours (Glioblastomas.)
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A patient who is a surgical canditate presents with an ischeamic CVA (after 48 hours) due to a carotid stenosis of > 50%
The initial antiplatelet plan has been instigated
what is the next best step?
1) Yearly surveillance with a Carotid US
2) vascular review for ? Endarterectomy
Endarterectomy
The general rule is:
If symptomatic (TIA / CVA) and known stenosis (of > 50%) - should be considered for surgery
the risk of a repeated stroke is highest in the 2 weeks following an event
if > 70% (AFP says 80%) - then surgery should be considered regardless
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A patient has been managed for a hemorrhagic stroke
At what time interval do you perform a follow up MRI post discharge?
8 Weeks
To look for mass lesions, cavernomas, AVMs, microangiopathy,
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How does Alteplase / Tenecteplase work?
Converts Plasminogen to Plasmin (which breaks down the clot)
What is the time window for use of ANECTEPLASE/TENECTEPLASE ?
Up to 4.5 hours in ALL (eligible) patients
or
up to 9 Hours in WUS patients / those still favourible on CT perfusion - *EXTEND 2019 meta analysis *
Which of these is a contraindication to TPa?
- Recent GI/UGI bleeding / surgery / trauma
- Bp < 185/105
- BSL of 4 mmol
- infective endocarditis
contraindications to TPa:
- Haemorhhage on CTP
- Extensive hypdensity? (check the onset time again)
- active non compresible systemic bleeding
- Recent GI/UGI bleeding / surgery / trauma = Risk Vs Benefit > ? Thrombectomy
- Bp > 185/105
- BSL < 2.7mmol (need to fix this and reexamine need)
- infective endocarditis
- Aortic dissection
- Malignant brain tumours
- INR > 1.7
- platelets < 100
- DOAC < 48 hours - Dabigatran (reversible with idracuzimab) - this guideline might change soon
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What is this a sign of (post TPa administration)
Orolingual angiooedema post tPA
- swelling around lips and tongue
- 2% of patients (5% if on Acei)
- usually CONTRALATERAL to brain lesion
- 15 - 105mins post tPA bolus
- DDX: Tongue hematoma
- Hydrocortisone / antihistamine
- ICATIBANT? - as thought to be bradykinin mediated
- usually does not need airway support
What receptor does Clopidogrel act on?
PY12 receptor agonist
Approximately what % of Asians are resistant to clopidogrel
**20% **
as it is activated in the liver
20% of asians are thought to have a defect in the **CYP2C19 Allele **
What investigation would you order to investigate someone with a potential PFO?
BUBBLE TTE - note patient has to be able to Valsalva (TOE is an alternative)
the ‘MR CLEAN’ Trial was a study thatsignificantly contributed to the “time is brain” concept, emphasizing the importance of fast and efficient stroke treatment.
How long following the onset of sx (in hours) did it show a benefit for thrombectomy, in CTa selected patients?
A - 4 hours
B - 6 hours
C - 8 hours
D - 12 Hours
B - 6 HOURS
