CLINICAL- STROKE Flashcards
What’s a cerebral infarct?
A type of stroke resulting from blockage in one of the blood vessels supplying blood to the brain. The blood supply to that part is lost resulting in death of the area.
It is different from cerebral hemorrhage or subarachnoid hemorrhage.
What is a cerebral heamorrhage?
Spontaneous bleeding into the brain tissue
Second most common cause of stroke
It’s NOT caused by a clot (so don’t use alteplase!)
What is a subarachnoid heamorrhage?
Bleeding into the subarachnoid space (outside of the brain, inside the skull)
Can be a cause of stroke
Can occur spontaneously or from head injury
What is the difference between ischemic stroke and hemorrhagic stroke? Which is most common?
Ischemic stroke occurs because if an obstruction in a blood vessel (e.g: cerebral infarct: clot in the brain blood vessels).
This is the most common kind of stroke
Heamorrhagic stroke occurs when a weak blood vessel ruptures. It can be a cerebral heamorrhage or a subarachnoid heamorrhage.
Causes of ischaemic stroke can be embolic or thrombotic. What are these?
Embolic is where the clot has come from elsewhere in the body and has broken off and blocked a vessel.
Thrombotic is where the blood vessel walls get narrower and narrower due to plaque formation/ atherosclerosis
Where are common locations for plaques/ thrombotic blockages to form??
Anywhere the blood vessels branch off.
Branches coming together
The circle of Willis: blood vessels that compensate for any narrowing or blockages in the the main blood vessels, blood can bypass the narrow vessel
When someone comes in with symptoms of stroke, we need to find out whether it’s a haemorrhagic stroke or an ischemic stroke so that we know whether we can give thrombolysis/ clot buster. How do we distinguish?
Do a CT scan
If someone’s had bleeding on the brain you can tell within 30seconds with a CT scan
Alteplase is the fibrinolytic drug of choice (clot buster) used in stroke. When is it not indicated?
After 4.5 hours from the onset of symptoms
Stoke is the 3rd most common cause of death after heart disease and cancer
Stroke is the most common cause of severe disability
After the acute treatment after a stroke has occurred, secondary prevention and rehabilitation (if needed) are started.
Rehabilitation helps with stroke related disability
In the primary prevention of stroke, what’s the mass population strategy??
Blood pressure
Smoking
Lipids (cholesterol)
In the primary prevention of stroke, what risks, part from the mass population ones (hypertension, smoking and cholesterol), are managed in the high risk strategy??
Diabetes
Atrial fibrillation
Other vascular diseases (e.g. Congestive cardiac failure, Myocardial infarction, carotid artery stenosis)
Previous TIA
What is a big risk factor for stroke in young men?
Binge drinking at the weekends
What risk factor contributes the most risk of stroke??
Hypertension!!
If you can get the diastolic BP to drop by just 7.5 mmHg, you’re looking at a 46% reduction in their likelihood of stroke
What can we give to patients with AF to reduce their likelihood of stroke by 60-80%??
Warfarin
Is stroke more common in men or women?
Men
The prevalence of stroke is increasing because….
People are living longer and longer, and stroke likelihood increases with age!!
What is a TIA?
Trans ischeamic attack It has a sudden onset- no warning signs Short lived Full recovery by one hour May have a single one or multiple over time
Mini stroke
Patients who have had a TIA are more at risk of a stroke because it indicates there was a temporary disruption in the blood supply to the brain so there must be something going on
(Like an earthquake leading to a volcanoe)
What could TIA be mistaken for??
Partial epileptic seizure Migraine with aura A Hypo Drunk/ on drugs! Hysteria
CT scan can be used to distinguish a TIA from cerebral heamorrhage, brain infection or injury but doesn’t help to exclude the possibilities above!!
In practice it is most important to distinguish between haemorrhage and ischeamic stroke, as their treatment is so different but their symptoms overlap
What is the Allen score used for?
Found to be 90% accurate in the identification of heamorrhage
Which type of stroke has HRT (hormone replacement therapy) not been associated as increasing the risk of?
Haemorrhagic stroke
It has been associated with total stroke, non fatal stroke, fatal stroke and ischeamic stroke
When should TIA patients get taken to hospital?
If symptoms are ongoing and have come on within the last 180 minutes they should go to hospital in an ambulance.
Patients that arrive within 180 mins (3 hours) of symptom onset should undergo examination as to whether they need thrombolysis.
If high risk- admit an thrombolysis
If low risk- TIA clinic
What scoring system is used to assess the risk of stroke after a TIA?
ABCD2 score
Age BP Clinical features Duration of symptoms Diabetes history
(See book)
What ABCD2 score classifies as high risk of stroke after TIA?
Score of 4 and above
Need to refer for specialist assessment within 24 hours!!
What does an ABCD2 score of 3 or below indicate??
Low risk of stroke after TIA
Refer for specialist assessment within 7 DAYS
In the ABCD2 scoring system what does symptoms lasting for under 10 minutes score?
Zero!
10-59 minutes scores 1
Over 60 minutes scores 2
The longer the symptoms last, the more likely you’ll have to go for specialist assessment more urgently!!
What does unilateral weakness score on the ABCD2 scoring system for TIA severity?
2
Speech disturbance without weakness scores 1
Fall under clinical features
What should patients with TIA immediately receive??
Anti platelet therapy: Aspirin 300mg STAT
(Allergic to aspirin or not tolerated with a PPI added go for clopidogrel 75mg OD but this is unlicensed!)
This is all in BNF under transient ischeamic attack in stroke section!!
How should aspirin and clopidogrel be prescribed following a STROKE?
Aspirin 300mg for 14 days
Then clopidogrel 75mg OD thereafter
We may be on this combo for CV disease as well! (Dual antiplatelet therapy post STEMI!) these patients: need dual therapy for 12 months after event, then usually just on aspirin, but in stroke patients maintain them on clopidogrel forever instead
What’s the difference in aspirin prescribed for TIA and for stroke?
TIA: it’s just a 300mg STAT dose (one day) then 75mg clopidogrel forever after
Stroke: 300mg aspirin OD for 14 days, then 75mg clopidogrel forever after
What’s the deal with blood pressure control in patients who have had a stroke or TIA?
They should be on BP medication unless their BP is really low.
Even if they are nomotensive, it would still be beneficial to lower their BP.
Statins reduce the risk of stroke occurring after TIA/ after a stroke.
What cholesterol level should we definitely consider Statin therapy for?
Over 5.2 mmol/L
How long after the acute phase of stroke should we wait until we start messing around with patients medication e.g. Introducing a Statin, increasing BP medication..?
Wait for 48 hours!
What is carotid artery stenosis??
Narrowing of the carotid artery (usually by atherosclerosis).
This is the large artery on either side of the neck
It bifurcates (splits in two) and this bifurcation is a common place for atherosclerosis to build up.
If it becomes completely blocked there is still the circle of Willis to compensate
Carotid artery stenosis can either present with no symptoms or with symptoms such as TIA’s or strokes
What is a carotid endarterectomy?
Carotid stenosis can occur where the carotid artery becomes narrow.
A carotid endarterectomy is a surgical procedure used to reduce the risk of stroke, by correcting the narrowing stenosis of the carotid artery by removing material from it: scraping it out!!! Or actually pulling the clot out of it…
The plaques that have built up in this artery can cause TIAs. Symptomatic stenosis has a high risk of stroke within the next two days
Are patients with a symptomatic carotid stenosis or unsymptomatic carotid stenosis more at risk of stroke??
Symptomatic
But unsymptomatic still at a higher risk than the general population
What is carotid stenting??
A stent, which is a mesh like tube, is inserted into the carotid artery to stop them getting any narrower or the plaque breaking down and causing blockage and a stroke
Patients with a ABCD2 score of __ or more with symptomatic _______ _____ can undergo brain imaging of their _____ artery after a TIA in order to determine whether they would benefit from ________ endarterectomy / a stent
4 or more
Symptomatic Carotid stenosis
Carotid artery
Carotid endarterectomy
How much more likely are you to have a stroke if you have AF?
5 times more likely
Incidence of AF rises rapidly with old age
Stroke incidence in AF also increased with age