Stroke Flashcards
What parts of a history make an event sound like a stroke?
Rapid development of symptoms
Focal => certain part of brain is affected and is causing symptoms in specific places (not generalised)
Loss of brain function (e.g. pain is a positive symptom therefore not a sign of lost brain function)
What 3 thing should you establish when a patient presents to you with a suspected stroke?
– Time of onset?
– What were/are the symptoms?
– How did they progress?
What fraction of stroke presentations are made up by mimic presentations of a stroke?
1/3
What can cause a mimic of a stroke presentation?
- Seizure (weakness down one side can occur here)
- SEPSIS
- Toxic/ metabolic causes (=> check blood glucose)
- Space occupying lesions in brain can bleed and cause stroke mimic
What is the ROSIER score?
“Recognition of Stroke in the Emergency Room” Score
Checklist of symptoms/signs experienced by patient
A score of >0 indicates probable stroke
What are the 3 main types of stroke?
Infarct (85%)
Haemorrhagic (10%)
Sub-arachnoid Haemorrhage
What are the different causes of Haemorrhagic stroke?
- Structural abnormality in brain
- Hypertensive
- Amyloid deposition (makes blood vessels fragile & bleed)
What are the different subtypes of infarct stroke?
Athero-embolic => plaques in aorta create emboli which travel upwards
Small vessel => clots form in small vessels of brain due to normal cardio risk factors (BP and cholesterol)
Cardio-embolic => AF creates clots which travel upwards
Clinically we are able to tell the difference between haemorrhagic and infarct strokes. TRUE/FALSE?
FALSE
Imaging used to work this out
What type of scans are used on admission with a suspected stroke?
CT head
MRI
Why is CT a useful scan to complete first?
- Quick to complete
- Usually machines available readily in acute need
- Good at picking up blood (white) in haemorrhagic stroke
- can show if blood is occupying significant amount of space in the brain
What can be interpreted on a CT head showing an infarct stroke?
- non-symmetrical brain (dark patch often seen)
- dark patch resembles oedema produced from necrotic tissue
An infarct stroke may not always be seen on imaging. TRUE/FALSE?
TRUE
If imaging is taken very soon after stroke is suspected then no oedema may have formed as the brain tissue is not yet dead
clots in cerebral arteries can sometimes be visualised which show a risk of stroke
What strokes are poorly imaged by CT?
Posterior strokes
- bone gets in the way of the radiation
How do MRIs look for abnormalities in the brain?
They use diffusion-weighted technology
=> look for abnormalities in the diffusion of fluid and ions in the brain
- 2 different types of image are compared and look for a corresponding abnormal patch to diagnose a stroke