Ischaemic stroke (summary)
Updates to Article Attributes
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Stroke is a clinical diagnosis where an acute neurological deficit follows a cerebrovascular insult. There are two main groups of stroke: ischaemic (>80%) or haemorrhagic (<20%) 1.
Reference article
This is a summary article; read more in our article on stroke.
Summary
- anatomy
-
epidemiology
- common
- leading cause of disability
- third highest cause of mortality in the UK 2,3
-
presentation
- sudden neurological deficit
- manifest symptoms depend on the vascular territories involved
- time of onset is important when considering treatment
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pathophysiology
- brain parenchyma is deprived of blood flow and therefore oxygen
- ischaemic
- arteries occluded by thrombus or embolus
- temporary loss of blood flow may occur (TIA)
- cell death results in oedema and swelling
-
investigation
- non-contrast CT head in the first instance
- exclude haemorrhage or other cause
- may show hyperdense vessel or evidence of infarction
- CT angiography
- some centres use this to identify blockages and assess collaterals when planning clot retrieval
- MRI
- less commonly used for acute events, but good for identifying infarcts (especially using DWI sequences)
- ultrasound
- carotid Doppler ultrasound in the peri-stroke period to select patients who may benefit from endarterectomy
- non-contrast CT head in the first instance
-
treatment
- thrombolysis or thrombectomy
- ischaemic strokes less than 4.5 hours old
- depends on the local protocol
- should be discussed with an acute stroke service
- stroke patients should be managed in a stroke centre
- oral antiplatelet therapy
- medical management of hypertension and risk factor reduction
- thrombolysis or thrombectomy
Imaging
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role of imaging
- is there evidence of stroke?
- what is the distribution and severity of the stroke?
- is there haemorrhagic transformation?
- is a cause visible, e.g. in situ thrombus?
- are there contraindications to IV thrombolysis?
- are there indications for clot-retrieval?
- is there significant carotid stenosis?
-
radiographic features
- CT
- parenchymal infarction may not be visible in the acute setting
- with time, cytotoxic oedema causes reduced density on CT
- clot within a vessel may be seen as hyperdensity
- acute haemorrhage will appear dense
- MRI
- the most important sequence is the DWI (diffusion sequence)
- diffusion restriction in this context is highly sensitive for ischaemia
- angiography (CTA/MRA/DSA)
- assessment of arterial supply to confirm whether a clot is present
- perfusion (CT/MRI)
- assessment of ischaemic/infarcted areas
-
ischaemicischaemia may be reversible
- carotid doppler
- not
usedin the acute setting but usually within two weeks following onset - assessment of the neck vessels looking for carotid stenosis
- if >70% stenosis on affected side, surgery may be offered
- not
- CT
- +<li>oral antiplatelet therapy</li>
-<li>ischaemic may be reversible</li>- +<li>ischaemia may be reversible</li>
-<li>not used in the acute setting</li>- +<li>not in the acute setting but usually within two weeks following onset</li>
- +<li>if >70% stenosis on affected side, surgery may be offered</li>
Images Changes:
Image ( update )
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Case 2: Hyperdense collection in left basal ganglia with extension into ventricular systemhaemorrhage, likely hypertensive
Image 6 CT (non-contrast) ( update )
![](https://prod-images-static.radiopaedia.org/images/10913397/42bec780a99f33acbe8d6c1390e17d_thumb.jpg)
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Case 3: Hypodensityhypodensity in left PCA territory (ischaemic stroke)
Image 7 CT (non-contrast) ( update )
![](https://prod-images-static.radiopaedia.org/images/10883436/b6075c359aca4c69c45ab6056ebe61_thumb.jpg)
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Case 4: Hyperdensehyperdense right MCA
Image 8 CT (non-contrast) ( update )
![](https://prod-images-static.radiopaedia.org/images/10883547/8db5c9869c07d97d12a1e50755a470_thumb.jpg)
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Case 4: Hypodensity infollow up, infarcted right MCA territory