1(E) - Cerebrovascular Accident Flashcards
Define stroke
Interruption in vascular supply to the brain
What are the two main types of stroke
Ischaemic
Haemorrhagic
What is ischaemic stroke
Occlusion of blood vessel
What % of strokes are ischaemia
85%
What are two types of ischaemic stroke
- Thrombotic
- Embolic
What is a thrombus
Narrowing of vessel due to atherosclerosis
What is an embolic stroke
Blood Clot, Air , Fat or bacteria that travel and occlude an artery
What is haemorrhage stroke
Rupture blood-vessel causing reduction in blood flow
What % of strokes are haemorrhage
15%
What are the two types of haemorrhagic stroke
- Intracerebral (10%)
- SAH (5%)
What is the new definition of TIA
- transient episode neurological dysfunction caused by ischaemia to cerebral cortex, spinal cord or retina
What was the old definition of TIA
- Transient neurological dysfunction lasting less than 24-hours
What is difference between TIA and Ischaemic Stroke
TIA = ischaemia Stroke = infarction
What are modifiable risk-factors for TIA
- Smoke
- Obesity
- Alcohol
- High-Lipids
- CVD
- DM
- COCP
- HRT
- HTN
What are 5 non-modifiable risk factors for TIA
- Male
- Over 65-years
- African American
- FH
- migraine with aura
What is amaurosis fugax
Occlusion retinal or ophthalmic artery
If an individual had a TIA in past 7-days, how quickly should they be referred to specialist
24 hours
If an individual had a TIA more than one week ago, how soon should they be seen by a stroke specialist
7 days
What is given to manage TIA in short-term
Aspirin (300mg)
What imaging is ordered same-day in TIA and why
MRI
What is given as secondary prevention in TIA
Clopidogrel
What imaging do all patients with TIA received
Carotid Artery US
If carotid stenosis is present, what imaging is used
CTA
What are indications for carotid endarterectomy
More than 70%
Symptomatic and 50-99% Occluded
What are individuals with TIA at highest risk of and when is this most common
Ischaemic stroke - more common in first few days following TIA
What scoring system was used to predict individuals with TIA risk of developing ischaemic stroke
ABCD2
What is an ischaemic stroke
Occlusion cerebral blood vessel causing tissue infarction
Wha % of strokes are ischaemic
85
What is the main cause of ischaemic strokes
Thrombus
What are other causes for ischaemic stroke
Embolus
Global cerebral hypo perfusion
Hyper coagulable state
What causes thrombotic stroke
Atherosclerosis of cerebral blood vessels
Where are thromboses most likely to form
Branching-points
Which artery to embolic strokes most commonly affected
MCA
What causes embolic strokes
Clots from atrium
What causes a paradoxical embolus
Patent foramen ovale - enables thrombus from DVT to pass to cause stroke
What causes global cerebral hypo perfusion
- Bilateral carotid artery stenosis
- Global hypoperfusion
What other causes of stroke
- Polycythaemia
- Thrombophilia
- COCP
- HRT
- Sickle Cell
- Vasculitis
- Arterial Dissection
What are 3 risk factors for embolic ischaemic stroke
AF
Endocarditis
Patent FO
What are modifiable risk factors for ischaemic thrombotic stroke
Cardiovascular RF: Smoking, HTN, Alcohol. DM, PVD, CAD,. COCP
What are non modifiable risk factors for thrombotic ischaemic stroke
Male
Age
FH
How does occlusion ACA present clinically
Hemiplegia (usually) of the leg and hemiparesis (weakness) of the arm
How will MCA occlusion present
- Hemiparesis of face (forehead sparing) and arm
- Contralateral homonymous hemianopia
- Expressive and receptive aphasia (Brocca’s and Wernicke’s)
- If non-dominant = semi-spatial neglect
Where does the ophthalmic artery originate
Internal carotid artery
What causes amaurosis fugax
Clot in opthalmic which passes to occlude central retinal artery
If a patient with a stroke has hemianopia, what vessels must be affected
PCA or MCA
How do PCA strokes present
Homonymous hemianopia with macula sparing. May not present acutely but can present to opticians with history bumping into things
Why does MCA cause homonymous hemianopia
Due to ischaemia Meyer’s loop and Baum’s loop
Where is broccas areas
Pars opercularis, Pars triangularis
Where is Wernicke’s area
Superior temporal gyrus
What do the vertebrobasilar arteries supply
Occipital Lobe
Cerebellum
Brain Stem