Stroke Flashcards
Define stroke
Acute onset of focal neurological symptoms and signs Due to disruption of blood supply
What are the two types of stroke?
Haemorrhagic
Ischaemic
Describe haemorrhagic stroke?
-raised blood pressure
-weakened blood vessel wall due to
>structural abnormalities like aneurysm, arteriovenous malformation (AVM)
>inflammation of vessel wall (vasculitis)
Describe ischaemic stroke?
> thrombotic- clot blocking artery at the site of the occlusion
embolic- clot blocking artery has travelled to artery it occludes from somewhere more proximally in the arteries of the heart
hypo-perfusion- due to reduced flow of blood due to stenosed artery rather than the occlusion of the artery
What are the non-modifiable risk factors of stroke?
- age
- family history of any vascular disease
- gender (males)
- race (south Asians are higher risk)
- previous stroke
What are the potentially modifiable risk factors of stroke?
- hypertension
- hyperlipidaemia
- smoking
- prior history of TIA
- AF
- Diabetes
- CHF
- Alcohol excess
- obesity
- physical inactivity
- poor sociaoeconomic status
What are some rarer causes of stroke?
- homocysteinemia
- vasculitis, antiphospholipid antibody syndrome
- protein S, C, Antithrombin III deficiency
- paradoxical embolism
- Genetic
- Cardioembolic
- Cervical artery dissection
What is paradoxical embolism?
(venous clot to arterial side) through patent foramen ovale/pulmonary AV shunts (these are openings large enough between arterial and venous circulations)
Name some genetic factors?
Factor V Leiden mutation, common prothrombin mutation, MELAS, CADASIL, Fabry’s disease
What are some cardioembolic causes of stroke?
mural thrombi, infective endocarditis, myxoma
What are the behavioural adaptations for stroke prevention?
Diet
Exercise
Weight control
Smoking cessation
What is the window of opportunity after stroke?
up to 3-4 hours after symptoms started you could prevent the extent of the damage by opening up blocked artery
What is the treatment for stroke?
thrombolysis or thrombectomy
How do you prevent further stroke?
Discover origin, deal with it
What are some stroke mimics?
-hypoglycaemia
-seizure- postictal state
-migraine
-hyperglycaemia, hyponatremia
-space occupying lesions like brain tumours
>if they all of a sudden bleed into tumour
-functional hemiparesis
How do you determine which kind of stroke it is?
o brain scan
- CT/MRI
- angiogram
- DWI: sequence of MRI scan which is useful to look for ischaemic stroke
- SWI: sequence of MRI scan which is useful to look for old bleeds
If the patient is having an ischaemic stroke what is the protocol?
- find cause of embolism
- blood tests: glucose, lipids, thrombophilia (in young patients)
- assess for hypertension
- any other sign of blood vessel disease? coronary artery disease? PVD? maybe stroke is directly embolic from heart
What is atheroembolism?
embolism from a thrombus forming on a atherosclerotic plaque- platelet rich clots
Where does an atheroembolism infarct?
same side as affected carotid artery
What should be done if atheroembolism is suspected?
carotid scanning, CT/MR angiography of aortic arch
What is a cardioembolism?
embolism from a clot formed in the heart (usually left atrium)
What kind of clot is formed in cardioembolism?
clotting factor rich clots
Where does cardioembolism infarct?
More than one arterial artery
What investigations should be done if cardioembolism is suspected?
> ECG- ? AF? old ischaemic changes (mural thrombus)? LVH (suggests uncontrolled hypertension-commonest cause of AF)
> Echocardiogram (transthoracic, transoesophageal, bubble contrast study to look for interatrial connection)
> 24 hour- 5 day ECG monitor tests (Paroxysmal AF)
