Ischaemic stroke Flashcards
What is the essential problem in ischaemic strokes?
Blockage in the blood vessel stops the blood flow
What proportion of strokes are ischaemic strokes?
85% of strokes
What are the two main subtypes of ischaemic strokes?
- Thrombotic stroke
2. Embolic stroke
What is the definition of a thrombotic stroke?
Thrombosis from large vessels e.g. carotid
What is the definition of embolic stroke?
- a blood clot usually but fat/bacteria may act as an embolus
- Atrial fibrillation is an important cause of emboli forming in the heart
Name 5 general risk factors for ischaemic stroke
- Age
- Hypertension
- Smoking
- Hyperlipidaemia
- Diabetes mellitus
What is the definition of the Bamford classification?
( also known as the Oxford Stroke Classification )
- classifies ischaemic strokes based on the initial symptoms
What is the ‘Bamford classification’? (3)
- Unilateral hemiparesis and/or hemisensory loss of the face, arm or leg
- Homonymous hemianopia
- Cortical dysfunction e.g. Dysphasia
Name the features of a ‘Total anterior circulation stroke’?
(TACI) - involves middle and anterior cerebral arteries
1. Hemiparesis +/- hemisensory loss
(and)
2. Homonymous hemianopia
(and)
3. Cortical dysfunctionName the features of a ‘Partial anterior circulation stroke’ (PACI)
2/3 below
- Hemiparesis +/- hemisensory loss
- Homonymous hemianopia
- Cortical dysfunction
OR
- Cortical dysfunction alone
What does a ‘Lacunar stroke’ involve?
Involves perforating arteries around the internal capsule, thalamus and basal ganglia
What are the features of a ‘Lacunar stroke’?
- Hemiparesis - unilateral weakness of the body
(OR)
- Hemisensory loss - pure sensory stroke
(OR)
- Ataxic Hemiparesis
(no cortical dysfunction or hemianopia )
What do ‘Posterior circulation infarcts’ involve?
Involves vertebrobasilar arteries
How do POCI present?
Present with one of the following
1. Cerebellar or brainstem syndromes - diplopia / vertigo / ataxia
- Loss of consciousness
- Isolated homonymous hemianopia
Which subsect of ischaemic strokes have the worst prognosis?
Total anterior circulation stroke - mortality of 60% in a year
What is the ischaemic core?
Area of brain tissue local to the blood vessel occlusion whose blood supply is entirely supplied by this vessel, dies.
What is the ischaemic penumbra?
- Surrounding the ischaemic core is an area with some collateral blood supply.
- This salvageable tissue but without intervention is will also die
- Goal of hyperacute tx is to save this from becoming part of the ischaemic core.
