Acute stroke Flashcards
What percentage of total blood volume circulates through the brain, and at what rate?
20% of total blood volume at approximately 750mL/minute.
What is the definition of ischaemic stroke?
An episode of neurological dysfunction caused by focal cerebral, spinal, or retinal infarction.
What is the definition of stroke caused by intracerebral haemorrhage?
Rapidy developing clinical signs of neurological dysfunction attributable to a focal collection of blood within the brain parenchyma or ventricular system that is not caused by trauma
What is the definition of stroke caused by subarachnoid haemorrhage?
Rapidly developing signs of neurological dysfunction and/or headache because of bleeding into the subarachnoid space (space between the arachnoid membrance and the pia mater of the brain or spinal cord) which is not caused by trauma
What is the definition of stroke, not otherwise specified?
An episode of acute neurological dysfunction presumed to be caused by ischemia or haemorrhage, persisting 24 hours or more or until death, but without sufficient evidence to be classified as one of the above.
What is a transient ischaemic attack?
A neurological deficit that resolves, usually within 24 hours
How many TIAs progress to stroke?
One third
What percentage of strokes can be prevented?
More than 80%
Approximately ____% of acute strokes are ischaemic
80%
Approximately ____% of acute strokes are haemorrhagic
20%
Approximately 20% of ischaemic strokes are clots travelling from the ____.
Heart
Where does thrombus formation typically occur?
Origin or bifurcation of arteries
What are the causes of embolism?
- Vascular stasis (stenotic vessels, AF, MI, un-ruptured aneurysms)
- Thromboembolism
- Gas embolism
- Amniotic fluid embolism
- Fat embolism
What are the thrombotic risk factors?
- Hypertension
- Hyperlipidaemia
- Diabetes
- Smoking
- Obesity
- Systemic atherosclerosis
- Hypercoagulable states
What are the embolic risk factors?
- AF
- Endocarditis
- Dilated cardiomyopathy
- Recent MI
- Heart valve replacement
- Rheumatic heart disease
- Patent foramen ovale