Neuro Flashcards
Proportion of the strokes by type
80% ischaemic
15% intra-parenchymal bleeds
5% SAH
Causes of vessel blockage
Atherothromboembolism (50%)
Vessel disease (25%)
Cardiac source of embolism (20%)
Rare causes (5%)
SAH - on CT where is the blood
fill the cisterns
may be intra-parenchymal
stroke rule of thirds
third die
third left dependant
third will survive
Differentials to consider for stroke
Epilepsy Tumour Abscess Hypoglycaemia Encephalitis Other sepsis Syncope, etc.
What information is required for clinical management?
Is the lesion vascular or non-vascular?
If vascular, is it an infarct or a haemorrhage?
Is there an underlying structural cause?
How extensive is the infarct?
If more than a third of the middle cerebral artery (MCA) territory is affected at presentation, then there is a high risk of haemorrhage with thrombolysis
Are there any features to suggest large vessel occlusion?
Questions regarding ischaemic penumbra and salvageable tissue are assessed by CT perfusion, which is not routinely performed
if something is dense (white) and has mass effect on CT it is
Haemorrhage
underlying lesion like a tumour or vascular malformation, then there may be some features to suggest that
underlying lesion like a tumour or vascular malformation, then there may be some features to suggest that
causes of haemorrhage
trauma, haemorrhagic transformation of an arterial or venous infarct, or to amyloid angiopathy
Low density after stroke (haemorrhage)
old
High density after stroke
new
Rate of change in density varies with size of lesion
smaller bleeds get removed quicker.
small will be hypodense at 7 days
large may take 12 weeks.
Slit like appearance of CSF fluid raises consideration for
ex vacuo from an old haemorrhage.
infarct would be more rounded
slits are more for the basal ganglia or centrum semiovale
Why is MR so good at measuring wether haemorrhage has taken place?
due to haemosiderin deposition which paramagnetic
However, it is not good for acute haemorrhage
Cortical infarcts
subtle as a small focal defect in the normal slightly hyperintense cortical ribbon
