2) Disorders of CNS, circulatory diseases Flashcards Preview

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Flashcards in 2) Disorders of CNS, circulatory diseases Deck (10):

What are the three types of strokes?

Ischaemic stroke
subarachnoid haemorrhage
intracerebral haemorrhage


What is a stroke?

The sudden death of brain cells due to lack of oxygen, caused by blockage of an artery or the rupture of an artery


Cerebral ischaemia (define, types, most common cause?)

- A term describing an acute episode of neurologic deficit
- Not enough blood flow to the brain to meet metabolic demand due to blockage of an artery (usually MCA). This causes death of brain tissue. Types:
--> Thrombotic: Blood clot forms within the brain
--> Embolic: Blood clot forms elsewhere in the body and travels to brain via bloodstream before becoming lodged in the brain
--> lacunar: occlusion of small vessels
-can be acute (1 day to 1 week), subacute (1 week to 1 month), or chronic (> 1 month)
- Atherosclerotic disease is most common cause


Subarachnoid haemorrhage (define, how is it different to intracerebral haemorrhage)

- When a vessel just outside the brain ruptures, rapidly filling subarachnoid space


Intracerebral haemorrhage (define, how is it different to subarachnoid haemorrhage)

- Occurs when a diseased vessel within the brain bursts



A disease in which plaque builds up inside your arteries, causing them to narrow



trans-ischemic attacks are focal neurologic deficits that resolve in less than 24hrs. Partial blockage of an artery, temporary decrease of blood supply


Radiological features of cerebral ischaemia
CT (___, early___ signs, late signs)
MRI (better for___, early signs, ____)
Angio (Accurate___)

- Dense artery sign (MCA) due to fresh thrombus occluding a vessel
- Early parenchymal signs: reduced grey matter density --> brain swelling
- Late signs: Atrophy with adjacent sulci & ventricle enlargement

- better for showing extent of ischaemic change and is more sensitive for early infarcts
- Early signs: reduced perfusion when the parenchyma still appears normal
- haemorrhagic transformation follows secondary bleeding into areas of reperfused tissue

- accurate tandem lesion evaluation, where stenosis is close to 50% and not sure whether to treat medically or surgically


Subarachnoid haemorrhage radiological features (CT, MRI)

CT: non-con shows high attenuation of blood in subarachnoid space

MRI: Best demonstrates chronic haemorrhages as hypointense areas on T2


Intraparenchymal/intracerebral haemorrhage radiological features (CT)

CT: New haematoma appears homogenously dense, well defined, round or oval lesion, becoming isodense overtime. 6 month old lesion appears as well defined isodense lesion