lecture 18 - stroke Flashcards
What are the general risk factors for all types pf stroke?
hypertension, hyperlipidaemia, increasing age, smoking, alcohol abuse, physical inactivity, obesity, stress, diabetes
What is a transient ischaemic attack?
An acute attack of temporary focal neurological dysfunction caused by a vascular event without infarction.
What are the key types of stroke?
Ischaemic (80%), haemorrhagic (20%)
What are the 2 key sub-types of haemorrhagic stroke?
Hypertensive intracerebral bleeding, subarachnoid haemorrhage
How does a haemorrhagic stroke cause neuronal injury?
There is a rapid increase in pressure resultiung in swelling and raised ICP and a reduction in perfusion. Blood triggers vasospasm which causes further ischaemia.
What are the focal features of a haemorrhagic stroke?
These are specific to the damaged area, and may include weakness, sensory loss, visual field defects, etc. Will often be unilateral
What are non-localised features of a haemorrhagic stroke?
Signs of raised ICP: headache, nausea, vomiting, confusion, coma
What are the 2 key subtypes of ischaemic strokes?
Global cerebral ischaemia, focal ischaemia
What are the 2 types of focal ischemic stroke?
Emobilic, Thrombotic
What is the pathophysiology of hypertensive cerebrovascular disease and stroke?
hypertension causes hyaline arteriosclerosis in deep penetrating arteries of the basal ganglia, hemispheric white matter and brain stem. It also causes atherosclerosis in cerebral arteries. When large vessels rupture it causes intraparenchymal haemorrhage and when small penetrating vessels rupture it results in slit haemorrhages/lacunar infarts
Where in the brain does hypertensive intracerebral haemorrhage usually occur?
Centrally - basal ganglia, thalamus, pons
What is the most common cause of a subarachnoid haemorrhage?
Rupture of a berry aneurysm in the Circle OF Willis
What is the penumbra in a stroke?
An area lying around an ischaemic region of tissue that has potentially reversible damage if circulation is restored
What type of infarct is associated with an emoblic stroke?
Haemorrhagic
What are common causes of an embolic stroke?
emboli formed from MI, AF, valvular heart disease, thrombosis of atherosclerotic plaques, DVT passing through PFO
What is the gross appearance of an embolic stroke?
Area of haemorrhagic ischaemia with multiple petechial haemorrhages and an area of redness