Stroke presentation Flashcards
What is a stroke
Damage to part of the brain due to a blockage of a blood vessel by thrombus/embolus OR due to haemorrhage due to rupture of a blood vessel
What is the difference between a stroke and a transient ischaemic attack
Stroke - loss of function for >24hrs
TIC - loss of function for <24hrs
What is a trans ischaemic attack also sometimes called
Mini stroke
Warning stroke
What causes a stroke
Blockage of a vessel
Disease of a vessel wall
Change in blood properties
Rupture of vessel wall
What is virchows triad
Blood properties
Blood flow
Wall change
What percentage of strokes are caused by infarction/ishaemic
85%
What percentage of strokes are due to a rupture of a blood vessel ie Haemorrhagic
15%
In what ways can a vessel be blocked in a ischaemic stroke? (x5)
Carotid stenosis (35%) Cardioembolic stroke (25%) Lacunar stroke (25%) Undetermined (10-15%) Arterial dissection/trauma (<5%)
How does carotid stenosis cause stroke
Atheroma is more common at the bifurcations due to increased turbulent flow. It builds up and blocks the blood travelling through the vessel.
What is a cardio-embolic stroke
Heart pumps unwanted materials up to the brain. Stagnant coagulated blood from atrial fibrillation is a common cause.
What is a Lacunar stroke
Clot in the little penetrating arteries in the brain. It usually in the white matter so is a result of disease
What are causes of haemorrhagic stroke
Primary intracerebral haemorrhage (70%) Secondary haemorrhage (30%)
What do the symptoms of a stroke entirely depend on?
What area of the brain is affected
What artery is blocked
What does a ischeaemic stroke look like on a CT
A black, darkened area
What does a haemorrhaging stroke look like on a CT
A white area (liquid)
What part of the brain gets affected if internal carotid artery is occluded
Anterior
Hemispheres
Cortical deep white matter
What part of the brain gets affected if the vertebral artery is occluded
Posterior
Vertebrobasular territory
Occipital
What is the Vertebrobasular territory
Brain stem Pons Cerebellum Midbrain medulla
What is typical of a left sided stroke
Carotid blocked
Cerebral hemispheres affected
Cortex (cortical stroke)
What is typical of a right sided stroke
Vertebrobasular territory affected
Brain stem affected
Deep white matter affected (lacunar)
What allows the approximate location of a stroke to be determined
The symptoms
Why is it important to approximate the location of a stroke before carrying out further investigation
Allows for
better selection of imaging,
an indication of cause,
helps estimate prognosis
What are the subtypes that stroke can be classified into after stroke has been identified (x4)
Total Anterior circulation stroke (TACS)
Partial anterior circulation stroke (PACS)
Lacunar stroke (LACS)
Posterior circulation stroke (POCS)
What is a Total Anterior circulation stroke (TACS) and what does it cause
occlusion of middle cerebral or internal carotid artery
causes:
Weakness
Loss of vision
higher cerebral dysfunction
What is a Partial anterior circulation stroke (PACS)
Occlusion of branches of middle cerebral artery
Diagnosed if patient only has 2/3 of the criteria for a TACS
What is a Lacunar stroke (LACS) and what does it cause
Occlusion of the smaller branching arteries
Pure motor - Complete of incomplete weakness of 1 side involving 2/3 of arm face or leg
Pure sensory - Sensory symptoms and/or signs, same distribution
These are often silent and undiagnosed.
What is a Posterior circulation stroke (POCS)
A stroke that affects the brainstem. cerebellar or occipital lobes
It has a complex presentation
bilateral motor/sensory deficit disordered conjugate eye movement isolated homonymous hemianopia ipsilateral cranial nerve palsy with contralateral motor/sensory deficit coma disordered breathing tinnitus vertigo Horner’s
What are modifiable stroke risk factors
Blood pressure and atrial fibrillation
What are non-modifiable stroke risk factors
Age
Race
Family history
What sub type of stroke has the highest mortality
TACS
