Cerebral Infarction Flashcards
How does stroke risk change with age?
Increases with age?
What is an example of public awareness being used to help treat stroke?
- Remember FAST
- Facial weakness
- Arm weakness
- Speech problems
- Time to call 999
What is a stroke?
Sudden onset of focal or global neurological symptoms caused by ischaemia or haemorrhage and lasting more than 24 hours
What are the 2 different broad categories of strokes?
Ischaemic stroke (85%)
Haemorrhagic stroke (15%)
Are most strokes ischaemic strokes or haemorrhagic strokes?
Ischaemic (85%)
What does TIA stand for?
Transient ischaemic attack
What is a transient ischaemic attack (TIA)?
Term used if symptoms resolve within 24 hours
How long do most TIAs take to resolve?
Most TIAs resolve within 1 to 60 minutes
What are the different causes of haemorrhagic stroke?
1) Primary intracerebral haemorrage
2) Secondary haemorrhage (subarachnoid haemorrhage or arteriovenous malformation)
What are the different causes of ischaemic stroke?
1) Large artery atherosclerosis (such as carotid)
2) Cardioembolic (such as atrial fibrillation)
3) Small artery occlusion
4) Undetermined/cryptogenic
5) Rare causes (arterial dissection, venous sinus thrombosis)
What are some modifiable risk factors for stroke?
- Smoking
- 2x increases risk of cerebral infarction
- 3x increased risk of subarachnoid haemorrhage
- Some of the increased risk relates to cardiac problems
- Obesity
- Independent risk factor for vascular disease including stroke
- AF
- 5x increased risk of embolic stroke
- Antiplatelets (such as aspirin) have no benefit in reducing ischaemic stroke
- Anticoagulants (warfarin and COACs) reduce risk by 2/3rds
- DOACs have less risk of causing bleeding than warfarin
- Cocaine
- Diabetes
- Diabetes increases incidence 3x
- Hyperlipidaemia
- Hypertension, smoke and diabetes contribute to LDL-C deposition in arterial walls
- Risk related to development of atheroma in blood vessel walls
- Hypertension
- Most important modifiable risk factor
- Chronic hypertension exacerbates atheroma and increases involvement of smaller distal arteries
- No exercise
- Diet
- Alcohol
- Small amounts may decrease stroke risk, heavy drinking increases risk 2.5x
- Oral contraceptives
What are some non-modifiable risk factors for stroke?
- Previous stroke
- Age
- Male
- Family history
What can reduce the risk of AF leading to a stroke?
- Anticoagulants (warfarin and DOACs) reduce risk by 2/3rds
- DOACs have less risk of causing bleeding than warfarin
How do small end arteries coming directly off large arteries have a higher risk of causing stroke?
Small end arteries coming directly off large arteries experience higher pressure and are at risk of lipohyalinosis (small vessel wall thickening, decreasing luminar diameter) causing:
- Lacunar ischaemic stroke
- Small vessel haemorrhages
What parts of the brain are at particular risk of lipohyalinosis?
- Brainstem
- Basal ganglia
- Subcortical areas
What is lipohyalinosis?
Small vessel wall thickening, decreasing luminar diameter
What can the circulation of the brain be seperated into?
Anterior circulation
Posterior circulation
What is the anterior circulation of the brain composed of?
What is the posterior circulation of the brain composed of?
What does the carotid system supply?
Most of the hesmispheres of the brain and cortical deep white matter
What does the vertebro-basilar system supply?
The brainstem, cerebellum and occipital lobes
Signs and symptoms of stroke should correlate to what?
Fit in with an artery territory and an area of the brain
Diagnosis of a stroke should give an answer to what questions?
- What is the neurological deficit
- Where is the lesion
- What is the lesion
- Why has the lesion occurred
- What are the potential complications and prognosis
What are some frontal lobe functions?
- High level cognitive functions
- Such as abstraction, concentration, reasoning
- Memory
- Control of voluntary eye movements
- Motor control of speech (dominant hemisphere)
- Motor cortex
- Urinary continence
- Emotion and personality
What are examples of high level cognitive functions?
- Such as abstraction, concentration, reasoning
What are some parietal lobe functions?
- Sensory cortex
- Sensation (identify modalities of touch, pressure, position)
- Awareness of parts of the body
- Spatial orientation and visuospatial information (non dominant hemisphere)
- Ability to perform learning motor tasks (dominant)
What cortex is found in the parietal lobe?
Sensory cortex
What are some temporal lobe functions?
- Primary auditory receptive area
- Comprehension of speech (dominant)
- Visual, auditory and olfactory perception
- Important role in learning, memory and emotional affect
What lobe is the primary auditory receptive area found?
Temporal lobe
In what lobe is the visual cortex found?
Occipital lobe
What are some occipital lobe functions?
- Primary visual cortex
- Visual perception
- Involuntary smooth eye movement
Does does ACA stroke stand for?
Anterior cerebral artery stroke
What does MCA stroke stand for?
Middle cerebral artery stroke
Where does most weakness occur in a stroke due to the anterior cerebral artery?
Leg more than arm weakness
Where does most weakness occur in a stroke due to middle cerebral artery?
Face and arm more than leg weakness