Stroke & TIA Flashcards
What is the definition of stroke?
a sudden onset, focal neurological deficit of presumed vascular origin that lasts for more than 24 hours
What is the definition of a TIA?
a sudden onset, focal neurological deficit of presumed vascular origin that resolves within 24 hours
What are the 2 different types of stroke?
haemorrhagic:
caused by vascular rupture
ischaemic:
caused by vascular occlusion or stenosis
vascular rupture causes blood to leak into the brain tissue
How can ischaemic strokes be further subdivided?
thrombotic:
due to atherosclerotic plaque formation
embolic:
due to a blood clot that has originated from elsewhere (e.g. AF)
What are the 6 major risk factors for stroke?
- smoking
- obesity
- hypertension
- diabetes
- high cholesterol
- old age
What are some less common risk factors for stroke?
- polycythaemia
- AF
- excessive alcohol consumption
- heart valve disease
- clotting disorders
- peripheral arterial disease
What are the general signs and symptoms of stroke?
Why does this vary?
stroke has an ACUTE onset
- limb weakness / numbness
- facial drooping
- speech difficulty
- dizziness
- loss of coordination / balance
- visual changes
presentation is influenced by which area of the brain is affected
What are the roles of the frontal and temporal lobes?
frontal lobe:
* personality / behaviour
* planning / decision making
* concentration
* primary motor cortex (precentral gyrus)
temporal lobe:
* understanding speech
* interpreting auditory + olfactory sensations
What are the roles of the parietal and occipital lobes?
parietal lobe:
* comprehension / language
* primary somatosensory cortex (postcentral gyrus)
* sensory functions
occipital lobe:
* vision
* processing visual information + storing visual memories
What are the roles of the brainstem and cerebellum?
brainstem:
* breathing / heart rate
* swallowing
* arousal / wakefulness
cerebellum:
* coordination + movement
* balance
Why does the affected artery produce different symptoms of stroke?
it depends on the vascular territory supplied by that artery and the function of that area
What key regions are supplied by the anterior cerebral artery (ACA)?
- medial + superior parts of frontal lobe
- anterior parietal lobe
What are the symptoms of anterior cerebral artery stroke?
- contralateral hemiparesis that tends to affect the lower limbs > upper limbs / face
- behavioural changes
What are the regions supplied by the middle cerebral artery (MCA)?
lateral parts of the frontal, parietal and temporal lobes
What are the associated signs of MCA stroke?
- contralateral hemiparesis affecting upper limbs / face > lower limbs
- contralateral hemisensory loss
- apraxia
- aphasia
- quandrantopias
What are the roles of Broca’s and Wernicke’s area?
Broca’s area:
* responsible for the production of speech
* damage to this area results in expressive aphasia
Wernicke’s area:
* responsible for the comprehension of speech
* damage to this area results in receptive aphasia
remember B for “buccal” - meaning mouth - where speech is produced
remember W for “what do you mean”
What regions are supplied by the posterior cerebral artery?
- occipital lobe
- inferior part of temporal lobe
What are the consequences of a posterior cerebral artery stroke?
- contralateral homonymous hemianopia
- visual agnosia (difficulty recognising familar faces / objects)
What parts of the brain are supplied by the posterior circulation?
- brainstem
- cerebellum
- occipital lobes
What is the result of a posterior circulation stroke?
- isolated hemianopia
- signs related to the brainstem and cerebellum
this includes:
* vertigo / imbalance
* slurred speech
* unilateral limb weakness
* double vision