Stroke 1 Flashcards
What is a stroke ?
- Damage to part of the brain due to the blockage of a blood vessel by thrombus or embolus
- or due to haemorrhage from rupture of a blood vessels
Describe the anterior + posterior circulation
- supplies the supratentorial structures except the occipital. Arteries originate from the circle of willis
- supplies posterior portion ( occipital, cerebellum, brainstem)
What is the circle of willis?
-anastomosis between 2 vertebral and 2 internal carotid arteries. Gives branches
Describe the vascular supply
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Neurological history/examination of stroke
- Motor(clumsy/weak limb)
- Sensory ( loss of feeling)
- Speech ( dysarthria/dysphasia)
- Neglect/visuopatial problems
- Vision: loss in one eye/hemianopia gaze palsy
- ataxia/vertigo/incoordination/nyastagmus
Causes of a stroke
-blockage of vessel with thrombus / clot
-disease of vessel wall
-disturbance normal properties of blood
-rupture vessel wall
(haemorrhage)
Types of stroke
ischemic(common) + haemorrhagic stroke
What is a haemorrhagic stroke/ischemic stroke?
haemorrhagic stroke - BV ruptures and blood leaks into brain tissue > haematoma which will compress and surround surrounding brain tissue
Ischemic stroke - blockage/clot in an artery which reduces blood supply to the brain. Ischemia
State the causes of ischaemic stroke
- large artery atherosclerpsis ( eg carotid)
- cardioembolic ( eg atrial fibrilation)
- small artery occlusion ( lacunar)
- undetermined/cryptogenic
Rare causes
- arterial dissection
- venous sinus thrombosis
State the causes of haemorrhagic stroke
- primary intracerebral haemorrhage
- secondary haemorrhage ( subarachnoid + atriovenous malformation)
symptoms of stroke
-dependent on which artery/area of brain is affected
State the stroke subtypes
- total anterior circulation stroke
- partial anterior circulation stroke
- lacunar stroke
- posterior circulation stroke
What is a total anterior circulation stroke(TACS)?
- 20 %
- stroke due to occlusion of middle cerebral artery/internal carotid artery
- symptoms include weakness, sensoey deficity, homonymous hemianopia ( loss of vission) + higher cerebral dysfunction ( dysphasia
What is partial anterior circulation stroke?
- 35%
- cotyical infarcts involving occlusion of branches of middle cerebral artery
What is a cortical stroke?
-stroke that affects the cortex region of the brain
What is a lacunar stroke?
- 20%
- stroke that affects small BVs
- 3 types : pure motor, pure sensory, sensorimotor
- often silent/undiagnised
What are pure motor/sensory, sensorimotor strokes?
Pure motor
- complete/incomplete weakness of 1 side involving the whole of 2 of 3 body areas( face/arm/leg)
Pure sensory
-sensory symptoms and/ore signs ‘’ ‘’
Sensorimotor
-combination of both
What is a posterior circulation stroke?
25% of stoke
- affects brain stem, cerebellar/occipital lobes
- complex presentation that may include:
- bilateral motor/sensory deficit, disordered conjugate eye movement, isolated homonymous hemianopia, ipsilateral cranial nerve palsy with contralateral motor/sensory deficity.
- coma, disordered breathing, tinnitus, vertigo’s, hornoers syndrome
Risk factors for stroke
- HBP, atrial fibrilation (modifiable)
- age, race, FMX ( non modifiable)
