Stroke Flashcards
Define stroke
A serious life threatening condition that occurs when the blood supply to part of the brain is cut off
Define transient ischaemic attack
Similar clinical features of stroke but resolve within 24 hours
Different between stroke and TIA
Similar clinical features but TIA < 24 hours
Types of stroke
- ischaemic: thromboembolic
- haemorrhagic: intracerebral + subarachnoid
- other: dissection, venous sinus thrombosis, hypoxic brain injury
Emergency management of stroke
- are they within the window for thrombolysis (<4 hours)?
- CT head to determine if bleed
Imaging of stroke
CT head
MRI
Stroke symptoms of anterior cerebral artery infarction
- contralateral weakness in lower limb (supplies medial homonculus)
- contralateral sensory changes in same pattern as motor deficits
- urinary incontinence
- apraxia
- dysarthria/aphasia
- split brain syndrome/alien hand syndrome
What is apraxia?
Inability to complete normal day to day motor tasks
e.g. difficulty dressing oneself (buttons) even when power is normal
Why can anterior cerebral artery infarction cause urinary incontinence?
Paracentral lobule affected
Controls motor + sensory innervations to contralateral lower extremity > responsible for control of urination + defecations
Main points of occulsion of the middle cerebral artery
- Main stem (proximal)
- Lenticulostriate arteries
- Cortical branches
- Inferior division
- Superior division
Stroke symptoms due to proximal middle cerebral artery infarct
- contralateral hemiparesis of face, arm + leg
- contralateral sensory loss
- contralateral homonymous hemianopia without macular sparing
- global aphasia (broca’s + wenicke’s) if left sided
- right sided neglect if right sided
What is alien hand syndrome?
A phenomenon in which one hand is not under control of the mind /hand acts as if it has a mind of its own
Types of stroke symptoms due to lenticulostriate arteries infarct (lacunar infarct)
- neglect, aphasia + visual field defects not present
- pure motor stroke: face, arm + legs weakness
- pure sensory stroke face, arm + legs sensory loss/change
- sensorimotor stroke: mixture of both
Difference between lacunar infarct + proximal middle cerebral artery infarct symptoms
Neglect, aphasia + visual field defect absent in lacunar infarct
Stroke symptoms of inferior division of middle cerebral artery infarct
- inferior division supplies lateral parietal + superior temporal lobe
- contralateral sensory change in face + arms
- receptive/Wernicke’s aphasia if left sided
- homonymous hemianopia
What artery is most common affected in strokes?
Middle cerebral artery
What does the inferior division of middle cerebral artery supply?
Lateral parietal - primary sensory cortex
Superior temporal lobe - Wenicke’s area
What does the superior division of the middle cerebral artery supply?
Lateral frontal lobe - Broca’s area
Stroke symptoms due to superior division of middle cerebral artery infarct
- contralateral face + arm weakness
- expressive/Broca’s aphasia if left sided
Stroke symptoms due to posterior cerebral artery infarct
- contralateral homonymous hemianopia with macular sparing
- contralateral sensory loss/change due to involvement of thalamoperforator/thalamogeniculate branches
Symptoms + signs of cerebellar strokes
- N + V
- vertigo/dizziness
- headache
- ipsilateral cerebellar signs DANISH
- ipsilateral cranial nerve signs
- contralateral sensory deficit
- ipsilateral Horner’s syndrome
What supplies the internal capsule?
Lenticulostriate arteries
What is neglect?
Failure to acknowledge the existence of the left side of space, objects + their own body
Signs of neglect
Tactile + visual extinction
Anosognosia/lack of insight
Why can a basilar artery occulsion cause sudden death?
Supplies brainstem which contains many vital centres
Presentation of distal (superior) basilar artery infract
- visual + oculomotor deficits
- behavioural abnormalities
- hallucinations, somnolence + dreamlike behaviour
Why is motor dysfunction usually absent in basilar artery occlusion?
Cerebral peduncles ‘rescued’ by posterior communicating artery
Presentation of proximal (at level of pontine branches) basilar artery infract
- locked in syndrome
- complete loss of movement of limbs
- preserved ocular movement due to Pcomm supply
- preserved consciousness
What is used to classify strokes?
Bamford (oxford) stroke classification
Presentation of brainstem strokes
Ipsilateral brainstem signs
Contralateral motor + sensory deficits
What cranial nerve is at risk in a posterior communicating artery aneurysm?
Oculomotor
Runs parallel
What is anosogonsia?
Condition in which a patients is unaware of their neurological deficit or psychiatric condition
Lack of insight
