Stroke Flashcards
Ischaemic stroke
Blockage in the blood vessel stops blood flow
Ischaemic stroke subtypes
Thrombotic stroke - thrombosis from large vessels eg. carotid
Embolic stroke - usually a blood clot but fat, air or clumps of bacteria may act as an embolus
- AF
Ischaemic stroke risk factors
General risk factors for cardiovascular disease
Age
HTN
Smoking
Hyperlipidaemia
Diabetes mellitus
AF
Oxford stroke classification
Classifies strokes based on the initial symptoms
Criteria:
1) unilateral hemiparesis and/or hemisensory loss of the face, arm & leg
2) homonymous hemianopia
3) higher cognitive dysfunction e.g. dysphagia
TACI
Involves middle and anterior cerebral arteries
1) unilateral hemiparesis and/or hemisensory loss of the face, arm & leg
2) homonymous hemianopia
3) higher cognitive dysfunction e.g. dysphagia
PACI
Involves smaller arteries of anterior circulation eg. upper/lower division of middle cerebral artery
2 of the following present:
1) unilateral hemiparesis and/or hemisensory loss of the face, arm & leg
2) homonymous hemianopia
3) higher cognitive dysfunction e.g. dysphagia
LACI
Involves perforating arteries around the internal capsule, thalamus & basal ganglia
Presents with 1 of the following:
1) unilateral weakness (and/or sensory deficit) of face and arm, arm and leg or all three.
2) pure sensory stroke
3) ataxic hemiparesis
POCI
Involves vertebrobasilar arteries
Presents with 1 of the following:
1) cerebellar or brainstem syndromes
2) loss of consciousness
3) isolated homonymous hemianopia
Other types of stroke
Lateral medullary syndrome (PICA) aka Wallenberg’s syndrome
- ipsilateral: ataxia, nystagmus, dysphagia, facial numbness, CN palsy (eg. Horner’s)
- contralateral: limb sensory loss
Weber’s syndrome (branches of posterior cerebral artery that supply the midbrain)
- ipsilateral III palsy
- contralateral weakness
Lateral pontine syndrome (AICA)
- symptoms similar to Wallenberg’s
- ipsilateral: facial paralysis and deafness
Retinal/ophthalmic artery
- Amaurosis fugax
Basilar artery
- ‘Locked-in’ syndrome
FAST campaign
Face - has face fallen on one side? can they smile?
Arms - can they raise both arms & keep them there?
Speech - is it slurred?
Time - call 999 if see any of these signs
ROSIER score
Exclude hypoglycaemia first
LOC or syncope -1
Seizure activity -1
New, acute onset of:
Asymmetric facial weakness +1
Asymmetric arm weakness +1
Speech disturbance +1
Visual field defect +1
Stroke likely > 0
Ischaemic stroke ix
Non-contrast CT head scan - differentiate ischaemic vs haemorrhagic
- areas of low density & white matter of the territory → changes may take time to develop
- ‘hyperdense artery’ → corresponding with the responsible arterial clot; visible immediately
General management principles for stroke
Blood glucose, hydration, oxygen saturation & temperature should be maintained within normal limits
BP not lowered in acute phase
Aspirin 300mg given ASAP if haemorrhagic stroke has been excluded
AF → anticoagulants should not be started until 14 days after ischaemic stroke
Cholesterol > 3.5mmol/L, pt commenced statin (delay for 48 hrs → haemorrhagic transformation)
Thrombolysis for acute ischaemic stroke
Administered within 4.5 hours of onset of stroke symptoms
Haemorrhage has been definitively excluded
Contraindications to thrombolysis
Absolute - previous intracranial haemorrhage, seizure at onset of stroke, intracranial neoplasm, stroke/traumatic brain injury in preceding 3 months, LP in past 7 days, active bleeding, pregnancy
Relative - concurrent anticoagulation (INR > 1.7), haemorrhagic diathesis, active diabetic haemorrhage retinopathy, major surgery/trauma in preceding 2 weeks
Thrombectomy for acute ischaemic stroke
Offer ASAP & within 6 hours of symptom onset, together with IV thrombolysis (if within 4.5 hours), to people who have:
- acute ischaemic stroke
- confirmed occlusion of proximal anterior circulation (CTA/MRA)
Offer ASAP to people who were last known to be well between 6 hours & 24 hours previously:
- confirmed occlusion of proximal anterior circulation (CTA/MRA)
- potential to salvage brain tissue
Consider with IV thrombolysis (if within 4.5 hours) ASAP for people last known to be well up to 24 hours previously:
- acute ischaemic stroke & confirmed occlusion of proximal posterior circulation (basilar/PCA)
- potential to salvage brain tissue
Ischaemic stroke secondary prevention
Clopidogrel
Aspirin is now recommended only if clopidogrel is contraindicated/not tolerated
Carotid artery endarterectomy:
- patient has suffered stroke/TIA in carotid territory and are not severely disabled
- should only be considered if carotid stenosis > 70% according ECST criteria or > 50% according to NASCET criteria
Post-stroke fluid mx
Ensure patients remain normovolaemic
Oral hydration is preferable in all patients who are able to safely swallow
- IV hydration otherwise - isotonic saline without dextrose
- take into account any electrolyte disturbances and/or CVS status
Post-stroke glycaemic control
Closely monitor and control blood sugar
Maintaining a blood sugar level between 4 & 11mmol/L in people with acute stroke
Diabetic patients - optimise insulin treatment, manage hypoglycaemia appropriately
Post-stroke BP mx
Use of anti-hypertensive medications should only be used for BP control in patients post ischaemic stroke if HTN emergency
Lowering BP too much → compromise collateral blood flow to affected region
Patients who are candidates for thrombolytic therapy for acute stroke, BP reduced to 185/110mmHg or lower
Post-stroke feeding assessment & mx
Screen for safe swallow
Any concerns → specialist assessment of swallowing (preferably within 24 hours)
Deemed unsafe for oral intake:
- NGT feed, within 24 hours of admission
- Nasal bridle tube/gastrostomy if NGT not tolerated
Nutritional support
Post-stroke disability scales
Medically stabilised → transfer to a rehab team for ongoing treatment depending on level of disability
Barthel index - used to assess functional status of a patient post stroke & monitor their improvement with ongoing rehab to regain independence after the event
Haemorrhagic stroke
Blood vessel ‘bursts’ leading to reduction in blood flow
Haemorrhagic stroke subtypes
Intracerebral haemorrhage - bleeding within the brain
Subarachnoid haemorrhage - bleeding on the surface of the brain
Haemorrhagic stroke risk factors
Age
Hypertension
AVN malformation
Anticoagulation therapy
Symptoms patients who have had haemorrhagic strokes are more likely to experience
Decrease in the level of consciousness
Headache
N&V
Seizures
Haemorrhagic stroke ix
Emergency neuroimaging - CT/MRI
- areas of hyperdense material (blood) surrounded by low density (oedema)
Haemorrhagic stroke mx
Neurosurgical referral
Supportive mx - anticoagulants & antithrombotic meds should be stopped, BP lowered acutely
TIA
Brief period of neurological deficit due to a vascular cause, typically lasting less than an hour
Transient episode of neurologic dysfunction caused by focal brain, spinal cord or retinal ischaemia without acute infarction
TIA clinical features
Features resolve, typically within 1 hour
Possible features include:
- unilateral weakness/sensory loss
- Aphasia or dysarthria
- ataxia, vertigo or loss of balance
- visual problems
- amaurosis fugax (sudden transient loss of vision in one eye)
- diplopia
- homonymous hemianopia
TIA initial mx
Give aspirin 300mg immediately unless:
1) pt has bleeding disorder/taking anticoagulant
2) patient is already taking low-dose aspirin
3) aspirin is contraindicated
TIA referral for specialist review
If patient has had more than 1 TIA/suspected cardioembolic source/severe carotid stenosis:
- discuss the need for admission/observation urgently with a stroke specialist
If patient has had a suspected TIA in the last 7 days:
- arrange urgent assessment within 24 hours by a specialist stroke physician
If patient has had a suspected TIA which occurred more than a week previously:
- refer for specialist assessment ASAP within 7 days
TIA ix
Neuroimaging - MRI preferred
Carotid imaging - urgent carotid doppler
TIA further mx
Secondary prevention
- antiplatelet therapy to follow on from initial aspirin therapy → clopidogrel first line
Lipid modification
- high-intensity statin
Carotid artery endarterectomy if indicated
