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
