Ischaemic stroke Flashcards
Etiologic factors
30-40% are cardioembolic.
- non valvular AF is one of the most common causes.
- 10% of patients over 75 have AF
- both paroxysysmal and chronic AF are significant RFs
- CHADsVASC can be used to determine risk of thromboembolic stroke
15-20% are due to large vessel extracranial disease.
- all patients with CVA relavent to the anterior circulation should have carotid imaging. Can be MRA, CTA or US
- carotid atherosclerosis at the bifurcation accounts for 10-12% of ischaemic strokes
Management of ischaemic stroke and AF
Warfarin is superior to aspirin and aspirin + clopidogrel. NOACS - alternatives to warfarin dabigatran - direct thrombin inhibitor Rivaroxaban - factor X1 inhibitor Apixaban - factor Xa inhibitor
Management of stroke + patient PFO
25% of the general population have a patent PFO. There is largely negative or conflicting clinical trials involving PFO closure and ischaemic stroke. Advice- antiplatelet agent, PFO closure device often reserved following 2nd stroke.
Significance of pulmonary shunts in stroke work up
Pulmonary shunts are often discovered on echo. Pulmonary shunts are most commonly seen in Osler Weber Rendu disease. This is also known as hemorrhagic telangectasia, and is AD characterised by telangiectasias in multiple organs. Patients may also have vascular malformations in the brain, but more commonly evaluated for cerebral ischemia relevant to pulmonary fistulae. Treatment is embolization of the fistulae. Antithrombotics are generally contraindicated because of the high risk of bleeding from nasal and gastrointestinal tract telangiectasias
Aortic dissection with stroke
Clues to a stroke due to aortic dissection may include chest or back pain, AR, hypotension, decreased peripheral pulses and a difference in BP reading between 2 arms. Dx - widened mediastinum - CT chest.
Treatment of symptomatic carotid artery stenosis?
Symptomatic refers to a cerebral infarction of TIA in the anterior circulation ipsilateral to the atheromatous diseased internal carotid artery. NASCET trial CREST trial (endarterectomy vs stenting) ICSS (international carotid stenting study)
Current recommendation: for patients with receent cerebral ischaemia (6 months) due to ipsilateral stenosis of 70-99%, carotid endarterectomy is recommended if the perioperative morbidity is less than 6%.
Selected patients with moderate grade stenosis could be considered for carotid endarterectory if perioperative morbidity and mortality are less than 6%
In patients with carotid artery occlusion medication management is superior to surgical management
After caotid intervention - antiplatelet management iand rf management
Extracranial dissection
Can affect either carotid or vertebral arteries
Common cause of stroke in under 45s
50% of dissections result from identifiable trauma
Conditions predisposing - fibromuscular dysplasia, vascular type of Ehlers-Danlos syndrome, Marfans, PCKD, pseudoxanthoma elasticum, osteogenesis imperfecta.
Optimum treatment controversial - generally anticoagulation for 3-6 months then reimage
internal carotid artery dissection
generally occurs 2-3cm distal to the bifurcation and may have a flamelike tapering on angiography.
Often presents with anterolateral cervical and retro-orbital pain
Horner’s syndrome (due to sympathetics traveling near the carotid artery) and anterior circulation syndromes
vertebral artery dissections
typically occur at C1-2 where the artery courses posteriorly and enters the foramen magnum
Posterior head pain and lateral medullary syndrome
What is fibromuscular dysplasia
Nonatherosclerotic noninflammatory arteriopathy.
Tunica media vasorum is characterised by disorganised smooth muscle cells, loss of smooth muscle cells, and general disorganization of the arterial wall.
Internal elastic lamina is disrupted
More common in white women, affects renal vessels most commonly but also extracranial carotid or vertebral arteries.
Predisposes to arterial dissection,
