Stroke

• Stroke, also known as cerebrovascular accident (CVA), is a medical condition that occurs when the blood supply to the brain is disrupted, causing brain tissue to ischemia or infarction.
• Cerebrovascular accidents can be ischaemia or infarction of the brain tissue secondary to a disrupted blood supply (ischaemic stroke), intracranial haemorrhage, with bleeding in or around the brain (haemorrhagic stroke), or a combination of both (mixed stroke).
• Ischaemia refers to an inadequate blood supply.
• Infarction refers to tissue death due to ischaemia.
• The blood supply to the brain may be disrupted by a thrombus or embolus, atherosclerosis, shock, vasculitis, or transient ischaemic attack (TIA).
• Transient ischaemic attack (TIA) involves temporary neurological dysfunction (lasting less than 24 hours) caused by ischaemia but without infarction.
• Symptoms of TIA have a rapid onset and often resolve before the patient is seen.
• Crescendo TIAs are two or more TIAs within a week and indicate a high risk of stroke.
• A sudden onset of neurological symptoms suggests a vascular cause (e.g., stroke).
• Stroke symptoms are typically asymmetrical.
• Common symptoms of stroke include limb weakness, facial weakness, dysphasia (speech disturbance), visual field defects, sensory loss, ataxia and vertigo (posterior circulation infarction).
• Previous stroke or TIA, atrial fibrillation, carotid artery stenosis, hypertension, diabetes, raised cholesterol, family history, smoking, obesity, vasculitis, thrombophilia, combined contraceptive pill carry a higher risk of stroke.
• The combined contraceptive pill carries a tiny increased risk of stroke, with a higher risk in patients with migraines with aura, smokers over 34 years or those with a history of stroke or TIA.
• The FAST tool is used as a simple way to identify stroke in the community: F - Face, A - Arm, S - Speech, T - Time (act fast and call 999).
• The ROSIER tool (Recognition Of Stroke In The Emergency Room) gives a score based on the clinical features and duration.
• Surgical interventions are considered where there is significant carotid artery stenosis and the options are carotid endarterectomy, angioplasty and stenting.
• Initial management of TIA involves aspirin 300mg daily, referral for specialist assessment within 24 hours, and a Diffusion-weighted MRI scan.
• Patients with a TIA or stroke are investigated for carotid artery stenosis and atrial fibrillation with carotid imaging, ECG or ambulatory ECG monitoring, and anticoagulation is initiated for atrial fibrillation after excluding haemorrhage and finishing two weeks of aspirin.
• Thrombectomy is considered in patients with a confirmed blockage of the proximal anterior circulation or proximal posterior circulation and may be considered within 24 hours of the symptom onset and alongside IV thrombolysis.
• Stroke patients require a period of adjustment and rehabilitation involving a multi-disciplinary team of stroke physicians, nurses, speech and language (SALT) to assess swallowing, dieticians in those at risk of malnutrition, physiotherapy, occupational therapy, social services, optometry and ophthalmology, psychology, orthotics, and more.
• Management of stroke involves excluding hypoglycaemia, immediate CT brain to exclude haemorrhage, aspirin 300mg daily for two weeks, admission to a specialist stroke centre, and thrombolysis with alteplase once haemorrhage is excluded.
• Stroke is possible in patients scoring one or more on the ROSIER tool.
• Patients with a stroke need close monitoring for complications, particularly intracranial or systemic haemorrhage, with access to immediate imaging if bleeding is suspected.
• Blood pressure is aggressively treated in patients with a haemorrhagic stroke.
• Alteplase is a tissue plasminogen activator that rapidly breaks down clots and may be given within 4.5 hours of the symptom onset, based on local protocols and by an appropriately trained team.
• All patients with a TIA or stroke will have carotid imaging and ECGs to identify these risk factors.
• Management of TIA symptoms should have completely resolved within 24 hours of onset.
• Secondary prevention for stroke patients involves clopidogrel 75mg once daily, atorvastatin 20-80mg, blood pressure and diabetes control, addressing modifiable risk factors, rehabilitation, and assessment for underlying causes.
• In patients with an ischaemic stroke, lowering the blood pressure can worsen the ischaemia and high blood pressure treatment is only indicated in hypertensive emergency or to reduce the risks when giving intravenous thrombolysis.