A cerebrovascular event (stroke) is a clinical syndrome caused by disruption of blood supply to the brain, characterised by rapidly developing signs of focal or global disturbance of cerebral functions, lasting for more than 24 hours or leading to death. A transient ischaemic attack (TIA) refers to a similar presentation that resolves within 24 hours.
A stroke results either from ischaemic infarction of part of the brain or from intracerebral haemorrhage. Ischaemic infarction may be caused by atheroma or thromboembolism and, more rarely, by trauma, infection or tumours.
- Cerebral infarction accounts for about 70% of strokes.
- Primary haemorrhage accounts for about 15%.
- Subarachnoid haemorrhage accounts for approximately 5%. See separate Subarachnoid Haemorrhage article.
- The remainder are of uncertain type.
- Subarachnoid haemorrhage.
- Venous sinus thrombosis.
- Carotid artery dissection, eg via near-strangling or fibromuscular dysplasia.
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- Thrombosis in situ.
- Athero-thromboembolism, eg from carotid arteries.
- Heart emboli (particularly associated with atrial fibrillation, infective endocarditis or myocardial infarction).
- Central nervous system (CNS) bleed (associated with hypertension, head injury, aneurysm rupture).
- Sudden blood pressure drop by more than 40 mm Hg.
- Vasculitis, eg giant cell arteritis.
- Venous sinus thrombosis.
Stroke is a major health problem in the UK:
- An estimated 150,000 people have a stroke in the UK each year.
- There are over 53,000 deaths due to stroke each year in the UK.
- A further 20,000 people have a TIA.
- Diabetes mellitus.
- Heart disease (valvular, ischaemic, atrial fibrillation).
- Peripheral vascular disease.
- Post-TIA (TIAs are associated with a high early risk of stroke).
- Polycythaemia vera.
- Carotid artery occlusion; carotid bruit.
- Combined oral contraceptive pill.
- Excess alcohol.
- Clotting disorders.
- Either sudden onset or a step-wise progression of symptoms and signs over hours (or even days) is typical.
- In people with sudden onset of neurological symptoms, a validated tool, such as FAST (= F ace, A rm, S peech, T ime to call 999), should be used outside hospital to screen for a diagnosis of stroke or TIA.
- Focal signs relate to distribution of the affected artery, but collateral supplies may cause variation in the presentation.
- Cerebral hemisphere infarcts (50%) may cause:
- Brainstem infarction (25%):
- Lacunar infarcts (25%):
- Small infarcts around the basal ganglia, internal capsule, thalamus and pons.
- May cause pure motor, pure sensory, mixed motor and sensory signs, or ataxia.
- Intact cognition/consciousness.
- The two types of stroke are not reliably distinguishable clinically but pointers include:
- CNS tumour.
- Subdural bleed.
- Todd's palsy.
- Consider a drug overdose if the patient is comatose.
- FBC - thrombocytopenia, polycythaemia.
- Test for sickle cell disease.
- Erythrocyte sedimentation rate (ESR) - giant cell arteritis (consider temporal lobe artery biopsy, start steroids).
- Hypoglycaemia, hyperglycaemia and hyperlipidaemia.
- Syphilis - active, untreated.
- Emboli from the left atrium may have caused the stroke. Look for a large left atrium on CXR and consider echocardiography.
- Post-myocardial infarction - mural thrombus is best shown by echocardiography.
- Brain imaging should be undertaken as soon as possible in all patients. Brain imaging should be undertaken immediately if the patient:
- Has indications for thrombolysis or early anticoagulant treatment.
- Is currently taking anticoagulant treatment.
- Has a known bleeding tendency.
- Has a depressed level of consciousness (Glasgow Coma Score below 13).
- Has unexplained progressive or fluctuating symptoms.
- Has papilloedema, neck stiffness or fever.
- Has severe headache at onset of stroke symptoms.
- Brain imaging:
- CT scanning is recommended for most patients in the acute phase of stroke. CT is widely available, practical, quick and easy to use in ill patients.
- CT is very sensitive in diagnosing haemorrhage in patients in the acute stage.
- In patients with ischaemic stroke, especially those with mild neurological deficits, CT imaging is often normal in the first few hours but the accuracy for ischaemic stroke delineation improves after six hours. However, CT remains less accurate than MRI for determining the site and extent of ischaemic damage, particularly for small lesions and posterior fossa lesions. The accuracy of CT is reduced after one week following the stroke event, especially distinguishing between haemorrhagic and ischaemic stroke origin.
- MRI may be contra-indicated in up to a fifth of patients because they are too ill, confused, dysphasic, have an intraocular or intracerebral metallic foreign body or have a pacemaker.
- Infective endocarditis: 20% of those with endocarditis present with CNS signs due to septic emboli from valves.
- Carotid duplex ultrasound: in stroke or TIA in carotid territory.
Acute stroke management
- Patients should be admitted to hospital (ideally a stroke unit for initial care and treatment, unless the diagnosis will make no difference to management, eg where the optimal management is palliative care).
- Maintenance or restoration of homeostasis:
- Oxygen therapy; give supplemental oxygen only if oxygen saturation drops below 95%.
- Blood sugar control; maintain blood glucose concentration between 4 and 11 mmol/L. Provide optimal insulin therapy with intravenous insulin and glucose, for people with diabetes.
- Blood pressure control:
- There is currently insufficient evidence to reliably evaluate the effect that altering blood pressure has on the outcome after acute stroke.
- Give antihypertensive treatment only if there is a hypertensive emergency with one or more of the following:
- Consider blood pressure reduction to 185/110 mm Hg or lower in people who are candidates for thrombolysis.
- People with acute stroke should have their swallowing screened before being given any oral food, fluid or medication. Also screen for malnutrition.
- Aspirin (300 mg) should be given as soon as possible after the onset of stroke symptoms once a diagnosis of primary haemorrhage has been excluded. Antiplatelet therapy should then be continued indefinitely. Therapy should be delayed for 24 hours following thrombolysis. Clopidogrel 75mg daily is recommended.
- Thrombolytic treatment: see separate article Thrombolytic Treatment of Acute Ischaemic Stroke. Unless there are contra-indications, thrombolytic treatment appears to be effective in improving prognosis after an acute stroke. Treatment with alteplase should only be given provided that:
- It is administered within four and a half hours of onset of stroke symptoms (unless as part of a clinical trial).
- Haemorrhage has been definitively excluded.
- Anticoagulants should not be started until brain imaging has excluded haemorrhage. In patients with acute ischaemic stroke, immediate anticoagulant therapy is not associated with any overall short or long-term benefit. Treatment with anticoagulants reduces recurrent stroke, deep vein thrombosis and pulmonary embolism, but increases bleeding risk. Therefore anticoagulants should not be used routinely for patients with acute ischaemic stroke.
- Drugs depressing the function of the CNS (eg anxiolytics and tranquilisers) and new prescriptions for sedatives should be avoided.
- Do not start statin treatment immediately after an acute stroke, but continue statin treatment for people with acute stroke who are already taking statins.
- Encourage the person to sit up and mobilise as soon as their clinical condition permits.
- Patients with TIA, or patients with a stroke who have made a good recovery when seen, should be assessed and investigated in a specialist service (eg a neurovascular clinic) as soon as possible and within seven days of the incident.
Subarachnoid haemorrhage should be considered in any patient presenting with sudden-onset, severe and unusual headache with or without any associated alteration in consciousness. See the separate Subarachnoid Haemorrhage article.
- Surgical intervention should be considered in cases of supratentorial haemorrhage with mass effect or posterior fossa/cerebellar haematoma.
- Neurosurgical opinion should be sought for cases of secondary hydrocephalus.
- Carotid endarterectomy: see the separate Carotid Artery Occlusion article and the separate article Stroke Prevention.
- There is currently insufficient evidence to support intracranial stenting, unless part of research protocol.
- Consider referring for surgical decompressive hemicraniectomy if middle cerebral artery (MCA) infarction is present and all the following are met (refer within 24 hours of symptom onset and perform surgery within 48 hours of symptom onset):
- Aged 60 years or under.
- Clinical deficits suggestive of infarction in the territory of the MCA.
- Decrease in the level of consciousness.
- Signs on CT scan of an infarct of at least 50% of MCA territory or infarct volume greater than 145 cm3 as shown on diffusion-weighted MRI.
Secondary prevention of stroke and TIAs
Please see separate article Cerebrovascular Event Rehabilitation.
Patients who have suffered a stroke remain at an increased risk of a further stroke (between 30% and 43% risk within five years).  The risk of a further stroke is highest early after the stroke or TIA.
Patients with TIA and stroke also have an increased risk of myocardial infarction and other vascular events.
By six months, over half of stroke survivors will need some help with activities of daily living. 15% will have communication impairments and 53% motor weakness, and many will have problems with mood or cognition.
Dysphagia affects a large proportion of stroke patients. Swallowing difficulties can result in reduced fluid and food intake, and cause aspiration, which can lead to aspiration pneumonia, undernutrition and dehydration.
Other complications for the patient include thromboembolism, pneumonia, depression, contractures, bladder and bowel problems (eg incontinence, constipation) and bed sores.
NB: morbidity within carers is high - in particular stress, which is only partly relieved by respite admissions.
- Most people survive a first stroke, but often have significant morbidity.
- Mortality is 20% at one month and then 5-10% per year thereafter.
- Drowsiness suggests a poorer prognosis.
- See separate Stroke Prevention article and separate article Primary Prevention of Cardiovascular Disease.
ABCD prognostic score for people with a TIATotal scores range from 0 (low risk) and 7 (high risk):
- A - age (1 point where aged 60 or over).
- B - blood pressure (1 point for blood pressure of 140/90 mm Hg, or higher).
- C - clinical features (2 points for unilateral weakness; 1 point for speech disturbance without weakness).
- D - duration of symptoms (2 points for 60 minutes or longer; 1 point for 10-59 minutes).
People who have had a suspected TIA who are at high risk of stroke (ie an ABCD score of 4 or above) should have aspirin (300 mg daily) started immediately, specialist assessment and investigation within 24 hours of onset of symptoms and measures for secondary prevention introduced as soon as the diagnosis is confirmed, including discussion of individual risk factors.
General Medical Services Contract Quality Framework audit criteria
Quality and outcomes framework guidance: stroke and TIA (April 2012):
- STROKE 1: the practice can produce a register of patients with stroke or TIA: 2 points.
- STROKE 13: the percentage of new patients with a stroke or TIA who have been referred for further investigation: 2 points; payment stages 45-80%.
- STROKE 6: the percentage of patients with a history of TIA or stroke in whom the last blood pressure reading (measured in the previous 15 months) is 150/90 mm Hg or less: 5 points; payment stages 40-75%.
- STROKE 7: the percentage of patients with TIA or stroke who have a record of total cholesterol in the previous 15 months: 2 points; payment stages 50-90%.
- STROKE 8: the percentage of patients with TIA or stroke whose last measured total cholesterol (measured in the previous 15 months) is 5 mmol/L or less: 5 points; payment stages 40-65%.
- STROKE 12: the percentage of patients with a stroke shown to be non-haemorrhagic, or a history of TIA, who have a record that an antiplatelet agent (aspirin, clopidogrel, dipyridamole or a combination), or an anticoagulant, is being taken: 4 points; payment stages 50-90%.
- STROKE 10: the percentage of patients with TIA or stroke who have had influenza immunisation in the preceding 1 September to 31 March: 2 points; payment stages 45-85%.
Further reading & references
- Stroke: The diagnosis and acute management of stroke and transient ischaemic attacks, NICE Clinical Guideline (July 2008)
- Ovbiagele B, Cruz-Flores S, Lynn MJ, et al; Early stroke risk after transient ischemic attack among individuals with Arch Neurol. 2008 Jun;65(6):733-7.
- Management of patients with stroke: Identification and management of dysphagia, Scottish Intercollegiate Guidelines Network - SIGN (June 2010)
- Management of patients with stroke or TIA: assessment, investigation, immediate management and secondary prevention; Scottish Intercollegiate Guidelines Network - SIGN (December 2008)
- No authors listed; Organised inpatient (stroke unit) care for stroke. Cochrane Database Syst Rev. 2007 Oct 17;(4):CD000197.
- Geeganage C, Bath PM; Vasoactive drugs for acute stroke. Cochrane Database Syst Rev. 2010 Jul 7;(7):CD002839.
- National clinical guidelines for stroke (fourth edition), Royal College of Physicians, 2012
- Sandercock PA, Counsell C, Gubitz GJ, et al; Antiplatelet therapy for acute ischaemic stroke. Cochrane Database Syst Rev. 2008 Jul 16;(3):CD000029.
- Wardlaw JM, Murray V, Berge E, et al; Thrombolysis for acute ischaemic stroke. Cochrane Database Syst Rev. 2009 Oct 7;(4):CD000213.
- Sandercock PA, Counsell C, Kamal AK; Anticoagulants for acute ischaemic stroke. Cochrane Database Syst Rev. 2008 Oct 8;(4):CD000024.
- Endovascular stent insertion for intracranial atherosclerotic disease, NICE Interventional Procedure Guideline (October 2007)
- Vascular disease - clopidogrel and dipyridamole, NICE Technology Appraisal Guideline (December 2010)
- Quality and outcomes framework, British Medical Association
|Original Author: Dr Colin Tidy||Current Version: Dr Colin Tidy||Peer Reviewer: Dr John Cox|
|Last Checked: 16/05/2012||Document ID: 1925 Version: 32||© EMIS|
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