Dr Paul Syme outlines the recommendations in the SIGN guideline on the assessment, investigation, immediate management, and secondary prevention of stroke and TIA

Stroke is one of the most important medical emergencies and also one of the main priorities for the Department of Health as indicated by the National Stroke Strategy.1 This is underlined in the SIGN guideline published in December 2008 on the Management of patients with stroke or TIA: Assessment, investigation, immediate management and secondary prevention (SIGN 108).2 This guideline replaces two previous guidelines published by SIGN in 1997 on the management of patients with stroke, which focused on: assessment, investigation, immediate management, and secondary prevention (SIGN 13);3 and the management of carotid stenosis and carotid endarterectomy (SIGN 14).4 Since the publication of these documents, there have been considerable developments in the field of stroke medicine, including evidence to support the use of thrombolysis within 4.5 hours of stroke symptoms, and the need for rapid carotid endarterectomy for significant carotid stenosis.2

The SIGN 108 guideline follows the patient pathway and includes advice on assessment, investigation, and immediate management. It provides practical evidence-based guidance for healthcare professionals, outlining useful recommendations for referral and secondary prevention; an accompanying patient booklet on stroke assessment is also available. The guideline complements the SIGN guidelines on stroke rehabilitation (SIGN 64),5 and dysphagia after stroke (SIGN 78),6 but does not cover the primary prevention of cardiovascular and cerebrovascular disease, which were the focus of SIGN 97.7 The new guideline will be used by NHS Quality Improvement Scotland to develop new standards for stroke.

The SIGN guideline is focused on the patient pathway with an emphasis on secondary care, and provides evidence for supporting rapid access to hospital for patients with stroke, and management thereafter. General practitioners will be involved in the referral process and after patient discharge from hospital, and they may also play a role in commissioning stroke services. Knowledge of this guideline is therefore essential for all GPs so that they can provide the best care for patients with stroke.

Rapid care following TIA or stroke

A stroke and transient ischaemic attack (TIA) share the same aetiology, but are distinguished by their duration: stroke lasts ?24 hours and a TIA <24 hours.2 A review of the definition of a TIA is needed as most of these attacks last 30–60 minutes.8 The cardinal features of a stroke include:

  • suddenness of onset
  • maximum symptoms and signs at onset
  • focal rather than global neurological signs consistent with damage in an arterial territory.

Brain damage following a stroke is time-dependent and to this end the SIGN 108 guideline emphasises the need to treat stroke and TIA as vascular emergencies. Rapid admission to hospital is essential for the welfare of the patient with suspected stroke. Emergency services should be redesigned to facilitate rapid access to specialist stroke services in hospital.2

Assessment

Use of standard assessment scales—such as the Face Arm Speech Test (FAST)9 or the Melbourne Acute Stroke Scale (MASS)10—is recommended by SIGN to aid identification of stroke by clinical staff in the community.2 The recognition of stroke in the emergency room (ROSIER) scale should be used by emergency department staff in hospital to confirm the diagnosis.11 (These three scales are included in the annex of the SIGN guideline, which is available at www.sign.ac.uk.) In areas without a local stroke specialist, telemedicine consultation should be considered to validate cases of stroke, and to direct acute therapy.2

One of the main issues for primary care will be ensuring rapid diagnosis and access to specialist stroke services in hospital. Primary care should have protocols in place to address suspected strokes cases, which should be referred immediately to specialist stroke services. Furthermore, patients and carers need to be able to recognise the signs of a stroke so that affected people can receive medical attention swiftly.

In order to reduce the delay in getting patients to hospital, emergency services should be contacted in most cases, and the GP informed. A GP review in the patient’s home is not recommended because this will increase the time taken for the patient to reach the hospital. However, GPs, if contacted by telephone or at their surgery, should treat stroke as an emergency and discuss these cases with the stroke service. Patients should be transferred to hospital if they are within the time scale for thrombolysis. If outside of this window, patients should still be treated as urgent cases. The use of FAST and the ROSIER scale in primary care may aid stroke identification. All patients who have had a stroke should be admitted to a dedicated stroke unit; this has been shown to reduce case fatality and length of stay.1,12 Therefore, it is important that all health boards allocate sufficient resources to ensure that all patients who have had a stroke have access to a bed within the first 24 hours of admission. The length of stay for patients who have had minor strokes will be short, but patients with major strokes will need to remain in the unit for as long as is necessary for the management of any major complications.

Investigations

In patients who have had a TIA, the ABCD2 score should be used to identify those individuals who are at the highest risk of recurrent stroke (this score can be found in the annex of the SIGN guideline, which is available at www.sign.ac.uk).2,13 The National Institute of Health Stroke Scale (NIHSS) (available at www.nihstrokescale.org) can be used to assess severity of stroke and has been shown to predict stroke outcome.2,14

Brain imaging

Brain imaging is essential to differentiate haemorrhagic and ischaemic events, and to exclude other conditions that mimic stroke, such as tumours. Patients who have had a stroke should be scanned immediately after clinical evaluation in hospital.2 Computerised tomography (CT) scanning remains the mainstay of brain imaging, but magnetic resonance imaging with diffusion weighted and gradient echo sequences can be used for ‘CT invisible strokes’, posterior circulation strokes, and patients presenting after 1 week.15

Carotid duplex scanning along with corroborative imaging, is recommended for minor stroke (modified Rankin score ?2)16 or TIA in the carotid territory to detect carotid stenosis.2

Echocardiography should be considered for cryptogenic stroke (a stroke in which no generally accepted cause is identified after investigation and the patient is aged <55 years) and for patients with suspected heart disease.2 Contrast echocardiography and/or transcranial Doppler (TCD) ultrasonography can be used to detect patent foramen ovale as paradoxical embolism is a greater possibility with cryptogenic stroke. These contrast studies should be restricted to the investigation of this particular group of patients.17

Treatment of stroke

Aspirin

Aspirin at a dose of 300 mg/day should be given to all patients within 48 hours of ischaemic stroke and continued for at least 2 weeks.2,18

Thrombolysis

Intravenous thrombolysis (alteplase 0.9 mg/kg up to a maximum of 90 mg) is recommended for all patients who have had ischaemic stroke (unless contraindicated) presenting within 4.5 hours from stroke onset.19 Every effort should be made to treat ischaemic stroke with thrombolysis as early as possible. Intra-arterial thrombolysis should be considered only in specialist centres. Mechanical reperfusion can be attempted in patients ineligible for thrombolysis but only in experienced centres.2,20 The SIGN guideline recommends the consideration of TCD ultrasonography in relation to thrombolysis, but only in the context of clinical trials. Since publication of the guideline, a large meta-analysis of 25 studies and 1813 patients has shown that TCD identification of arterial recanalisation is one of the best predictors of acute stroke outcome following middle cerebral artery occlusion.1,21

Blood pressure

In the acute phase of stroke, blood pressure should be actively monitored but at present there is a lack of evidence to support medical intervention.

Anticoagulation therapy

The SIGN guideline does not recommend the routine use of anticoagulants for the treatment of acute ischaemic stroke.2 Although, treatment with these agents should be considered in patients with cerebral venous thrombosis and extracranial artery dissection.22,23

Endarterectomy

Carotid stenosis is estimated using the North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria.24 Endarterectomy for symptomatic stenosis should be performed within 2 weeks of stroke onset,1,24 and should occur on the symptomatic side. This procedure should be considered in:2

  • male patients with 50–99% stenosis
  • female patients with 70–99% stenosis.

Endarterectomy for asymptomatic stenosis may be a treatment option in younger patients (aged <70 years), male patients, and those individuals with bilateral disease.25 This means that all suspected TIAs and minor strokes in the carotid territory should be referred to a stroke specialist as soon as possible. As most major strokes occur within 48 hours of these events this means that suspected TIAs and minor strokes also need to be treated as emergencies, and neurovascular clinics should be adapted to provide this service.

Decompression

Surgical decompression by hemicraniectomy is recommended for patients who present within 48 hours from stroke onset, are aged between 18 and 60 years, and who have malignant middle cerebral artery syndrome.1,26

Haemorrhagic stroke

There is a lack of evidence to support a specific treatment option for primary intracerebral haemorrhage.

Secondary prevention of stroke

As soon as intracerebral haemorrhage has been excluded and a diagnosis made, the following treatments can be initiated in either primary or secondary care.

Antiplatelet therapy

For secondary prevention of vascular events, aspirin (75 mg/day) and dipyridamole (200 mg modified release bd) should be given to all patients who have had ischaemic stroke.1,27 Clopidogrel (75 mg/day) monotherapy has been shown to be as effective as the aspirin and dipyridamole combination,28 and can be given as an alternative if patients are hypersensitive to aspirin, or if the patient has unstable angina or has had a recent myocardial infarction. It should also be considered if the patient does not tolerate dipyridamole. Antiplatelet therapy is also recommended for patients with cryptogenic stroke (transcatheter closure can be considered).2

Statin therapy

Data from the Heart Protection Study showed that statins should be given for all TIAs and strokes regardless of the cholesterol level,29 and there is evidence that atorvastatin reduces the risk of recurrent stroke events.30

Anticoagulant therapy

Anticoagulation therapy is recommended for all patients with atrial fibrillation after a TIA or ischaemic stroke because the risk of a recurrent event is high and warfarin is superior to aspirin for stroke prevention in this condition.1,31 If this treatment is contraindicated, these patients should receive aspirin.31

Management of blood pressure

Following stroke, healthcare professionals (this is likely to be the responsibility of the GP) should wait a minimum of 2 weeks (preferably 4 weeks) before prescribing antihypertensive treatment.32 For patients with hypertension, the SIGN guideline recommends a target blood pressure of <140/85 mmHg or <130/80 mmHg for patients with diabetes.2

Lifestyle modification

Patients should be given lifestyle advice to reduce the risk of recurrent TIA and stroke, such as:

  • keeping total and saturated fat intake at a low level
  • reducing salt intake if they have hypertension
  • increasing fruit consumption
  • the reduction of weight if overweight, and the maintenance of this reduction
  • quitting smoking
  • control of alcohol intake
  • lifelong participation in exercise.

Provision of information

Information on all aspects of stroke including investigations and outcomes should be given to patients and their relatives wherever possible and in a format that they understand.

Conclusion

It is important that GPs understand why it is necessary to treat both TIA and stroke as emergencies, and are familiar with the evidence-based recommendations for acute stroke treatment and secondary prevention. If implemented, the recommendations from the SIGN guideline on stroke and TIA should improve investigation and treatment for patients with these conditions. However, in implementing this guideline, health boards will have to meet several challenges, including:

  • improvement of education of the general public regarding stroke recognition
  • development of medical services to assess and treat stroke as an emergency
  • provision of an adequate number of stroke unit beds based on number of admissions and a safe length of stay. A stroke bed model from the Scottish Borders Stroke Study can be used to calculate occupancy and bed numbers (www.stroke.org.uk).33G
  • PBC consortia should work with their local PCT and secondary care colleagues to design local care pathways for stroke diagnosis, treatment, and aftercare
  • Commissioners should consider ensuring public awareness of stroke symptoms through effective local publicity campaigns (e.g. FAST)
  • All clinicians in contact with patients should be conversant with a suitable scoring scale/algorithm (e.g. ABCD2 score) to ensure optimal and timely treatment
  • In local urgent-care services contracts, consideration should be given to the inclusion of clauses on standards in following care pathways for diagnosis and investigation
  • Targets for blood pressure reduction post TIA/stroke in the SIGN guideline are considerably lower than the quality and outcomes framework audit standard
  • Local retrospective audits of time lapse from symptom presentation to thrombolysis (where indicated) could identify the areas where services need to be commissioned more effectively to ensure rapid treatment for stroke
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