Chapter 130: Stroke and transient ischaemic attacks

Glossary of terms

Stroke A focal neurological deficit lasting longer than 24 hours caused by intracerebral haemorrhage or infarction.

Stroke in evolution An enlarging neurological deficit, presumably due to infarction, which increases over 24–48 hours.

Transient cerebral ischaemic attack (TIA) A transient episode of neurological dysfunction caused by focal brain, spinal cord or retinal ischaemia without infarction.¹

Key facts and checkpoints

• Stroke is the second most common (10–12%) cause of death in the Western world. Most are ischaemic (thrombotic or embolic), but 15–20% are haemorrhagic.

• A stroke or TIA must be considered a medical emergency.

• One in 10 patients with a TIA is likely to have a stroke shortly afterwards—usually within 2 weeks and most within 48 hours. The risk is greatest if older than 60, symptoms last more than 10 minutes and there is weakness or a speech impediment with the TIA.²

• Clinical assessment (including neurological examination) investigations and treatment should be commenced quickly.

• The best approach to stroke management is aggressive attention to primary and secondary prevention.

• The main risk factors for stroke are atrial fibrillation, hypertension, smoking, age and diabetes.

• Cardiac disease can be a source of emboli.

• Most patients with a stroke or TIA require urgent imaging to find the cause and guide treatment.

• Ideally, patients should be referred to a stroke unit ASAP—within 3 hours.

• Order a CT or MRI scan on all patients with suspected TIAs and strokes (if not referring to a stroke unit): if normal, repeat within 7 days (CT scans unreliable after 7 days). Such imaging is required to differentiate between ischaemia and haemorrhage.

• Consider the possibility of a cryptogenic stroke,¹ especially from a patent foramen ovale (PFO) (in 20–25% of population and responsible for 50% of cryptogenic strokes) in relatively young people presenting with a stroke: this leads to paradoxical emboli (from veins to the brain). PFOs may be detected by echocardiography and sealed with a percutaneous closure device, although this is not routine.

• Consider the possibility of endocarditis if there is a heart murmur.

• Keep in mind atherosclerotic disease of the aortic arch as a source of cerebral embolism.

• The place of carotid endarterectomy for asymptomatic carotid stenosis remains controversial. It should be seriously considered if the stenosis is severe, the risk of surgery is low (3% risk of major stroke), the team has proven expertise and the patient is medically fit with a good life expectancy.¹

• Carotid artery stenting for the treatment and prevention of stroke is an evolving procedure.