Chapter 121: Stroke and transientischaemic attacks

Glossary of terms

Stroke A focal neurological deficit lasting longer than24 hours caused by intracerebral haemorrhage orinfarction.

Stroke in evolution An enlarging neurological deficit, presumably due to infarction, which increases over24-48 hours.

Transient cerebral ischaemic attack (TIA) A transientepisode of neurological dysfunction caused byfocal brain, spinal cord or retinal ischaemia withoutinfarction.¹

Key facts and checkpoints

• Stroke is the second most common (10-12%)cause of death in the Western world. Most areischaemic (thrombotic or embolic), but 15-20% arehaemorrhagic.

• A stroke or TIA must be considered a medicalemergency.

• One in 10 patients with a TIA is likely to have astroke shortly afterwards—usually within 2 weeksand most within 48 hours. The risk is greatest ifolder than 60, symptoms last more than 10 minutesand there is weakness or a speech impedimentwith the TIA.²

• Clinical assessment (including neurologicalexamination) investigations and treatment shouldbe commenced quickly.

• The best approach to stroke management isaggressive attention to primary and secondaryprevention.

• 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 urgentimaging to find the cause and guide treatment.

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

• Order a CT or MRI scan on all patients withsuspected TIAs and strokes (if not referring to a stroke unit): if normal, repeat within 7 days (CTscans unreliable after 7 days). Such imaging isrequired to differentiate between ischaemia andhaemorrhage.

• Consider the possibility of a cryptogenic stroke,¹especially from a patent foramen ovale (PFO) (in20-25% of population and responsible for 50%of cryptogenic strokes) in relatively young peoplepresenting with a stroke: this leads to paradoxicalemboli (from veins to the brain). PFOs may bedetected by echocardiography and sealed with apercutaneous closure device, although this is notroutine.

• Consider the possibility of endocarditis if there is aheart murmur.

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

• The place of carotid endarterectomy forasymptomatic carotid stenosis remainscontroversial. It should be seriously considered ifthe stenosis is severe, the risk of surgery is low(3% risk of major stroke), the team has provenexpertise and the patient is medically fit with agood life expectancy.¹

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