Stroke

Stroke is a condition due to lack of oxygen to a region of the brain leading to reversible or irreversible paralysis and cognitive and functional changes, or it may be fatal. About 80 percent of strokes are due to occlusion of a cerebral artery by a clot (ischaemic stroke); the remainder are due to the rupture of a cerebral or subarachnoid blood vessel (haemorrhagic stoke). Some people experience short-lived 'mini-strokes' (transient ischaemic attacks) which are due to the same underlying pathology as ischaemic stroke.

Ischaemic stroke is associated with vascular disease; advice on prevention and management is often included in guidelines covering the prevention of cardiovascular events. Aspirin reduces the risk of ischaemic stroke in individuals at increased risk and is also indicated for immediate use in acute stroke.

• Vascular disease - clopidogrel and dipyridamole, 2005 (http://guidance.nice.org.uk/TA90/?c=91497)

• Management of patients with stroke, 2002 (updated 2006) (www.sign.ac.uk/pdf/sign64.pdf)

• Diagnosis and management of peripheral arterial disease, 2006 (www.sign.ac.uk/pdf/sign89.pdf)

• Expert consensus document on the use of antiplatelet agents, 2004 (www.escardio.org/NR/rdonlyres/408F3F49-5C2B-4450-A3B2-BF11FC5A90FB/0/guidelines_Antiplatelets_FT_2004.pdf)

• Aspirin Foundation Position Papers:
When should aspirin be started after a transient ischaemic attack?
Combination therapy with warfarin

The indications for aspirin reflect a balance of its likely benefits and possible risks. Aspirin is associated with a small increase in the risk of haemorrhagic stroke and is contraindicated in patients who may have had haemorrhagic stroke.

• Aspirin Foundation Position Papers:
Aspirin and the risk of haemorrhagic stroke