Stroke is defined by the World Health Organization as a clinical syndrome consisting of 'rapidly developing clinical signs of focal (at times global) disturbance of cerebral function, lasting more than 24 h or leading to death with no apparent cause other than that of vascular origin' (1).
- a transient ischaemic attack (TIA) is defined as stroke symptoms and signs that resolve within 24 hours
- strokes result from:
- cerebral infarction (84%):
- secondary to thrombosis (53%); or
- embolus (31%)
- primary intracerebral haemorrhage (10%)
- subarachnoid haemorrhage (6%)
- a non-disabling stroke is defined as a stroke with symptoms that last for more than 24 hours but later resolve, leaving no permanent disability
- symptoms experienced depend on the part of the brain that is affected
- usually occur suddenly and without any warning
- common symptoms include loss of movement or sensation in an arm or leg, problems speaking, a drooping of one side of the face or problems with vision
- a stroke can occur at any age
- average age for stroke varies across the UK, with a median age of 77 years (interquartile range 67 to 85)
- a quarter of strokes occur in people of working age
- first-ever stroke affects 230 people per 100,000 each year, with over 80,000 people hospitalised per year in England
- the Sentinel Stroke National Audit Programme show that 13.6% of people admitted to hospital with stroke in England and Wales died (either in hospital or after being discharged from inpatient care) within 30 days
- are approximately 1.2 million stroke survivors in the UK
- risk of recurrent stroke is 26% within 5 years of a first stroke and 39% by 10 years
Notes: - there are limitations to these definitions of stroke and TIA outlined
- for example, they do not include retinal symptoms (sudden onset of monocular visual loss), which should be considered as part of the definition of stroke and TIA. The symptoms of a TIA usually resolve within minutes or a few hours at most, and anyone with continuing neurological signs when first assessed should be assumed to have had a stroke
- definition of stroke excludes transient ischaemic attacks, subdural haematomas, and infarction or haemorrhage due to infection or tumour. However, practically it is often difficult to discriminate between a small stroke and a transient ischaemic attack
- the term 'brain attack' is sometimes used to describe any neurovascular event and may be a clearer and less ambiguous term to use
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