Approximately 85% of strokes are due to cerebral infarction, 10% to primary haemorrhage and 5% to subarachnoid haemorrhage.The risk of recurrence is 26% within five years and 39% within 10 years of a first stroke (Mohan et al, 2011).In the US, 795,000 strokes occur each year (Benjamin et al, 2017) while in the UK there are more than 100,000 (Royal College of Physicians, 2017).
Stroke affects 15 million people worldwide every year; it is estimated that five million of these will die and a further five million will be left with a permanent disability (WHO, 2002).
This makes stroke the second-leading cause of death worldwide behind ischaemic heart disease.
The WHO describes stroke as a clinical syndrome typified by “rapidly developing clinical signs of focal or global disturbance of cerebral function, lasting more than 24 hours or leading to death, with no apparent cause apart that of vascular origin” (Hatano, 1976, WHO 1965).
This definition is no longer accurate, as it does not take into account the advances that have been and continue to be made in imaging techniques and diagnostics.
This, coupled with better knowledge of brain function among professionals and greater awareness of stroke signs and symptoms among the general public, leads to earlier identification, diagnosis and treatment – which are key as stroke is a medical emergency.