Understanding stroke:Pathophysiology, presentation, and investigation

Stroke is an acute neurological injury in which blood supply to a part of the brain is interrupted. Five and a half million survivors of stroke are living in the world today.1 In the United States alone, half a million people have their first stroke each year, and 200 000 have a recurrent attack.2 The World Health Organization esti mates that 15 million people have strokes each year worldwide, 5.5 mil lion of which are fatal.1 In industri alised countries, stroke is the third most common single cause of death (after ischaemic heart disease and cancer). In the US, someone has an attack every 45 seconds, and there is a stroke related death every three minutes.2

Even if age specific stroke incidence remains stable or falls slightly because more people live into old age, the annual incidence will continue to rise. This increases mortality, but, because of the direct cost of treatment and the indirect costs of lost productivity, the result is a loss - of $57.9bn (£30.4bn; €45.1bn) a year in the US.2 A thorough understanding of stroke's pathophysiology, presentation, investigation, and current and future treatments is crucial.

Strokes may either be haemorrhagic or ischaemic. Eighty eight per cent of all strokes are ischaemic, 9% are due to intracerebral haemorrhage, and 3% are due to subarachnoid haemorrhage. 2