Strokes occur when brain cells are deprived of oxygen because of a disruption to the blood supply (i.e. blockage or haemorrhage). The brain cells die, which causes symptoms relevant to the part of the brain affected: a sudden loss of speech, for example, or weakness or paralysis on one side of the body.  Each year around 55,000 Australians have strokes, with three quarters of these being first-time strokes. Stroke is becoming increasingly c...