Almost 13 per cent of patients are affected in precisely the opposite manner due to damaged vessels and the like, namely a haemorrhage in the brain. In either case, the supply of blood to certain regions of the brain is no longer sufficient due to a local circulatory disorder.

Strokes are one of the leading causes of long-term disability, with more than 795,000 people in the United States experiencing a stroke each year, 76% of those being first-time cases. More than half of stroke survivors aged 65 and over have reduced mobility as a result.

The symptoms of a stroke and their severity can vary considerably between individuals. They include:

• Impaired vision

• Limited field of vision

• Disturbances in spatial perception, double vision

• Speech and speech comprehension disorders

• Paralysis, numbness

• Impaired sense of touch

• Drooping at the corner of the mouth – the leg and arm may exhibit similar symptoms (e.g. drop foot and drop hand)

• Shoulder pain

• Unstable knee joint function while standing

• Torso instability

• Dizziness with uncertain gait

• Spasticity in various forms and degrees of severity