stroke

Stroke causes sudden loss of neurological function by disrupting
the blood supply to the brain. It is the biggest cause
of physical disability in developed countries, and a leading
cause of death. It is also common in many developing countries.
The great majority of strokes come on without warning. This
means that for most patients the aims of management are to
limit the damage to the brain, optimize recovery and prevent recurrence.
Strategies to prevent strokes are clearly important.
They concentrate on treating the vascular risk factors that
predispose to stroke, such as hypertension, hyperlipidaemia,
diabetes and smoking.
The two principal pathological processes that give rise to
stroke are occlusion of arteries, causing cerebral ischaemia or
infarction, and rupture of arteries, causing intracranial
haemorrhage (Fig. 2.1). Haemorrhage tends to be much more
destructive and dangerous than ischaemic stroke, with higher
mortality rates and a higher incidence of severe neurological
disability in survivors. Ischaemic stroke is much more common,
and has a much wider range of outcomes.