Spontaneous subarachnoid haemorrhage (SAH) is a
significant cause of stroke and may lead to severe
neurological deficit or death. It is also associated with high
morbidity and mortality for patients despite optimal medical
and surgical treatment. Based on the World Health
Organization the annual incidence of spontaneous SAH
varies in different regions of the world between
2.0-22.5 per 100,000 populations with Finland and
Japan having the highest incidence and South and
Central America with lowest incidence.1