Subarachnoid haemorrhage has an incidence of 8.7 per 100,000 population per annum in the Netherlands. Of the intracranial aneurysm cases presenting for surgery at the Neurosurgical clinic at the Academisch Ziekenhuis Groningen between 1977 and 1987 about 33% were under the age of 40, 62.5% were under the age of 50 and 90% were under the age of 60 years. Approximately one third of all patients with aneurysmas lubarachnoid haemorrhage die or are neurologically disabled following the initial haemorrhage. While recurrent haemorrhage occurs within the next two weeks in 20 % of the survivors ... Zie: Summary