Research into the Western literature reveals an incidence of 10-12 and of 10-11
per 100000 of the population of the U.S.A. of subarachnoid hemorrhage (SAH)
and of ruptured intracranial aneurysms respectively. In Europe the corresponding
figures vary from 6 to 24 and 3 to 10, whereas in Japan they are higher and are
found to be 21 to 24 and 15. Without doubt the management of subarachnoid
hemorrhage remains of the most important clinical problems in neurosurgical
practice world-wide.