 The prevalence rate of intracranial aneurysms in the adult population is close to 5. Rupture risk of such aneurysms causing subarachnoid hemorrhage SAH can be substantial.Most patients suffering from an aneurysmal SAH are in their mid life, i.e., 30 to 60 years old. Aneurysmal SAH may cause disability and mortality. The present study includes a follow-up study and a cross-sectional fMRI study. The purpose of the follow-up study is to monitor patients receiving prophylactic surgical treatment of their un-ruptured aneurysms to examine whether such treatment is associated with cognitive, psychosocial andor neurologic sequela. The purpose of the cross-sectional fMRI study is to examine the relationship between memory function and brain activity among SAH patients. Memory impairment is often found among aneurysmal SAH patients. Using fMRI can possibly shed some light on whether such memory impairment may be caused by diffuse cerebral damage or a focal damage at the aneurysm site. 