 Spontaneous subarachnoid hemorrhage SAH is usually caused by rupture of an intracranial aneurysm, but in up to 15 of patients with spontaneous SAH, no discernible bleeding source can be identified despite of repetitive radiological imaging. Patients, at least 18 months after ictus of a non-aneurysmal SAH, received a regular mail including a letter explaining the study purpose and the postal questionnaire consisting a short-form health survey with 36 simple questions. If we didnt receive answers after three months we made telephone interviews with the patients family members or their general practitioner. 