Subarachnoidal hemorrhage (SAH) is a cause of long-term disability and death. Annually about 1000 people in Finland suffer from SAH, their average age being under 50 years. SAH has a mortality rate of 12 % acutely and 40 % of patients die within a month from admission to hospital. In addition, 30 % of the surviving patients remain with neurological deficits. Most survivors of the primary insult suffer from secondary injury during the first 2-3 weeks from the insult.