Subarachnoid hemorrhage in middle-Finland: incidence, early prognosis and indications for neurosurgical treatment.

The incidence of subarachnoid hemorrhage (SAH) in Middle-Finland 1976-78 was 19.4/100,000/year. The incidence increased consistently with age. The early prognosis was similar to that in earlier studies, with 25% dying on the first day, and 49% during the first 3 months after the initial bleeding. The fatality rate decreased sharply after the bleeding: of all deaths during the first 3 months, the weekly fatality rate was 65% during the 1st week, 12% during the 2nd, and 4% during the 3rd. Thereafter the weekly fatalities up to 3 months averaged 1.6%. Only 20% of the patients of the entire series were assessed as being eligible for neurosurgical treatment. Intercurrent fatal rebleeds further reduced this number. The chances of increasing the number of SAH patients suitable for neurosurgery are discussed. The timing of surgery should be earlier than in the present study (median 15 days after the bleeding) in order to avoid frequently fatal recurrences. Vertebral angiograms should be obtained from patients with no aneurysms found by bilateral carotid angiography. The upper age limit of 60 years should be abolished. By these means the proportion of SAH patients potentially eligible for neurosurgery could be increased to about 40%.