ABSTRACT
A clinical analysis and follow-up study were performed with 35 cases of subarachnoid hemorrhage of unknown etiology among 217 cases of spontaneous subarachnoid hemorrhage who were diagnosed by cerebral pan-angiohraphy and brain C-T scan and treated at department of neurosurgery, Chonju Presbyterian Medical Center from 1977 to 1982. The duration of follow-up study was 6 months to 8 years(mean 4.4years). The author obtained the following results. 1) Subarachnoid hemorrhage of unknown etiology was 16% of 217 cases of spontaneous hemorrhage. 2) The incidence of subarachnoid hemorrhage of unknown etiology was high in 5th decade and higher in women. 3) Manifestations of subarachnoid hemorrhage of unknown etiology were similar to those of ruptured aneurysm. 4) When primary cerebral pan-angiography was normal, the secondary cerebral pan-angiography was not so meaningful. 5) The overall prognosis of the cases of unknown etiology was good in 30 among 35 cases(86%) who were able to return to their previous occupation. 6) Age and blood pressure were probably major prognostic factor.