Prognosis in subarachnoid hemorrhage of unknown etiology.

Thirty-two patients with subarachnoid hemorrhage of unknown etiology were followed for periods from 1 to 6 1/2 years. Two more patients had normal initial angiograms, but were excluded when repeat angiography revealed an aneurysm. The mortality rate in this series was 6%. There was one possible early and no late episode of rebleeding. One patient developed epilepsy. Five patients developed communicating hydrocephalus and underwent a shunting procedure. A complete recovery was observed in 12 patients. An additional eight had minimal disability, seven were more severely disabled, and three patients were totally disabled. Antifibrinolytic treatment (tranexamic acid) was given in a nonstandardized regimen to 14 patients who showed a poorer result than did the 18 untreated patients.