Shuichi Yamada*, Hiroyuki Nakase, Young-Soo Park, Yasushi Motoyama, Ichiro Nakagawa and Fumihiko Nishimura
Background: Subarachnoid hemorrhage (SAH) without aneurysm rupture is called SAH with unknown etiology (unknown SAH). We analyzed and report the latest study of the clinical features and prognosis of patients with unknown SAH.
Methods and Findings: The study included 21 patients who had been treated at our institution. The diagnosis of unknown SAH defined as no cause of hemorrhage like cerebral aneurysm, despite of repeated vascular examination.
Discussion: The patients’ age, sex, Glasgow coma scale on admission, use of antithrombotic drugs and presence of hypertension and diabetes were not concerned with prognosis. Only dyslipidemia had correlation with poor prognosis. The distribution or laterality of hematoma on computed tomography also has no relation with prognosis.
Conclusion: Our study showed no significant correlation between any characteristics of patient or SAH and prognosis, except dyslipidemia with poor prognosis. It is difficult to determine prognostic factors, therefore, we need careful examination and adequate treatment for the patients of unknown SAH.
English 
Spanish 
Chinese 
Russian 
French 
Japanese 
Portuguese 
Hindi