ABSTRACT
Objective To enhance recognition of the clinical and radiological features of nonaneurysmal subarachnoid hemorrhage (SAH) and its prognosis, and to provide guidance for the diagnosis and treatment in clinical practice. Methods Patients with spontaneous SAH, whose initial 3-dimensional digital subtraction angiography (DSA) were negative, received a second DSA after 2 to 3 weeks.Nonaneurysmal was diagnosed as SAH when both DSA were negative. All subjects were divided into 2 subgroups, perimesencephalic nonaneurysmal subarachnoid hemorrhage ( PNSAH ) group and nonperimesencephalic nonaneurysmal subarachnoid hemorrhage ( n-PNSAH ) group. Results Among 49 patients with nonaneurysmal SAH, 24 patients were PNSAH and 25 patients were n-PNSAH. Two patients died and 47 patients recovered and discharged with an average follow-up of 26 months. Conclusion The clinical course and prognosis of patients with PNSAH were good, better than that of patients with n-PNSAH.