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.