Clinical comparison of patients with angiography: Negative perimesencephalic and nonperimesencephalic subarachnoid hemorrhages.

Aims: This study aimed to compare the clinical courses, complications, and clinical outcome scores of patients with perimesencephalic (PM) and nonperimesencephalic (n-PM) subarachnoid hemorrhage (SAH) with no vascular pathology observed on cerebral angiography.

Materials and Methods: This retrospective study included 52 of 310 patients who underwent cerebral digital subtraction angiography for SAH between October 2016 and April 2018. The patients were categorized into PM and n-PM groups based on the type of hemorrhage observed on brain CT. The patients Fischer's grades, Glasgow Coma Scale scores, and World Federation of Neurosurgical Societies SAH grades were recorded. Hydrocephalus, vasospasm findings in both groups, and modified Rankin scale (mRS) scores were assessed, and vascular pathology factors (diabetes mellitus, hypertension, and smoking) were compared between the patient groups.

Results: The PM group included 30 patients, the n-PM group 22 patients. Minimal hydrocephalus was observed in two patients in the PM group and six patients developed apparent hydrocephalus in the n-PM group. Angiographic vasospasm was observed in four patients in the n-PM group but none of the patients in the PM group. On discharge, all patients in the PM group had mRS scores of 0. One patient in the n-PM group become exitus and 18 patients were discharged mRS 0, 2 for two patients, and 3 for one patient.

Conclusion: The patients with PM SAH experienced a benign course, whereas those with n-PM SAH showed a higher risk of vasospasm and hydrocephalus as well as worse exit scores.