Spontaneous Subarachnoid Hemorrhage with Negative Angiography Managed in a Stroke Unit: Clinical and Prognostic Characteristics

Background: Perimesencephalic subarachnoid hemorrhage (p-SAH) is linked to a benign prognosis compared with aneurysmal SAH. However, the outcome in nonperimesencephalic angiographically negative SAH (np-SAH) is not well established. We reviewed our experience and evaluated the clinical and prognostic differences between patients with p-SAH and np-SAH. Methods: Retrospective observational study based on data collected prospectively from all patients admitted to our hospital with SAH during the past 11 years. After selecting patients with normal angiography, we categorized them as either p-SAH or np-SAH according to the Rinkel criteria. Demographic, clinical, radiologic, and prognostic features were recorded. Results: We collected a total of 41 (12.53%) angiographically negative SAH: 17 p-SAH (41.46%) and 24 np-SAH (58%-53%). The np-SAH group included the 6 patients with Glasgow Coma Scale (GCS) less than 15 (P = .083), and all 5 patients with Hunt & Hess (H&H) scores more than II (P = .045), being the GCS = 15 and H&H less than II in the rest of np-SAH and in all of the p-SAH patients. The average hospital stay in days was longer in the np-SAH group (24 +/- 7.08) than in the p-SAH group (17 +/- 5.11; P = .55). Hydrocephalus requiring external ventricular drainage (EVD) was only recorded in the np-SAH group (29.16%, P = .029). On discharge, all patients had H&H grade less than II and modified Rankin Scale measured 3 months later was less than 2 in both groups. Conclusions: Our results agree with other studies showing a low complication rate for SAH patients with a normal angiography, especially in the p-SAH group. The prognosis appears to be less favorable in terms of a more frequent need for EVD, so a more cautious approach is recommended in this subgroup.