Different clinical characteristics between perimesencephalic subarachnoid hemorrhage and diffuse subarachnoid hemorrhage with negative initial angiography.

AIM The purpose of this study was to compare the different clinical features, outcome and treatment strategies in patients with perimesencephalic SAH (p-SAH) and diffuse SAH (d-SAH). MATERIAL AND METHODS 83 patients with spontaneous SAH and negative initial cerebral angiography were retrospectively reviewed. RESULTS There were 49 patients with p-SAH and 34 with d-SAH. The patients with d-SAH were likely to be hypertensive and smoking and have elevated cholesterol and lactate dehydrogenase and White blood cells. 95.9% of patients with p-SAH had a Hunt&Hess grade of I-II, whereas 73.5% of patients with d-SAH had Grade I-II, 9 patients had Grade III-IV. All patients with p-SAH had a modified Fisher scale of 1-2 and a favorable outcome, whereas 47 % and 8.8% of the patients with d-SAH had a score of 1-2 and had a poor prognosis, respectively. Hydrocephalus, clinical vasospasm, re-bleeding and pneumonia were common in patients with d-SAH. CONCLUSION The initial bleeding pattern was associated with the initial clinical condition and outcome, and d-SAH might lead to a worse clinical course and outcome and might have a high risk of complications. Repeated DSA is recommended to exclude aneurysm in patients with d-SAH, whereas CT angiography was enough in patients with p-SAH.