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.