Therapeutic recommendations Level of Evidence A Data derived from multiple randomized clinical trials or meta-analyses Level of Evidence B Data derived from a single randomized trial or nonrandomized studies Level of Evidence C Consensus opinion of experts, case studies, or standard of care Diagnostic recommendations Level of Evidence A Data derived from multiple prospective cohort studies using a reference standard applied by a masked evaluator Level of Evidence B Data derived from a single grade A study, or 1 case-control studies, or studies using a reference standard applied by an unmasked evaluator Level of Evidence C Consensus opinion of experts 4. In addition to the size and location of the aneurysm and the patient s age and health status, it might be reasonable to consider morphological and hemody- namic characteristics of the aneurysm when discuss- ing the risk of aneurysm rupture (Class IIb; Level of Evidence B). (New recommendation) 5. Consumption of a diet rich in vegetables may lower the risk of aSAH (Class IIb; Level of Evidence B). (New recommendation) 6. It may be reasonable to offer noninvasive screening to patients with familial (at least 1 first-degree relative) aSAH and/or a history of aSAH to evaluate Table 3. Class I Recommendations Level of Evidence Recommendation A 1. Treatment of high blood pressure with antihypertensive medication is recommended to prevent ischemic stroke, intracerebral hemorrhage, and cardiac, renal, and other end-organ injury. A 2. Oral nimodipine should be administered to all patients with aSAH. (It should be noted that this agent has been shown to improve neurological outcomes but not cerebral vasospasm. The value of other calcium antagonists, whether administered orally or intravenously, remains uncertain.) B 1. Hypertension should be treated, and such treatment may reduce the risk of aSAH B 2. 