In spite of major recent advances in the treatment of aneurysmal subarachnoid hemorrhage (SAH), management of cerebral vasospasm and its consequences still remain a formidable clinical challenge. Magnesium may exhibit a range of vascular and neuronal actions that may ameliorate ischemic central nervous system insults.

(1) To determine whether i ntravenous magnesium therapy in addition to standard care can improve functional outcome in patients with aneu rysmal SAH. (2) To determine whether intravenous magnesium therapy in addition to standard care can reduce the frequency of symptomatic vasospasm.

Medline, Cochrane, Ovid, Stroke Group Trial Register and Herdin databases were searched to identify all randomized controlled trials on the use of intravenous magnesium therapy in addition to standard care versus standard care alone in patients with aneurysmal SAH. The studies were analyzed using the Review Manager 4.2 software. An estimate of the treatment effect across trials were measured using relative risks (with a 95% confidence interval) and were pooled using random effects.

Three studies involving 379 patients were included. Overall, the relative risk of intravenous magnesium therapy for poor outcome was 0.75 (95% Cl, 0.57 - 1 .0). Although there was a trend to favor the treatment group, it did not reach statistical significance. The risk of intravenous magnesi um therapy on the occurrence of symptomatic vasospasm was significantly reduced, with a RR of 0.66 (95% Cl, 0.45-0.96).

I ntravenous magnesi um therapy as adj unct to standard care in patients with aneurysmal SAH shows a trend favoring treatment with a significant reduction in symptomatic vasospasm but not enough evidence to support its effect on improving over-all functional outcome.