INTRODUCTION: Previous meta-analyses of magnesium sulphate infusion in the 
treatment of aneurysmal subarachnoid hemorrhage (SAH) have become outdated due 
to recently published clinical trials. Our aim was thus to perform an up-to-date 
systemic review and meta-analysis of published data on the use of magnesium 
sulphate infusion in aneurysmal SAH patients.
METHODS: A systemic review and meta-analysis of the literature was carried out 
on published randomized controlled clinical trials that investigated the 
efficacy of magnesium sulphate infusion in aneurysmal SAH patients. The results 
were analyzed with regard to delayed cerebral ischemia (DCI), delayed cerebral 
infarction, and favorable neurological outcomes at three and six months. The 
risks of bias were assessed using the Jadad criteria, with a Jadad score >3 
indicating a lower such risk. Meta-analyses are presented in terms of relative 
risk (RR) with 95% confidence intervals (CIs).
RESULTS: Six eligible studies with 875 patients were reviewed. The pooled RR for 
DCI was 0.87 (95% CI, 0.36 to 2.09; P = 0.75). That for delayed cerebral 
infarction was 0.58 (95% CI, 0.35 to 0.97; P = 0.04), although this result did 
not persist if only randomized clinical trials with a lower risk of bias were 
included (RR 0.61, 95% CI, 0.31 to 1.22; P = 0.17). The pooled RR for a 
favorable outcome at three months was 1.14 (95% CI, 0.99 to 1.31; P = 0.07), and 
that for a favorable outcome at six months was 1.08 (95% CI, 0.94 to 1.24; P = 
0.29).
CONCLUSIONS: The present findings do not lend support to a beneficial effect of 
magnesium sulphate infusion on delayed cerebral infarction. The reduction in DCI 
and improvement in the clinical outcomes of aneurysmal SAH patients following 
magnesium sulphate infusion observed in previous pilot studies are not 
confirmed, although a beneficial effect cannot be ruled out because of sample 
size limitation.